Cannibalizing or salvaging Campagnolo rear hubs
incredulous
changeable parts an owner could take advantage of as an economical way
of maintaining a bike? I'm seeing a lot of surplus low range stuff
being released into the market.
I appreciate that this namesake of a career auto recycler could find
the answer in exquisite detail by study of the parts manuals, but
knowing some of the major exchangeables would be of use to others,
too. Not expecting that features and quality are the same, just
wondering if they fit the same for the same function.
First off, are the dimensions of the hub housing the same, so that
hubs with the same number of spoke holes, across years and models can
be swapped in a wheel (keeping rim and spokes)?
Second, are the cassette hub bodies swappable, within and even across
speeds?
Third, are there some other major wearing components that are having
some here who rebuild stock a few extra of these new hubs (currently
10 speed Veloce and Mirage models) for future spare parts? Sealed
bearings, axels, cups, cones?
Harry Travis
Pine Barrens of NJ
USA
bfd
> Did Campagnolo rear hubs of the last decade have some major inter-
> changeable parts an owner could take advantage of as an economical way
> of maintaining a bike? I'm seeing a lot of surplus low range stuff
> being released into the market.
>
go back to 1999 or thereabout.
What you want are the Campy Record, Chorus and Centaur/Daytona/Athena
rear hubs with the oversized axles. These hubs started in about 1999
to 2006. After 2006, Campy only made this rear hub available as a
Record and in black (ugh!)
The key to these rear hubs is the oversized axle. All of the innards
like cones, cups, bearings and the axle are all the same. The dustcaps
on some are different, but the weigh probably varied by about 16g from
the "lightest" Record to the "heaviest" Centaur/Daytona/Athena
version.
> I appreciate that this namesake of a career auto recycler could find
> the answer in exquisite detail by study of the parts manuals, but
> knowing some of the major exchangeables would be of use to others,
> too. Not expecting that features and quality are the same, just
> wondering if they fit the same for the same function.
>
As stated above, the dustcap are a bit different and the "lower"
versions are a few grams heavier, but essentially they're all the
same!
> First off, are the dimensions of the hub housing the same, so that
> hubs with the same number of spoke holes, across years and models can
> be swapped in a wheel (keeping rim and spokes)?
>
Yup.
> Second, are the cassette hub bodies swappable, within and even across
> speeds?
>
Yup.
> Third, are there some other major wearing components that are having
> some here who rebuild stock a few extra of these new hubs (currently
> 10 speed Veloce and Mirage models) for future spare parts? Sealed
> bearings, axels, cups, cones?
>
The Veloce/Mirage are lower versions that have sealed bearings. Not
light and supposedly not very good. Similarly, after about 2006, the
Centaur line started using this lower grade hub. Here is Peter White's
thoughts on these hubs:
"Record, Chorus and Daytona/Centuar all have identical internal
components. The bearings are the same; no difference, NADA! We go to
great lengths to keep all Record, Chorus and Centaur/Daytona hubs in
stock all the time. However, Record hubs are gone until the black 2007
version arrives. For Centaur, I have 32 hole only.
For 2007, Campagnolo has discontinued most of their hubs. They'll be
selling a revised Record hubset, in ugly black only, and they'll be
selling some low grade junk with familiar names. For example, there's
a new Centaur labeled hub, but it's indescribably bad. You couldn't
pay me enough to build a wheel on one. But the really nice Chorus and
Centaur hubs are no longer made. I've been scouring the distributors
and buying up all of the older hubs I can find, so I'll have them for
a little while. Parts will be available for a long time, so don't
worry about that. And they're so well made, it shouldn't ever be an
issue anyway. Rest assured that I'll never sell you a junky low end
Campy hub. If you see it listed here, it's top quality.
I think Campy just wants to sell their over-priced wheels and doesn't
want competition from outside wheelbuilders. But when the day comes
when the only wheels you can buy that work with Campy derailleurs are
Campy's own boutique baubbles and bangles, even more people will
switch to Shimano.
If you just want a well made hub to take Campy cassettes, I also have
the Velocity hub below. It's only in black, and it's not as high
quality, but it's an excellent hub for the money. If you want a truly
top quality hub for Campy or Shimano cassettes, I also have the White
Industries H1 hubs in stock."
Forget the Veloce/Mirage and 2007-present Centaur rear hub! The oneS
to get are the 1999 to present Record and the 1999 to 2006 Chorus and
Centaur/Daytona/Athena rear hubs. Good Luck!
Hank
Totalcycling.com still has the 2006 Centaurs, 32h Grey only, for $152/
pair. I got a set from them a year ago when they still had them in
silver, and received excellent service.
bfd
>
Good price. Totalcycling also sells another hub that is Campy
compatible and got good review under another name.
The Ambrosio Zenith rear hub comes in 28-36h, available in either
black or silver color, can be bought with either Campy or Shimano
splines, weighs 264g (w/o skewers) and is only $64US:
http://www.totalcycling.com/index.php/product/HB_ZENITH_S_R.html
This hub received an excellent review by Jan H and is sold by him here
in the US for more than twice the price! Something to consider....Good
Luck!
incredulous
OK, so chopping an inferior Campagnolo hub wouldn't be a loss, if the
freehub body is what one wanted. Are these bodies worth going after,
or is Campagnolo freehub failure so rare on the top four lines so rare
as to make the question moot. I'm looking for a source of 9-10speed
freebody hubs for older 8 speed wheels.
I'm seeing replacement Record and freehubs from Campagnolo at more
than $200. But, the Ambrosio reputation preceeds, so could be fine.
And, I'll suffer the accusation of being lazy in this for the
excellence and helpfulness of the responses. I've had the experience
of finding substitutible parts from mfgs bearing different part
numbers and prices. So, not easy for an amateur. The right starter for
a small Fiat saved me a lot of money once in getting a Guzzi going,
when the alternative from Guzzi would have cost more than the $700 I
bought the bike for, 2 month's income.
Harry Travis
dusto...@mac.com
Very short on specifics, still.
What do you have, what do you want to do?
"Make us a list".
FWIW: I've had one Veloce hub in "the fleet" that has been just fine.
Those are occasionally available on ebay and elsewhere at good prices.
Otherwise, I've used Record and Chorus, so far.
FWIW2: In my limited experience, eventually everything in a wheel gets
worn out-- rim sidewalls worn thin and/or bashed, spokes get nicked in
various ways, cones and cups wear. freehubs start skipping sooner
after service (or so it seems). There comes a time when it's better
economically, including time and frustration, to chuck the lot and
start over. One "Campy Salvage" auction on ebay found a ready buyer
for an old hub shell, good for one (1) lunch, net return. What can I
say? Someone broke a spoke flange, I guess.
--D-y
incredulous
> I'm seeing replacement Record and freehubs from Campagnolo at more
> than $200. But, the Ambrosio reputation preceeds, so could be fine.
>
> Harry Travis
A cyclist from Oz likes the UK-sourced Ambrosio hub mentioned earlier
in this thread, but dug deeper. Seems Ambrosio is a licensed brand in
the UK, and the hub is not an Italian Ambrosio if such a thing exists,
but likely made by Joytech in Taiwan. A fine hub, maybe -- but not
from a direct, historic competitor of Campagnolo.
Harry Travis
incredulous
>
> Very short on specifics, still.
> What do you have, what do you want to do?
> "Make us a list".
I want to have one or two 9-11 speed Campy freehub bodies on hand for
spares. Anything inferior about the ones that come with the new 4-5
year old Campy Mirage hubs being dumped now?
Harry Travis
David Scheidt
:> I'm seeing replacement Record and freehubs from Campagnolo at more
:> Harry Travis
Well, since Ambrosio went bust in the 1960s, it's not much of a
surpise, is it? Joytech make a huge range of hubs, in quality ranging
from top-notch to abysmal, with any number of brand names on them.
All depends on what the customer wants.
--
sig 1
bfd
are compatible with other Campy rear hubs so you'll need to do your
own research :)
But one thing to consider. If you get one of the Record, Chorus,
Centaur/Daytona rear hubs with the oversized axles, there is an
additional source of parts from those who bought Campy "pre-built"
boutique wheels!
I've seen on CL, ebay and other bike classifieds where people are
parting out their Campy boutique wheels because the cost to replace
broken rims and spokes, what I would consider consumables, are too
much. IF you can get it, Campy wants anywhere from $100-250+ for rims
and proprietary spokes can be in the $4-5 each or more range. At that
point, people part out the innards from the hubs which are the exact
same parts found in the standard Record, Chorus and Centaur/Daytona.
Something to consider. Good Luck!
bfd
following about that rear hub:
"The hubs are manufactured in Taiwan. They come with Shimano- or
Campagnolo-compatible cassettes. Silver color, classic appearance,
and available in 32 and 36 holes.
I pulled apart the hubs last night, and they have cartridge bearings
like many modern hubs. However, the front hub has splash seals to
give added protection to the bearings, rather than relying only on
the rubber dust shields of the bearings themselves to keep moisture
and dirt out. The rear hub, which is in the path of spray thrown up
by the front wheel, is sealed even better. A recessed cap covers the
bearings, and a rubber O-ring seals the cap against the hub body.
It's a simple, neat design that should keep the rear hub bearings
clean.
I still prefer the adjustable bearings and double labyrinth seals of
the Maxi-Car hubs, but they are hard to find, and don't exist in a
cassette version.
The hubs are nicely finished, but the quick release, while
functional, lacks the ultimate finish of a classic Campagnolo QR. Of
course, I have a reputation for being picky... In any case, it's easy
to replace the QR with a nicer one from your toolbox, just like I do
with my Maxi-Car hubs, because the RFG quick releases that came with
them also were finished no better."
He also stated:
"I now can answer the questions people have asked:
- The hubs are about as loud as a Shimano cassette hub, but much less
noisy than some other aftermarket hubs.
- The cassette bodies are made from aluminum to save weight. This
means that you should use a high-end cassette where the large cogs
mount onto a carrier. When I tested the hub with an inexpensive
cassette with mostly individual cogs, I got some indentation in the
cassette body where the cogs had dug into the aluminum. It didn't
ruin the cassette body during my short test, but it might make the
cogs hard to remove after prolonged use. I then I switched to a
cassette with 7 cogs on a carrier, and only the three smallest as
individual cogs, and no more indenting occurred.
- The rear hub's bearings are sealed with aluminum shields and rubber
O-rings. I prefer this over many high-end hubs that have the bearings
running exposed, with only the bearing's dust shield trying to keep
the grit out. I cannot comment on how long the bearings will last
until I have worn out the first set...
- The cassette bodies are easy to remove, if you ever want to go from
a Shimano to a Campagnolo cassette or vice versa. The
Campagnolo-compatible cassette body is a few grams lighter, because
it has deeper grooves.
Overall, they are very nice hubs."
So, if you listen to Jan H and want the Ambrosio, it sounds like a
decent option. Good Luck!
AMuzi
The sealed cartridge models (VEL-MIR ) use a different
cassette body from the 'big bearing' models:
http://www.yellowjersey.org/photosfromthepast/CANEWHUB.JPG
Post 2008 hubs use a three-sided key interface between axle
and cassette body. Those two parts exchange as a set; can't
use new bodies on old axles. Can use new body with new axle
in earlier hubs.
So what you seek are 1999 through 2007 Campagnolo
REC-CHR-CEN-DAY type bodies, numbers noted in drawing linked
above. Or a new current axle and cassette body.
--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971
BigP
> On Oct 4, 11:34 pm, incredulous <travis.ha...@gmail.com> wrote:
>> Did Campagnolo rear hubs of the last decade have some major inter-
>> changeable parts an owner could take advantage of as an economical
>> way of maintaining a bike? I'm seeing a lot of surplus low range
>> stuff being released into the market.
>>
> Don't be lazy! Go to Campy's website and look up the parts manual that
> go back to 1999 or thereabout.
>
> What you want are the Campy Record, Chorus and Centaur/Daytona/Athena
Not Athena.
> rear hubs with the oversized axles. These hubs started in about 1999
> to 2006.
Great hubs, my favourites.
> After 2006, Campy only made this rear hub available as a
> Record and in black (ugh!)
And 32h only :-(
> The key to these rear hubs is the oversized axle. All of the innards
> like cones, cups, bearings and the axle are all the same. The dustcaps
> on some are different, but the weigh probably varied by about 16g from
> the "lightest" Record to the "heaviest" Centaur/Daytona/Athena
> version.
I particularly like the ability to adjust them without needing cone
spanners, or even to remove the wheel from the bike - thanks to the
threadless cones.
The Centaur/Daytona adjusting ring is plastic instead of alloy, and usually
came with a Phillips-headed screw instead of allen key.
The shells of these models are all the same, except Centaur/Daytona has
slightly less material removed from the centre and doesn't have recesses for
the spoke heads; Record has grease ports and titanium pawls.
The 5/32" bearing balls easily pop in and out of the retainers for
replacement. The balls, cones, cups are compatible with both front and rear
hubs.
>> I appreciate that this namesake of a career auto recycler could find
>> the answer in exquisite detail by study of the parts manuals, but
>> knowing some of the major exchangeables would be of use to others,
>> too. Not expecting that features and quality are the same, just
>> wondering if they fit the same for the same function.
>>
> As stated above, the dustcap are a bit different and the "lower"
> versions are a few grams heavier, but essentially they're all the
> same!
>
>> First off, are the dimensions of the hub housing the same, so that
>> hubs with the same number of spoke holes, across years and models can
>> be swapped in a wheel (keeping rim and spokes)?
>>
> Yup.
>> Second, are the cassette hub bodies swappable, within and even across
>> speeds?
>>
> Yup.
Nope. The Mirage/Veloce type is different (at least for the ~2000-2006
era).
incredulous
>
> Well, since Ambrosio went bust in the 1960s, it's not much of a
> surpise, is it?
Just went to look again at an Ambrosio Evolution box shape clincher
front wheel, black 622x13 rim and hub. Sticker on it says "Made in
Italy". Cartridge bearing. 32 spoke, each marked with an "A"on the
head, very subtly double butted.
Are you saying that Made in Italy for wheels is like Made in Italy for
olive oil [ie maybe of olives harvested in Tunisia, but we bottled it
in Italy.....or barreled it here before shipping to Teanek, NJ for
bottling and distribution].
Are the folks from Ital Tecno in New York in on this?
I tracked down a headset once, maybe with a Primax label, Mavic
looking thing I liked, and somehow came up with this Italian
manufacturer, Rudelli:
http://www.rudelli.com/bike_components/headsets.php
600, 000 headsets, they claim to have made (and have claimed for
several years) Can't find any listed on European ebay or stores (not
looking too hard) Is this, like Ambrosio, also a ghost?
Harry Travis
Harry Travis
bfd
headsets, not threadless as is the trend. I wonder who, especially in
the high end market, is still using standard threaded headsets? Good
Luck!
incredulous
Andrew, are you saying that when the next generation of old farts
comes to populate Classic Rendezvous, limited to "classic bikes" with
10 or fewer speeds and strictly manual transmissions, that one scandal
of forgeries will be discovery of axle and cassette bodies that were
born/delivered in schwarz Mirage bodies, but transplanted to shiny
Record and Chorus shells and resold as new refurbs? Zombies. The
horror.
For the first time, I'm an early adopter.
Harry Travis
AMuzi
Rudeli Italian headsets are fine quality, nice looking, not
expensive:
http://www.yellowjersey.org/kmdg.html
David Scheidt
:>
:> Well, since Ambrosio went bust in the 1960s, it's not much of a
:> surpise, is it?
:Just went to look again at an Ambrosio Evolution box shape clincher
:front wheel, black 622x13 rim and hub. Sticker on it says "Made in
:Italy". Cartridge bearing. 32 spoke, each marked with an "A"on the
:head, very subtly double butted.
No, I'm saying that Ambrosio went bust in the 60s. Someone bought the
remains. anyhthing sold now has n othing to do with the stuff of 40
years ago, outside of the name. Same thing happpened to countless
brands. Consider all the bike brands owned by pacific cycles, for
instance.
Joy-tech are the bigest manufacturer of hubs in the world, I belive.
they have a huge range of parts, some sold under their name, most made
under contract for someone else.
--
Movable type was evidently a fad. --Amanda Walker
Jobst Brandt
>> Well, since Ambrosio went bust in the 1960s, it's not much of a
>> surprise, is it?
> Just went to look again at an Ambrosio Evolution box shape clincher
> front wheel, black 622x13 rim and hub. Sticker on it says "Made in
> Italy". Cartridge bearing. 32 spoke, each marked with an "A"on the
> head, very subtly double butted.
> Are you saying that Made in Italy for wheels is like Made in Italy
> for olive oil [IE maybe of olives harvested in Tunisia, but we
> bottled it in Italy... or barreled it here before shipping to
> Teaneck, NJ for bottling and distribution].
> Are the folks from Ital Tecno in New York in on this?
> I tracked down a headset once, maybe with a Primax label, Mavic
> looking thing I liked, and somehow came up with this Italian
> manufacturer, Rudelli:
http://www.rudelli.com/bike_components/headsets.php
> 600, 000 headsets, they claim to have made (and have claimed for
> several years) Can't find any listed on European ebay or stores (not
> looking too hard). Is this, like Ambrosio, also a ghost?
Well the Rudelli head bearing is doomed to fail for the same reason
dimpled (indexed) head bearings occurred for more than a century,
fretting damage. Modern head bearings have their fretting motions
(flexing of the steertube) separated from rotary steering motions.
Today, head bearings, unlike the one in the URL, have a plain bearing
for fork swivel and a ball bearing for steering rotation. You'll
notice that the Rudelli design even believes in roller bearings. That
was a major misunderstanding of fretting damage and came and went long
ago. These guys should get some practice with automotive wheel drive
pinions and their failed tapered roller bearings... learn about
fretting failures.
Jobst Brandt
Jobst Brandt
>> Just went to look again at an Ambrosio Evolution box shape clincher
>> front wheel, black 622x13 rim and hub. Sticker on it says "Made in
>> Italy". Cartridge bearing. 32 spoke, each marked with an "A"on the
>> head, very subtly double butted.
>> Are you saying that Made in Italy for wheels is like Made in Italy for
>> olive oil [IE maybe of olives harvested in Tunisia, but we bottled it
>> in Italy... or barreled it here before shipping to Teaneck, NJ for
>> bottling and distribution].
>> Are the folks from Ital Tecno in New York in on this?
>> I tracked down a headset once, maybe with a Primax label, Mavic
>> looking thing I liked, and somehow came up with this Italian
>> manufacturer, Rudelli:
http://www.rudelli.com/bike_components/headsets.php
>> 600, 000 headsets, they claim to have made (and have claimed for
>> several years) Can't find any listed on European ebay or stores
>> (not looking too hard) Is this, like Ambrosio, also a ghost?
> What is interesting is the headsets are seem to be standard threaded
> headsets, not threadless as is the trend. I wonder who, especially
> in the high end market, is still using standard threaded headsets?
> Good Luck!
It's not the threadless steertube that ended head bearing failures,
but rather the separation of rotary and swivel motions, as Shimano did
years ago with their threaded head bearing. The threads had nothing
to do with it. In fact, I had the threads in my threaded Shimano head
bearings machined out to fit on my threadless steertube that I got to
get rid of the wobbly quill stem and its corrosion freeze-ups.
Jobst Brandt
thirty-six
You would not have experienced these problems if you had used the
appropriate lubricants.
thirty-six
> Harry Travis wrote:
> >> Well, since Ambrosio went bust in the 1960s, it's not much of a
> >> surprise, is it?
> > Just went to look again at an Ambrosio Evolution box shape clincher
> > front wheel, black 622x13 rim and hub. Sticker on it says "Made in
> > Italy". Cartridge bearing. 32 spoke, each marked with an "A"on the
> > head, very subtly double butted.
> > Are you saying that Made in Italy for wheels is like Made in Italy
> > for olive oil [IE maybe of olives harvested in Tunisia, but we
> > bottled it in Italy... or barreled it here before shipping to
> > Teaneck, NJ for bottling and distribution].
> > Are the folks from Ital Tecno in New York in on this?
> > I tracked down a headset once, maybe with a Primax label, Mavic
> > looking thing I liked, and somehow came up with this Italian
> > manufacturer, Rudelli:
>
> http://www.rudelli.com/bike_components/headsets.php
>
> > 600, 000 headsets, they claim to have made (and have claimed for
> > several years) Can't find any listed on European ebay or stores (not
> > looking too hard). Is this, like Ambrosio, also a ghost?
>
> Well the Rudelli head bearing is doomed to fail for the same reason
> dimpled (indexed) head bearings occurred for more than a century,
That is an out and out lie. Head bearing damage has only occured with
the use of modern automotive lubricants (greases) being
innappropriately used on bicycle components.
Jobst Brandt
>>>> Well, since Ambrosio went bust in the 1960s, it's not much of a
>>>> surprise, is it?
>>> Just went to look again at an Ambrosio Evolution box shape clincher
>>> front wheel, black 622x13 rim and hub. Sticker on it says "Made in
>>> Italy". Cartridge bearing. 32 spoke, each marked with an "A"on the
>>> head, very subtly double butted.
>>> Are you saying that Made in Italy for wheels is like Made in Italy
>>> for olive oil [IE maybe of olives harvested in Tunisia, but we
>>> bottled it in Italy... or barreled it here before shipping to
>>> Teaneck, NJ for bottling and distribution].
>>> Are the folks from Ital Tecno in New York in on this?
>>> I tracked down a headset once, maybe with a Primax label, Mavic
>>> looking thing I liked, and somehow came up with this Italian
>>> manufacturer, Rudelli:
http://www.rudelli.com/bike_components/headsets.php
>>> 600, 000 headsets, they claim to have made (and have claimed for
>>> several years) Can't find any listed on European ebay or stores (not
>>> looking too hard). Is this, like Ambrosio, also a ghost?
>> Well the Rudelli head bearing is doomed to fail for the same reason
>> dimpled (indexed) head bearings occurred for more than a century,
> I've never seen a dimpled taper roller bearing from any two wheeler
> steering head, at any age or mileage.
Too bad you have lived such a sheltered life that you cannot
understand ball bearing failures. You might make up for that by
reading "Rolling Bearing Analysis" by Tedric Harris:
> I've put a fair few in, to replace dimpled ball bearings though, and
> it's always cured any tendency to dimple.
You have no control over whether a steering bearing dimples or not.
It is a design problem and reasonable road riding with minimal
steering excursion.
> That includes those on motorcycles with far higher loadings than
> you'll ever see on a pedal cycle, and at higher mileages too (150,000
> good enough for you?).
It isn't the loading, but rather the fretting, caused by steertube
flex while riding straight ahead. Motorcycles don't have a suitably
flexing steertube.
> I really can't imagine why you think that a design that is perfectly
> adequate on a 1/2 ton motorcycle is going to be incapable of
> supporting a small proportion of that without failing in a fraction of
> the mileage on a bicycle.
That's because you don't understand the cause of dimples by fretting,
something that doesn't occur on most motorcycles.
> Keeping them adjusted and lubricated right is pretty much essential
> though.
So why did bicyclists put up with indexed steering for more than a
century, most of these bicycles being maintained by good mechanics?
>> fretting damage. Modern head bearings have their fretting motions
>> (flexing of the steertube) separated from rotary steering motions.
>> Today, head bearings, unlike the one in the URL, have a plain
>> bearing for fork swivel and a ball bearing for steering rotation.
>> You'll notice that the Rudelli design even believes in roller
>> bearings. That was a major misunderstanding of fretting damage and
>> came and went long ago. These guys should get some practice with
>> automotive wheel drive pinions and their failed tapered roller
>> bearings... learn about fretting failures.
You might read about dimpled head bearings before educating wreck.bike
all about it. You are treading on thin ice, so to speak.
Jobst Brandt
thirty-six
WRONG lubricant.
> You might make up for that by
> reading "Rolling Bearing Analysis" by Tedric Harris:
>
> http://tinyurl.com/nnc2xn
>
> > I've put a fair few in, to replace dimpled ball bearings though, and
> > it's always cured any tendency to dimple.
>
> You have no control over whether a steering bearing dimples or not.
Ah, you persisted with auto wheel bearing grease then?
> It is a design problem and reasonable road riding with minimal
> steering excursion.
No it's service failure, wrong lubricant.
>
> > That includes those on motorcycles with far higher loadings than
> > you'll ever see on a pedal cycle, and at higher mileages too (150,000
> > good enough for you?).
>
> It isn't the loading, but rather the fretting, caused by steertube
> flex while riding straight ahead. Motorcycles don't have a suitably
> flexing steertube.
Obviously, you'd like that corrected.
>
> > I really can't imagine why you think that a design that is perfectly
> > adequate on a 1/2 ton motorcycle is going to be incapable of
> > supporting a small proportion of that without failing in a fraction of
> > the mileage on a bicycle.
>
> That's because you don't understand the cause of dimples by fretting,
> something that doesn't occur on most motorcycles.
>
> > Keeping them adjusted and lubricated right is pretty much essential
> > though.
>
> So why did bicyclists put up with indexed steering for more than a
> century,
LIES!
> most of these bicycles being maintained by good mechanics?
A good mechanic would not be using automobile wheel bearing grease.
>
> >> fretting damage. Modern head bearings have their fretting motions
> >> (flexing of the steertube) separated from rotary steering motions.
> >> Today, head bearings, unlike the one in the URL, have a plain
> >> bearing for fork swivel and a ball bearing for steering rotation.
> >> You'll notice that the Rudelli design even believes in roller
> >> bearings. That was a major misunderstanding of fretting damage and
> >> came and went long ago. These guys should get some practice with
> >> automotive wheel drive pinions and their failed tapered roller
> >> bearings... learn about fretting failures.
>
> You might read about dimpled head bearings before educating wreck.bike
> all about it. You are treading on thin ice, so to speak.
Big shoes decrease surface pressure, something generally desirable in
bearinfgs.
>
> Jobst Brandt
Jobst Brandt
http://www.rudelli.com/bike_components/headsets.php
> WRONG lubricant.
As I said, you should read Tedric Harris's book on "Rolling Bearing
Analysis" where you would find that your assessment of dimpled
bearings is incorrect.
>> You might make up for that by reading "Rolling Bearing Analysis" by
>> Tedric Harris:
>>> I've put a fair few in, to replace dimpled ball bearings though,
>>> and it's always cured any tendency to dimple.
>> You have no control over whether a steering bearing dimples or not.
> Ah, you persisted with auto wheel bearing grease then?
Stop jumping to your favorite conclusions for not understanding the
cause of fretting failure in ball bearings.
>> It is a design problem and reasonable road riding with minimal
>> steering excursion.
> No it's service failure, wrong lubricant.
How do you explain that head bearings are now available that do not
develop dimples, even though they use the same lubricants as those of
the past? To recognize why this has occurred you would need to
understand the mechanism for fretting damage to oscillating load
bearings.
>>> That includes those on motorcycles with far higher loadings than
>>> you'll ever see on a pedal cycle, and at higher mileages too
>>> (150,000 good enough for you?).
>> It isn't the loading, but rather the fretting, caused by steertube
>> flex while riding straight ahead. Motorcycles don't have a suitably
>> flexing steertube.
> Obviously, you'd like that corrected.
It has been corrected, but not in the steertube, but rather in the
bearings. The ratio of steertube and fork blade bending diameter has
not changed. Only the design of the ball bearings has. You might
look into that before offering your lubrication excuse again.
>>> I really can't imagine why you think that a design that is
>>> perfectly adequate on a 1/2 ton motorcycle is going to be
>>> incapable of supporting a small proportion of that without failing
>>> in a fraction of the mileage on a bicycle.
>> That's because you don't understand the cause of dimples by fretting,
>> something that doesn't occur on most motorcycles.
>>> Keeping them adjusted and lubricated right is pretty much essential
>>> though.
>> So why did bicyclists put up with indexed steering for more than a
>> century,
> LIES!
That's a cheap shot. Do you really believe Campagnolo understood why
their head bearings failed so miserably and lied about it? They did
their best and it wasn't good enough.
>> most of these bicycles being maintained by good mechanics?
> A good mechanic would not be using automobile wheel bearing grease.
...and they didn't, and even if they did, so what is it that wheel
bearing grease does that is so damaging. I should remind you that
railroad shipped cars had dimpled wheel bearings and differential
pinions and their pinion tapered roller bearings from fretting, as
Tedric Harris explains in his book. Deign to read about it from an
expert who worked his engineering days at SKF bearings.
http://www.jewishexponent.com/article/21294/
I think you should be aware of this man before offering your excuse
for bearing damage. In his book he explains the symptom and its cause
unlike what you repeatedly offer here.
>>>> fretting damage. Modern head bearings have their fretting motions
>>>> (flexing of the steertube) separated from rotary steering motions.
>>>> Today, head bearings, unlike the one in the URL, have a plain
>>>> bearing for fork swivel and a ball bearing for steering rotation.
>>>> You'll notice that the Rudelli design even believes in roller
>>>> bearings. That was a major misunderstanding of fretting damage and
>>>> came and went long ago. These guys should get some practice with
>>>> automotive wheel drive pinions and their failed tapered roller
>>>> bearings... learn about fretting failures.
>> You might read about dimpled head bearings before educating wreck.bike
>> all about it. You are treading on thin ice, so to speak.
> Big shoes decrease surface pressure, something generally desirable in
> bearings.
You are working hard at making any of your analyses lose any
credibility here on wreck.bike. Just back off a bit. I am sure you
are not a mechanical engineer by education from what you have offered.
Jobst Brandt
thirty-six
A headset bearing is NOT a rolling bearing!! Your reference is
inappropriate as is your use of automotive wheel bearing grease for
everything except your nipples, I believe you prefer them dry and
erm...
>
> >> You might make up for that by reading "Rolling Bearing Analysis" by
> >> Tedric Harris:
>
> http://tinyurl.com/nnc2xn
>
> >>> I've put a fair few in, to replace dimpled ball bearings though,
> >>> and it's always cured any tendency to dimple.
> >> You have no control over whether a steering bearing dimples or not.
> > Ah, you persisted with auto wheel bearing grease then?
>
> Stop jumping to your favorite conclusions for not understanding the
> cause of fretting failure in ball bearings.
Have a bourbon and cola.
>
> >> It is a design problem and reasonable road riding with minimal
> >> steering excursion.
> > No it's service failure, wrong lubricant.
>
> How do you explain that head bearings are now available that do not
> develop dimples, even though they use the same lubricants as those of
> the past? To recognize why this has occurred you would need to
> understand the mechanism for fretting damage to oscillating load
> bearings.
'Fretting damage' as you refer it on a ball bearing headset does NOT
occur when the headset is correctly lubricated. It never has. Damage
only occurs when the incorrect lubricant for the bearing design is
used.
>
> >>> That includes those on motorcycles with far higher loadings than
> >>> you'll ever see on a pedal cycle, and at higher mileages too
> >>> (150,000 good enough for you?).
> >> It isn't the loading, but rather the fretting, caused by steertube
> >> flex while riding straight ahead. Motorcycles don't have a suitably
> >> flexing steertube.
> > Obviously, you'd like that corrected.
>
> It has been corrected, but not in the steertube, but rather in the
> bearings. The ratio of steertube and fork blade bending diameter has
> not changed. Only the design of the ball bearings has.
Balls are not spherical now??
> You might
> look into that before offering your lubrication excuse again.
No excuses, the only headset bearing failures I had were when using
auto wheel grease for lubrication. When I returned to oil, there
were no failures, when I changed to a soft calcium grease there were
no failures. Even a 'Cycle grease' gave a much improved lifespan than
auto wheel bearing grease.
>
> >>> I really can't imagine why you think that a design that is
> >>> perfectly adequate on a 1/2 ton motorcycle is going to be
> >>> incapable of supporting a small proportion of that without failing
> >>> in a fraction of the mileage on a bicycle.
> >> That's because you don't understand the cause of dimples by fretting,
> >> something that doesn't occur on most motorcycles.
> >>> Keeping them adjusted and lubricated right is pretty much essential
> >>> though.
> >> So why did bicyclists put up with indexed steering for more than a
> >> century,
> > LIES!
>
> That's a cheap shot. Do you really believe Campagnolo understood why
> their head bearings failed so miserably and lied about it? They did
> their best and it wasn't good enough.
You are lying. The complaint you have has not occured with quality
cycles for a century. No one has had to put up with 'dimpled
steering'.
>
> >> most of these bicycles being maintained by good mechanics?
> > A good mechanic would not be using automobile wheel bearing grease.
>
> ...and they didn't, and even if they did, so what is it that wheel
> bearing grease does that is so damaging.
It does not lubricate, it is meant for continuous movement where the
bearing is warmed. It is not designed for bicycle headsets which are
probably experiencing higher loads.
> I should remind you that
> railroad shipped cars had dimpled wheel bearings and differential
> pinions and their pinion tapered roller bearings from fretting, as
> Tedric Harris explains in his book. Deign to read about it from an
> expert who worked his engineering days at SKF bearings.
Irellevant. The title of the book explains it " Rolling Bearings"
not "Cycle bearings including an axially loaded small angular
articulating bearing". Thiis is why cycle engineers are more suited
to the design and specification of service than a general or auto
aengineer. The specifics of cycle bearing design are peculiar to
cycles.
>
> http://www.jewishexponent.com/article/21294/
>
> I think you should be aware of this man before offering your excuse
> for bearing damage. In his book he explains the symptom and its cause
> unlike what you repeatedly offer here.
>
> >>>> fretting damage. Modern head bearings have their fretting motions
> >>>> (flexing of the steertube) separated from rotary steering motions.
> >>>> Today, head bearings, unlike the one in the URL, have a plain
> >>>> bearing for fork swivel and a ball bearing for steering rotation.
> >>>> You'll notice that the Rudelli design even believes in roller
> >>>> bearings. That was a major misunderstanding of fretting damage and
> >>>> came and went long ago. These guys should get some practice with
> >>>> automotive wheel drive pinions and their failed tapered roller
> >>>> bearings... learn about fretting failures.
> >> You might read about dimpled head bearings before educating wreck.bike
> >> all about it. You are treading on thin ice, so to speak.
> > Big shoes decrease surface pressure, something generally desirable in
> > bearings.
>
> You are working hard at making any of your analyses lose any
> credibility here on wreck.bike. Just back off a bit. I am sure you
> are not a mechanical engineer by education from what you have offered.
I am sure you are not by your constant gaffs.
>
> Jobst Brandt
AMuzi
Trevor, roller bearing headsets are the exact subject here.
Try to keep up.
Jobst Brandt
http://www.rudelli.com/bike_components/headsets.php
>>> WRONG lubricant.
>> As I said, you should read Tedric Harris' book on "Rolling Bearing
>> Analysis" where you would find that your assessment of dimpled
>> bearings is incorrect.
> A headset bearing is NOT a rolling bearing!! Your reference is
> inappropriate as is your use of automotive wheel bearing grease for
> everything except your nipples, I believe you prefer them dry and
> erm...
can you justify your use of the term? As far as English is concerned,
rolling is what balls do whether on a flat surface or in a round
groove either straight or curved. It seems you never played ball or
you would know this and not try to weasel out on such false
pretenses... dragging in grease with it.
>>>> You might make up for that by reading "Rolling Bearing Analysis"
>>>> by Tedric Harris:
>>>>> I've put a fair few in, to replace dimpled ball bearings though,
>>>>> and it's always cured any tendency to dimple.
>>>> You have no control over whether a steering bearing dimples or
>>>> not.
>>> Ah, you persisted with auto wheel bearing grease then?
>> Stop jumping to your favorite conclusions for not understanding the
>> cause of fretting failure in ball bearings.
> Have a bourbon and cola.
Please explain your OT comment.
>>>> It is a design problem and reasonable road riding with minimal
>>>> steering excursion.
>>> No it's service failure, wrong lubricant.
>> How do you explain that head bearings are now available that do not
>> develop dimples, even though they use the same lubricants as those
>> of the past? To recognize why this has occurred you would need to
>> understand the mechanism for fretting damage to oscillating load
>> bearings.
> 'Fretting damage' as you refer it on a ball bearing headset does NOT
> occur when the headset is correctly lubricated. It never has.
> Damage only occurs when the incorrect lubricant for the bearing
> design is used.
That includes millions of such bearings that were maintained by
competent maintenance shops over a century. Where were you when you
might have advised these people... incorrectly?
>>>>> That includes those on motorcycles with far higher loadings than
>>>>> you'll ever see on a pedal cycle, and at higher mileages too
>>>>> (150,000 good enough for you?).
I see you don't read either. Motorcycles don't have a light weight
steertube as a bicycle. One that flexes with road roughness. The
motorcycle uses fork suspension so there is no fretting forces, even
with a lighter steer tube... which they don't use.
>>>> It isn't the loading, but rather the fretting, caused by
>>>> steertube flex while riding straight ahead. Motorcycles don't
>>>> have a suitably flexing steertube.
>>> Obviously, you'd like that corrected.
>> It has been corrected, but not in the steertube, but rather in the
>> bearings. The ratio of steertube and fork blade bending diameter
>> has not changed. Only the design of the ball bearings has.
> Balls are not spherical now??
Don't try so hard to be obtuse. Modern head bearings on bicycles are
pre-loaded angular contact cartridge bearings, seated on swivels that
absorb fretting motions of the flexing steertube on a plain bearing.
>> You might look into that before offering your lubrication excuse
>> again.
> No excuses, the only headset bearing failures I had were when using
> auto wheel grease for lubrication. When I returned to oil, there
> were no failures, when I changed to a soft calcium grease there were
> no failures. Even a 'Cycle grease' gave a much improved lifespan than
> auto wheel bearing grease.
Just think ho much cost you could have saved the bicycle industry if
you had revealed and instructed on how o prevent indexed steering. I
don't believe a word of it.
>>>>> I really can't imagine why you think that a design that is
>>>>> perfectly adequate on a 1/2 ton motorcycle is going to be
>>>>> incapable of supporting a small proportion of that without
>>>>> failing in a fraction of the mileage on a bicycle.
>>>> That's because you don't understand the cause of dimples by
>>>> fretting, something that doesn't occur on most motorcycles.
>>>>> Keeping them adjusted and lubricated right is pretty much
>>>>> essential though.
>>>> So why did bicyclists put up with indexed steering for more than
>>>> a century,
>>> LIES!
>> That's a cheap shot. Do you really believe Campagnolo understood
>> why their head bearings failed so miserably and lied about it?
>> They did their best and it wasn't good enough.
> You are lying. The complaint you have has not occurred with quality
> cycles for a century. No one has had to put up with 'dimpled
> steering'.
Just ask the people in the business, like Andrew Muzi or (too bad) the
late Sheldon Brown. The design change was not for naught.
>>> A good mechanic would not be using automobile wheel bearing grease.
>> ...and they didn't, and even if they did, so what is it that wheel
>> bearing grease does that is so damaging.
> It does not lubricate, it is meant for continuous movement where the
> bearing is warmed. It is not designed for bicycle headsets which are
> probably experiencing higher loads.
What characteristic of wheel bearing grease is it that causes this
effect?
>> I should remind you that railroad shipped cars had dimpled wheel
>> bearings and differential pinions and their pinion tapered roller
>> bearings from fretting, as Tedric Harris explains in his
>> book. Deign to read about it from an expert who worked his
>> engineering days at SKF bearings.
http://www.jewishexponent.com/article/21294/
> Irrelevant. The title of the book explains it " Rolling Bearings"
> not "Cycle bearings including an axially loaded small angular
> articulating bearing". This is why cycle engineers are more suited
> to the design and specification of service than a general or auto
> engineer. The specifics of cycle bearing design are peculiar to
> cycles.
>> I think you should be aware of this man before offering your excuse
>> for bearing damage. In his book he explains the symptom and its
>> cause unlike what you repeatedly offer here.
>>>>>> fretting damage. Modern head bearings have their fretting
>>>>>> motions (flexing of the steertube) separated from rotary
>>>>>> steering motions. Today, head bearings, unlike the one in the
>>>>>> URL, have a plain bearing for fork swivel and a ball bearing
>>>>>> for steering rotation. You'll notice that the Rudelli design
>>>>>> even believes in roller bearings. That was a major
>>>>>> misunderstanding of fretting damage and came and went long
>>>>>> ago. These guys should get some practice with automotive wheel
>>>>>> drive pinions and their failed tapered roller bearings... learn
>>>>>> about fretting failures.
>>>> You might read about dimpled head bearings before educating
>>>> wreck.bike all about it. You are treading on thin ice, so to
>>>> speak.
>>> Big shoes decrease surface pressure, something generally desirable
>>> in bearings.
>> You are working hard at making any of your analyses lose any
>> credibility here on wreck.bike. Just back off a bit. I am sure
>> you are not a mechanical engineer by education from what you have
>> offered. I am sure you are not by your constant gaffs.
I think most readers of this newsgroup recognize that you are making
this stuff up as you write without understanding tribological
interactions.
Jobst Brandt
thirty-six
> Trevor Jeffrey wrote:
> > A headset bearing is NOT a rolling bearing!! Your reference is
> > inappropriate as is your use of automotive wheel bearing grease for
> > everything except your nipples, I believe you prefer them dry and
> > erm...
>
> can you justify your use of the term? As far as English is concerned,
> rolling is what balls do whether on a flat surface or in a round
The title is "Rolling Bearings" not "Rolling Element Bearings". The
balls may rock and roll but that still does not make a headset bearing
a rolling bearing.
> groove either straight or curved. It seems you never played ball or
> you would know this and not try to weasel out on such false
> pretenses... dragging in grease with it.
The fact that you continue to disregard the lubrication specification
with environment as part of the service requirement of the component
indicates your low level of understanding of the subject. Correct
lubrication leads to long life bearings.
>
> >>>> You might make up for that by reading "Rolling Bearing Analysis"
> >>>> by Tedric Harris:
>
> http://tinyurl.com/nnc2xn
>
> >>>>> I've put a fair few in, to replace dimpled ball bearings though,
> >>>>> and it's always cured any tendency to dimple.
> >>>> You have no control over whether a steering bearing dimples or
> >>>> not.
> >>> Ah, you persisted with auto wheel bearing grease then?
> >> Stop jumping to your favorite conclusions for not understanding the
> >> cause of fretting failure in ball bearings.
> > Have a bourbon and cola.
>
> Please explain your OT comment.
Maybe some ice.
>
> >>>> It is a design problem and reasonable road riding with minimal
> >>>> steering excursion.
> >>> No it's service failure, wrong lubricant.
> >> How do you explain that head bearings are now available that do not
> >> develop dimples, even though they use the same lubricants as those
> >> of the past? To recognize why this has occurred you would need to
> >> understand the mechanism for fretting damage to oscillating load
> >> bearings.
> > 'Fretting damage' as you refer it on a ball bearing headset does NOT
> > occur when the headset is correctly lubricated. It never has.
> > Damage only occurs when the incorrect lubricant for the bearing
> > design is used.
>
> That includes millions of such bearings that were maintained by
> competent maintenance shops over a century. Where were you when you
> might have advised these people... incorrectly?
>
> >>>>> That includes those on motorcycles with far higher loadings than
> >>>>> you'll ever see on a pedal cycle, and at higher mileages too
> >>>>> (150,000 good enough for you?).
>
> I see you don't read either.
WTF
> Motorcycles don't have a light weight
> steertube as a bicycle. One that flexes with road roughness. The
> motorcycle uses fork suspension so there is no fretting forces, even
> with a lighter steer tube... which they don't use.
>
> >>>> It isn't the loading, but rather the fretting, caused by
> >>>> steertube flex while riding straight ahead. Motorcycles don't
> >>>> have a suitably flexing steertube.
> >>> Obviously, you'd like that corrected.
> >> It has been corrected, but not in the steertube, but rather in the
> >> bearings. The ratio of steertube and fork blade bending diameter
> >> has not changed. Only the design of the ball bearings has.
> > Balls are not spherical now??
>
> Don't try so hard to be obtuse. Modern head bearings on bicycles are
> pre-loaded angular contact cartridge bearings, seated on swivels that
> absorb fretting motions of the flexing steertube on a plain bearing.
Stop trying. Ancient headset bea5rings are also angular contact (pre-
load3ded if you like). They work fine with the correct lubricant for
the service conditions.
>
> >> You might look into that before offering your lubrication excuse
> >> again.
> > No excuses, the only headset bearing failures I had were when using
> > auto wheel grease for lubrication. When I returned to oil, there
> > were no failures, when I changed to a soft calcium grease there were
> > no failures. Even a 'Cycle grease' gave a much improved lifespan than
> > auto wheel bearing grease.
>
> Just think ho much cost you could have saved the bicycle industry if
> you had revealed and instructed on how o prevent indexed steering. I
> don't believe a word of it.
OFD COURSE YOU DONT!!
>
>
>
> >>>>> I really can't imagine why you think that a design that is
> >>>>> perfectly adequate on a 1/2 ton motorcycle is going to be
> >>>>> incapable of supporting a small proportion of that without
> >>>>> failing in a fraction of the mileage on a bicycle.
> >>>> That's because you don't understand the cause of dimples by
> >>>> fretting, something that doesn't occur on most motorcycles.
> >>>>> Keeping them adjusted and lubricated right is pretty much
> >>>>> essential though.
> >>>> So why did bicyclists put up with indexed steering for more than
> >>>> a century,
> >>> LIES!
> >> That's a cheap shot. Do you really believe Campagnolo understood
> >> why their head bearings failed so miserably and lied about it?
> >> They did their best and it wasn't good enough.
> > You are lying. The complaint you have has not occurred with quality
> > cycles for a century. No one has had to put up with 'dimpled
> > steering'.
>
> Just ask the people in the business, like Andrew Muzi or (too bad) the
> late Sheldon Brown. The design change was not for naught.
THE COMPLAINT HAS ONLY OCCURED (at least in UK) in the very latter
part of the 20th Century.
>
> >>> A good mechanic would not be using automobile wheel bearing grease.
> >> ...and they didn't, and even if they did, so what is it that wheel
> >> bearing grease does that is so damaging.
> > It does not lubricate, it is meant for continuous movement where the
> > bearing is warmed. It is not designed for bicycle headsets which are
> > probably experiencing higher loads.
>
> What characteristic of wheel bearing grease is it that causes this
> effect?
It does not lubricate an extreme pressure ocillatory bearing because
it is not designed for that. Wheel bearing grease is meant to be
heated by the continuous rolling of the bearing, something that cannot
occur with a bicycle headset. It is an innapropriate lubricant for
bicycles in general, but is espscially poor for headsets.
>
> >> I should remind you that railroad shipped cars had dimpled wheel
> >> bearings and differential pinions and their pinion tapered roller
> >> bearings from fretting, as Tedric Harris explains in his
> >> book. Deign to read about it from an expert who worked his
> >> engineering days at SKF bearings.
>
You always get personal when you've lost control. It is you however
who fails to understand the different requirements for different
bearings in different environments.
>
> BULLSHITTERt Brandt
Jobst Brandt
>>> A headset bearing is NOT a rolling bearing!! Your reference is
>>> inappropriate as is your use of automotive wheel bearing grease for
>>> everything except your nipples, I believe you prefer them dry and
>>> erm...
Try: http://tinyurl.com/3yr62km
>> Can you justify your use of the term as balls as not rolling? As
>> far as English is concerned, rolling is what balls do whether on a
>> flat surface or in a round groove either straight or curved. It
>> seems you never played ball or you would know this and not try to
>> weasel out on such false pretenses... dragging in grease with it.
> The title is "Rolling Bearings" not "Rolling Element Bearings". The
> balls may rock and roll but that still does not make a headset
> bearing a rolling bearing.
The title is "Rolling Bearing Analysis" by Tedric Harris. What is it
you think makes Mr. Harris' tome invalid for analyzing ball bearings?
> The fact that you continue to disregard the lubrication specification
> with environment as part of the service requirement of the component
> indicates your low level of understanding of the subject. Correct
> lubrication leads to long life bearings.
That you ignore what grease is, is in itself an indication that you
don't understand lubrication or the whole field of tribology.
>>>>>> You might make up for that by reading "Rolling Bearing Analysis"
>>>>>> by Tedric Harris:
>>>>>>> I've put a fair few in, to replace dimpled ball bearings
>>>>>>> though, and it's always cured any tendency to dimple.
>>>>>> You have no control over whether a steering bearing dimples or
>>>>>> not.
>>>>> Ah, you persisted with auto wheel bearing grease then?
>>>> Stop jumping to your favorite conclusions for not understanding
>>>> the cause of fretting failure in ball bearings.
>>> Have a bourbon and cola.
>> Please explain your OT comment.
> Maybe some ice.
>>>>>> It is a design problem and reasonable road riding with minimal
>>>>>> steering excursion.
>>>>> No it's service failure, wrong lubricant.
>>>> How do you explain that head bearings are now available that do
>>>> not develop dimples, even though they use the same lubricants as
>>>> those of the past? To recognize why this has occurred you would
>>>> need to understand the mechanism for fretting damage to
>>>> oscillating load bearings.
>>> 'Fretting damage' as you refer it on a ball bearing headset does
>>> NOT occur when the headset is correctly lubricated. It never has.
>>> Damage only occurs when the incorrect lubricant for the bearing
>>> design is used.
Please stop generating your own idea of bearing wear. You have no
idea of what occurs in lubricated rolling bearings. Where did you get
these ideas? It wasn't in mechanical engineering school.
>> That includes millions of such bearings that were maintained by
>> competent maintenance shops over a century. Where were you when you
>> might have advised these people... incorrectly?
>>>>>>> That includes those on motorcycles with far higher loadings than
>>>>>>> you'll ever see on a pedal cycle, and at higher mileages too
>>>>>>> (150,000 good enough for you?).
>> I see you don't read either.
I think the motorcycle example is a true example of your lack of
understanding fretting damage to bearings. Again, I suggest you read
"Rolling Bearing Analysis".
>> Motorcycles don't have a light weight steertube as a bicycle. One
>> that flexes with road roughness. The motorcycle uses fork
>> suspension so there is no fretting forces, even with a lighter
>> steer tube... which they don't use.
>>>>>> It isn't the loading, but rather the fretting, caused by
>>>>>> steertube flex while riding straight ahead. Motorcycles don't
>>>>>> have a suitably flexing steertube.
>>>>> Obviously, you'd like that corrected.
>>>> It has been corrected, but not in the steertube, but rather in the
>>>> bearings. The ratio of steertube and fork blade bending diameter
>>>> has not changed. Only the design of the ball bearings has.
>>> Balls are not spherical now??
>> Don't try so hard to be obtuse. Modern head bearings on bicycles
>> are pre-loaded angular contact cartridge ball bearings, seated on
>> swivels that absorb fretting motions of the flexing steertube on a
>> plain bearing.
> Stop trying. Ancient headset bearings are also angular contact (pre-
> loaded if you like). They work fine with the correct lubricant for
> the service conditions.
They are not pre-loaded angular contact cartridge ball bearings, but
ball bearings whose clearance is adjusted to near zero at the outset,
but developing fretting dimples give them the undesirable backlash
while riding. If that clearance is adjusted away, the bearing locks
into the dimples giving an indexed steering that homes as bearing
balls drop into dimples during steering motions.
>>>> You might look into that before offering your lubrication excuse
>>>> again.
>>> No excuses, the only headset bearing failures I had were when
>>> using auto wheel grease for lubrication. When I returned to oil,
>>> there were no failures, when I changed to a soft calcium grease
>>> there were no failures. Even a 'Cycle grease' gave a much
>>> improved lifespan than auto wheel bearing grease.
Oh! Now it seems to be the grease that is too hard and needs to be
"soft".
>> Just think how much cost you could have saved the bicycle industry
>> if you had revealed and instructed on how o prevent indexed
>> steering. I don't believe a word of it.
> OFD COURSE YOU DONT!!
>>>>>>> I really can't imagine why you think that a design that is
>>>>>>> perfectly adequate on a 1/2 ton motorcycle is going to be
>>>>>>> incapable of supporting a small proportion of that without
>>>>>>> failing in a fraction of the mileage on a bicycle.
>>>>>> That's because you don't understand the cause of dimples by
>>>>>> fretting, something that cannot occur on most motorcycles.
>>>>>>> Keeping them adjusted and lubricated right is pretty much
>>>>>>> essential though.
>>>>>> So why did bicyclists put up with indexed steering for more
>>>>>> than a century,
>>>>> LIES!
>>>> That's a cheap shot. Do you really believe Campagnolo understood
>>>> why their head bearings failed so miserably and lied about it?
>>>> They did their best and it wasn't good enough.
>>> You are lying. The complaint you have has not occurred with
>>> quality cycles for a century. No one has had to put up with
>>> 'dimpled steering'.
>> Just ask the people in the business, like Andrew Muzi or (too bad) the
>> late Sheldon Brown. The design change was not for naught.
> THE COMPLAINT HAS ONLY OCCURED (at least in UK) in the very latter
> part of the 20th Century.
Maybe that is when you started riding bicycles. Indexed steering has
been around for a long time and was also present in steering gears of
autos until power steering and rack & pinion steering was introduced.
You probably missed that with your head in the sand, so to speak.
>>>>> A good mechanic would not be using automobile wheel bearing
>>>>> grease.
Why not? What do you know about that grease that no one else seems to
know?
>>>> ...and they didn't, and even if they did, so what is it that
>>>> wheel bearing grease does that is so damaging.
>>> It does not lubricate, it is meant for continuous movement where
>>> the bearing is warmed. It is not designed for bicycle headsets
>>> which are probably experiencing higher loads.
SO why is it used at all, and why do oil companies make it?
>> What characteristic of wheel bearing grease is it that causes this
>> effect?
> It does not lubricate an extreme pressure ocillatory bearing because
> it is not designed for that. Wheel bearing grease is meant to be
> heated by the continuous rolling of the bearing, something that
> cannot occur with a bicycle headset. It is an innapropriate
> lubricant for bicycles in general, but is espscially poor for
> headsets.
I think you made that up right now. What heats the grease other than
braking? On long steady highways the bearings do not get warm.
>> BULLSHITTERt Brandt
Oh! How polite!
Jobst Brandt
Jobst Brandt
http://www.rudelli.com/bike_components/headsets.php
> Except by choosing the most appropriate type of bearing. And the
> most suitable lubricant. And a reasonable service interval.
There have been no head bearings that did not dimple until the present
design that I described.
>>> That includes those on motorcycles with far higher loadings than
>>> you'll ever see on a pedal cycle, and at higher mileages too
>>> (150,000 good enough for you?).
>> It isn't the loading, but rather the fretting, caused by steertube
>> flex while riding straight ahead. Motorcycles don't have a suitably
>> flexing steertube.
> Well, it seems many bicycles don't either.
Only ones with compound bearings that take up steertube flex in a
plain bearing and steering rotation in ball bearings... See Shimano
and Crane Creek.
> Maybe floppy steertubes are something that needs to be banished
> along with drillium?
I see, you are in the Trevor Jeffrey engineering school. Please spare
us the stories.
> Or is it that slightly more flexible for blades don't transmit the
> same level of shock loading to the steerer?
Fork blades are stiffer than the steertube in the fore and aft
direction. Just inspect the dimension in that direction and that
there are two fork blades... on purpose.
> Either way, allowing the bearing to pivot is treating the symptoms,
> not the cause.
It is the cause, and that is why motorcycles don't have the problem.
Get a motorcycle fork for your bicycle if you think that will make
your bicycle lighter and more durable.
> Maybe you also think that fitting flexible axles to railway vehicles
> would improve the suspension? Same principle.
>>> I really can't imagine why you think that a design that is
>>> perfectly adequate on a 1/2 ton motorcycle is going to be
>>> incapable of supporting a small proportion of that without failing
>>> in a fraction of the mileage on a bicycle.
>> That's because you don't understand the cause of dimples by
>> fretting, something that doesn't occur on most motorcycles.
> On the contrary, it used to be commonplace. Right up to when they
> started fitting taper roller bearings as standard. Strange that.
Tapered roller bearings are not a solution as the bicycle industry
discovered, after a brief attempt at using them. They generated
linear radial dimples even faster than ball bearings made oval
dimples. Under magnification you'll notice that the dimples are matte
finish rather than shiny smooth as Brinell dents are. That is because
they aren't dents, but rather fretting erosion of thousands of
weld-and-break-outs from the races caused by lubrication failure, the
classic mode in fretting damage.
>>> Keeping them adjusted and lubricated right is pretty much
>>> essential though.
>> So why did bicyclists put up with indexed steering for more than a
>> century, most of these bicycles being maintained by good mechanics?
> Nobody I've ever know "put up with" indexed steering - they replaced
> the bearings and learned to keep them adjusted and lubricated.
There was no escape, while replacing bearings was an expensive way of
dodging the issue for a short time.
>>>> fretting damage. Modern head bearings have their fretting
>>>> motions (flexing of the steertube) separated from rotary steering
>>>> motions.
>>>> Today, head bearings, unlike the one in the URL, have a plain
>>>> bearing for fork swivel and a ball bearing for steering
>>>> rotation. You'll notice that the Rudelli design even believes
>>>> in roller bearings. That was a major misunderstanding of
>>>> fretting damage and came and went long ago. These guys should
>>>> get some practice with automotive wheels, drive pinions and
>>>> their failed tapered roller bearings... learn about fretting
>>>> failures.
>> You might read about dimpled head bearings before educating
>> wreck.bike all about it. You are treading on thin ice, so to
>> speak.
> That from someone who never realised that they occurred on
> motorcycles.
Rarely, and no one worries about it today. As I mentioned, cars had
the problem with dimpled steering gears. I worked on them as a child
in grade school. We had it on Fords and Chevies.
> Of course, I didn't need to read about that - I saw it, felt it, and
> learned to fix it for myself.
You didn't fix it (get rid of it), only spent money on new races once
in a while. That's what most riders did.
Jobst Brandt
Tom Sherman °_°
> [...]
> Fork blades are stiffer than the steertube in the fore and aft
> direction. Just inspect the dimension in that direction and that
Uh, I have four bicycles [1] with monoblades connecting the front hub to
the headset, and there are other commercial examples, most commonly the
Cannondale "Lefty".
[1] e.g.
<http://www.flickr.com/photos/19704682@N08/1940444786/sizes/z/in/set-72157619269124601/>.
--
Tom Sherman - 42.435731,-83.985007
I am a vehicular cyclist.
Jobst Brandt
>> http://www.rudelli.com/bike_components/headsets.php
> Rubbish.
>>>>> That includes those on motorcycles with far higher loadings than
>>>>> you'll ever see on a pedal cycle, and at higher mileages too
>>>>> (150,000 good enough for you?).
>>>> It isn't the loading, but rather the fretting, caused by
>>>> steertube flex while riding straight ahead. Motorcycles don't
>>>> have a suitably flexing steertube.
>>> Well, it seems many bicycles don't either.
>> Only ones with compound bearings that take up steertube flex in a
>> plain bearing and steering rotation in ball bearings... See Shimano
>> and Crane Creek.
>>> Maybe floppy steertubes are something that needs to be banished
>>> along with drillium?
>> I see, you are in the Trevor Jeffrey engineering school. Please
>> spare us the stories.
>>> Or is it that slightly more flexible for blades don't transmit the
>>> same level of shock loading to the steerer?
>> Fork blades are stiffer than the steertube in the fore and aft
>> direction. Just inspect the dimension in that direction and that
>> there are two fork blades... on purpose.
>>> Either way, allowing the bearing to pivot is treating the
>>> symptoms, not the cause.
>> It is the cause, and that is why motorcycles don't have the
>> problem.
> As you have been told, they did. I've seen it, a very small amount
> of research by you would confirm that is was a common problem at
> least until the late '80s, and the only reason you can possibly be
> denying it is because you prefer to ignore all the evidence that
> runs counter to your theories.
I stopped riding M/C when I switched to bicycles, many years ago.
None of the M/Cs with which I worked had dimpled head bearings. Those
were mainly Triumph. Norton, Ariel, and Vincent motorcycles along with
a BSA Bantam two stroke that I used for going to the parts shop.
>> Get a motorcycle fork for your bicycle if you think that will make
>> your bicycle lighter and more durable.
> Just avoiding stupid light steerers and using taper rollers is
> sufficient.
As you see, there is a solution and that is to not use rigidly
positioned ball bearing races while sticking with current fork weight,
even if it is threadless.
>>> Maybe you also think that fitting flexible axles to railway vehicles
>>> would improve the suspension? Same principle.
What does that have to do with head bearings and their design? I see
no parallel in the principle because RR trucks don't mount on
steertubes and don't have rolling bearings for steering rotation.
>>>>> I really can't imagine why you think that a design that is
>>>>> perfectly adequate on a 1/2 ton motorcycle is going to be
>>>>> incapable of supporting a small proportion of that without
>>>>> failing in a fraction of the mileage on a bicycle.
>>>> That's because you don't understand the cause of dimples by
>>>> fretting, something that doesn't occur on most motorcycles.
>>> On the contrary, it used to be commonplace. Right up to when they
>>> started fitting taper roller bearings as standard. Strange that.
None of the M/Cs I experienced had fretting damage to the head
bearings, although after the fact it seems possible.
>> Tapered roller bearings are not a solution as the bicycle industry
>> discovered, after a brief attempt at using them. They generated
>> linear radial dimples even faster than ball bearings made oval
>> dimples. Under magnification you'll notice that the dimples are
>> matte finish rather than shiny smooth as Brinell dents are. That
>> is because they aren't dents, but rather fretting erosion of
>> thousands of weld-and-break-outs from the races caused by
>> lubrication failure, the classic mode in fretting damage.
> If you are any kind of engineer you would know that fretting damage
> cannot occur unless the lubrication film is broken down. This does
> not happen under the lower bearing pressures of a line contact
> bearing unless the lubrication is severely neglected or you mount
> the bearings on something so inadequate that it flexes to allow all
> the load to fall on one or two rollers.
That IS the definition of fretting damage. The needle head bearings
for bicycles had no shortage of fretting dimples. That's why they
are gone!
>>>>> Keeping them adjusted and lubricated right is pretty much
>>>>> essential though.
>>>> So why did bicyclists put up with indexed steering for more than a
>>>> century, most of these bicycles being maintained by good mechanics?
>>> Nobody I've ever know "put up with" indexed steering - they
>>> replaced the bearings and learned to keep them adjusted and
>>> lubricated.
>> There was no escape, while replacing bearings was an expensive way
>> of dodging the issue for a short time.
> Millions of riders of traditional upright bicycles would disagree
> with you.
>>>>>> fretting damage. Modern head bearings have their fretting
>>>>>> motions (flexing of the steertube) separated from rotary
>>>>>> steering motions.
>>>>>> Today, head bearings, unlike the one in the URL, have a plain
>>>>>> bearing for fork swivel and a ball bearing for steering
>>>>>> rotation. You'll notice that the Rudelli design even believes
>>>>>> in roller bearings. That was a major misunderstanding of
>>>>>> fretting damage and came and went long ago. These guys should
>>>>>> get some practice with automotive wheels, drive pinions and
>>>>>> their failed tapered roller bearings... learn about fretting
>>>>>> failures.
>>>> You might read about dimpled head bearings before educating
>>>> wreck.bike all about it. You are treading on thin ice, so to
>>>> speak.
>>> That from someone who never realised that they occurred on
>>> motorcycles.
Fretting damage to rolling bearings occurs wherever such bearings are
used to hold a static position for any period. Just read "Rolling
Bearing Analysis".
>> Rarely, and no one worries about it today. As I mentioned, cars
>> had the problem with dimpled steering gears. I worked on them as a
>> child in grade school. We had it on Fords and Chevies.
> So was that caused by flexible components?
It was caused by oscillating contact. Again, read "Rolling Bearing
Analysis" where the subject is explained in detail.
>>> Of course, I didn't need to read about that - I saw it, felt it, and
>>> learned to fix it for myself.
And you probably didn't need to go to school either, because you
learned all that while maturing.
>> You didn't fix it (get rid of it), only spent money on new races
>> once in a while. That's what most riders did.
> Yeah - I can live with once every 150,000 miles. Of course, they
> may not last that long if you don't maintain them.
It was more like 50 miles. Stop faking it.
> But you don't seem to be able to get your story straight.
> You say it never happened to motorcycle head bearings at the same time
> as saying that most riders kept replacing bearings in order to live
> with it. You can't have it both ways.
There you go putting words into my writing. Where did I say it
"never" occurred? Fretting damage attacks any rolling element bearing
receiving oscillating loads. That's how steering gears failed in cars
of old from driving on straight roads, just as bicycle head bearings
do. A rack & pinion steering gear will not come to the rescue of
bicycle head bearings as it did for cars, something the plain swiveling
head bearing did.
Jobst Brandt
Jobst Brandt
> the perfect time to write:
>> Fork blades are stiffer than the steertube in the fore and aft
>> direction. Just inspect the dimension in that direction and that
>> there are two fork blades... on purpose.
> Maybe you should compare the dimensions of the traditional tapered
> and curved fork blade with that of the steerer.
Oh! You believe the curl in the fork is to absorb road shock. That
part of the fork does not flex measurably. Its job is to set steering
trail, as you may have noticed with todays (ugly) straight blade forks
that are angled from the fork crown to achieve trail with respect to
the steertube axis.
> You can then try to make an engineering case of how two very small
> diameter tubes are stiffer than one tube of more than twice the
> diameter. Good luck with that.
Don't move! You are standing in deep shit. The fork blades are not
flexing suspension elements. That job is done by pneumatic tires and
top & downtube flex of the frame. I hope you noticed what gets bent
when a bicycle is ridden into a wall. On the other hand, we have seen
plenty of pictures of squirrels in front wheels that break the fork
off at the crown, not at the thin end near the dropouts.
Jobst Brandt
Jobst Brandt
http://www.rudelli.com/bike_components/headsets.php
> Rubbish.
>>>>> That includes those on motorcycles with far higher loadings than
>>>>> you'll ever see on a pedal cycle, and at higher mileages too
>>>>> (150,000 good enough for you?).
>>>> It isn't the loading, but rather the fretting, caused by
>>>> steertube flex while riding straight ahead. Motorcycles don't
>>>> have a suitably flexing steertube.
>>> Well, it seems many bicycles don't either.
>> Only ones with compound bearings that take up steertube flex in a
>> plain bearing and steering rotation in ball bearings... See Shimano
>> and Crane Creek.
>>> Maybe floppy steertubes are something that needs to be banished
>>> along with drillium?
>> I see, you are in the Trevor Jeffrey engineering school. Please
>> spare us the stories.
>>> Or is it that slightly more flexible for blades don't transmit the
>>> same level of shock loading to the steerer?
>> Fork blades are stiffer than the steertube in the fore and aft
>> direction. Just inspect the dimension in that direction and that
>> there are two fork blades... on purpose.
>>> Either way, allowing the bearing to pivot is treating the
>>> symptoms, not the cause.
>> It is the cause, and that is why motorcycles don't have the
>> problem.
> As you have been told, they did. I've seen it, a very small amount
> of research by you would confirm that is was a common problem at
> least until the late '80s, and the only reason you can possibly be
> denying it is because you prefer to ignore all the evidence that
> runs counter to your theories.
I stopped riding M/C when I switched to bicycles, many years ago.
None of the M/Cs with which I worked had dimpled head bearings. Those
were mainly Triumph. Norton, Ariel, and Vincent motorcycles along with
a BSA Bantam two stroke that I used for going to the parts shop.
>> Get a motorcycle fork for your bicycle if you think that will make
>> your bicycle lighter and more durable.
> Just avoiding stupid light steerers and using taper rollers is
> sufficient.
As you see, there is a solution and that is to not use rigidly
positioned ball bearing races while sticking with current fork weight,
even if it is threadless.
>>> Maybe you also think that fitting flexible axles to railway vehicles
>>> would improve the suspension? Same principle.
What does that have to do with head bearings and their design? I see
no parallel in the principle because RR trucks don't mount on
steertubes and don't have rolling bearings for steering rotation.
>>>>> I really can't imagine why you think that a design that is
>>>>> perfectly adequate on a 1/2 ton motorcycle is going to be
>>>>> incapable of supporting a small proportion of that without
>>>>> failing in a fraction of the mileage on a bicycle.
>>>> That's because you don't understand the cause of dimples by
>>>> fretting, something that doesn't occur on most motorcycles.
>>> On the contrary, it used to be commonplace. Right up to when they
>>> started fitting taper roller bearings as standard. Strange that.
None of the M/Cs I experienced had fretting damage to the head
bearings, although after the fact it seems possible.
>> Tapered roller bearings are not a solution as the bicycle industry
>> discovered, after a brief attempt at using them. They generated
>> linear radial dimples even faster than ball bearings made oval
>> dimples. Under magnification you'll notice that the dimples are
>> matte finish rather than shiny smooth as Brinell dents are. That
>> is because they aren't dents, but rather fretting erosion of
>> thousands of weld-and-break-outs from the races caused by
>> lubrication failure, the classic mode in fretting damage.
> If you are any kind of engineer you would know that fretting damage
> cannot occur unless the lubrication film is broken down. This does
> not happen under the lower bearing pressures of a line contact
> bearing unless the lubrication is severely neglected or you mount
> the bearings on something so inadequate that it flexes to allow all
> the load to fall on one or two rollers.
That IS the definition of fretting damage. The needle head bearings
for bicycles had no shortage of fretting dimples. That's why they
are gone!
>>>>> Keeping them adjusted and lubricated right is pretty much
>>>>> essential though.
>>>> So why did bicyclists put up with indexed steering for more than a
>>>> century, most of these bicycles being maintained by good mechanics?
>>> Nobody I've ever know "put up with" indexed steering - they
>>> replaced the bearings and learned to keep them adjusted and
>>> lubricated.
>> There was no escape, while replacing bearings was an expensive way
>> of dodging the issue for a short time.
> Millions of riders of traditional upright bicycles would disagree
> with you.
>>>>>> fretting damage. Modern head bearings have their fretting
>>>>>> motions (flexing of the steertube) separated from rotary
>>>>>> steering motions.
>>>>>> Today, head bearings, unlike the one in the URL, have a plain
>>>>>> bearing for fork swivel and a ball bearing for steering
>>>>>> rotation. You'll notice that the Rudelli design even believes
>>>>>> in roller bearings. That was a major misunderstanding of
>>>>>> fretting damage and came and went long ago. These guys should
>>>>>> get some practice with automotive wheels, drive pinions and
>>>>>> their failed tapered roller bearings... learn about fretting
>>>>>> failures.
>>>> You might read about dimpled head bearings before educating
>>>> wreck.bike all about it. You are treading on thin ice, so to
>>>> speak.
>>> That from someone who never realised that they occurred on
>>> motorcycles.
Fretting damage to rolling bearings occurs wherever such bearings are
used to hold a static position for any period. Just read "Rolling
Bearing Analysis".
>> Rarely, and no one worries about it today. As I mentioned, cars
>> had the problem with dimpled steering gears. I worked on them as a
>> child in grade school. We had it on Fords and Chevies.
> So was that caused by flexible components?
It was caused by oscillating contact. Again, read "Rolling Bearing
Analysis" where the subject is explained in detail.
>>> Of course, I didn't need to read about that - I saw it, felt it, and
>>> learned to fix it for myself.
And you probably didn't need to go to school either, because you
learned all that while maturing.
>> You didn't fix it (get rid of it), only spent money on new races
>> once in a while. That's what most riders did.
> Yeah - I can live with once every 150,000 miles. Of course, they
thirty-six
> > Yeah - I can live with once every 150,000 miles. Of course, they
> > may not last that long if you don't maintain them.
>
> It was more like 50 miles. Stop faking it.
You are not just bullshitting as usual, you are totally
unfLlckingbelievable. Don't you get it, you were doing it wrong.
You're scaffolder's frame won't help either. Perhaps you should stop
imaginning you are 7'4" tall.
thirty-six
> Phil W Lee wrote:
> > the perfect time to write:
> >> Fork blades are stiffer than the steertube in the fore and aft
> >> direction. Just inspect the dimension in that direction and that
> >> there are two fork blades... on purpose.
> > Maybe you should compare the dimensions of the traditional tapered
> > and curved fork blade with that of the steerer.
>
> Oh! You believe the curl in the fork is to absorb road shock.
That's primarily the job of the wheel, although you managed to fLlck
up a perfectly competent design there by making your wheels as rigid
as you could by overtensioning the spokes almost to the point of
spontaneous buckling. PILLOCK!
> part of the fork does not flex measurably. Its job is to set steering
> trail, as you may have noticed with todays (ugly) straight blade forks
> that are angled from the fork crown to achieve trail with respect to
> the steertube axis.
>
> > You can then try to make an engineering case of how two very small
> > diameter tubes are stiffer than one tube of more than twice the
> > diameter. Good luck with that.
>
> Don't move! You are standing in deep shit. The fork blades are not
> flexing suspension elements. That job is done by pneumatic tires and
> top & downtube flex of the frame. I hope you noticed what gets bent
> when a bicycle is ridden into a wall.
Not that I'd do it, but I'd prefer my wheel to crush.
Please prove how strong your wheel is!
> On the other hand, we have seen
> plenty of pictures of squirrels in front wheels that break the fork
> off at the crown, not at the thin end near the dropouts.
Get some squirrel slicing spokes, cost a few bob more, but should stop
you fretting.
>
> Jobst Brandt
Jobst Brandt
> I think the Vincent had taper rollers as standard - I'd be very
> surprised if any of the others did, although some Ariel's had them if
> they were specified for sidecar use (those models were beefed up all
> round)
>>>> Get a motorcycle fork for your bicycle if you think that will
>>>> make your bicycle lighter and more durable.
>>> Just avoiding stupid light steerers and using taper rollers is
>>> sufficient.
>> As you see, there is a solution and that is to not use rigidly
>> positioned ball bearing races while sticking with current fork
>> weight, even if it is threadless.
>>>>> Maybe you also think that fitting flexible axles to railway
>>>>> vehicles would improve the suspension? Same principle.
>> What does that have to do with head bearings and their design? I
>> see no parallel in the principle because RR trucks don't mount on
>> steertubes and don't have rolling bearings for steering rotation.
> But a flexible axle could give more suspension movement to the
> vehicle (just what you claim for the steertube). But the railway
> companies never regarded that as desirable - you Nat springing, you
> fit it in places where it doesn't screw up bearings or make more
> complicated bearing design necessary.
It's not flexing in an RR application. RR wheels turn and don't fret.
>>>>>>> I really can't imagine why you think that a design that is
>>>>>>> perfectly adequate on a 1/2 ton motorcycle is going to be
>>>>>>> incapable of supporting a small proportion of that without
>>>>>>> failing in a fraction of the mileage on a bicycle.
>>>>>> That's because you don't understand the cause of dimples by
>>>>>> fretting, something that doesn't occur on most motorcycles.
>>>>> On the contrary, it used to be commonplace. Right up to when they
>>>>> started fitting taper roller bearings as standard. Strange that.
Well, maybe if your experience is so, you ought to explain to the
doubters what caused the problem on M/C's.
>> None of the M/Cs I experienced had fretting damage to the head
>> bearings, although after the fact it seems possible.
> Standard conversion kits were available in the '70's and '80's not
> only through magazines but from many local motorcycle dealers. Once
> the industry started fitting them as standard equipment, the kits
> disappeared.
> I must have fitted several dozen, as not only did I fit them to all
> my own bikes but all my mates had me help out with theirs, once they
> all knew that I had done it already.
So what was the explanation for the occurrence if it was so common?
>>>> Tapered roller bearings are not a solution as the bicycle
>>>> industry discovered, after a brief attempt at using them. They
>>>> generated linear radial dimples even faster than ball bearings
>>>> made oval dimples. Under magnification you'll notice that the
>>>> dimples are matte finish rather than shiny smooth as Brinell
>>>> dents are. That is because they aren't dents, but rather
>>>> fretting erosion of thousands of weld-and-break-outs from the
>>>> races caused by lubrication failure, the classic mode in fretting
>>>> damage.
Tapered roller bearings are not immune to fretting damage as you can
discover in "Rolling Bearing Analysis". Therefore, I find that an
expensive and ineffective design change. Tapered rollers don't fit in
the same space as a ball bearing that it is to replace.
>>> If you are any kind of engineer you would know that fretting
>>> damage cannot occur unless the lubrication film is broken down.
>>> This does not happen under the lower bearing pressures of a line
>>> contact bearing unless the lubrication is severely neglected or
>>> you mount the bearings on something so inadequate that it flexes
>>> to allow all the load to fall on one or two rollers.
I'm glad you noticed that connection. That IS fretting damage and is
the only way it occurs.
>> That IS the definition of fretting damage. The needle head
>> bearings for bicycles had no shortage of fretting dimples. That's
>> why they are gone!
> And nothing at all to do with the fact that taper roller bearings
> are something you can get easily and cheaply at a bearing factor,
> instead of having to go to an LBS to by specialist parts at a
> premium. And of course, the maker may be able to claim a couple of
> ounces of weight reduction from the flexible steering tube.
You cannot get them to fit readily where ball bearings were designed.
>>>>>>> Keeping them adjusted and lubricated right is pretty much
>>>>>>> essential though.
>>>>>> So why did bicyclists put up with indexed steering for more
>>>>>> than a century, most of these bicycles being maintained by good
>>>>>> mechanics?
>>>>> Nobody I've ever know "put up with" indexed steering - they
>>>>> replaced the bearings and learned to keep them adjusted and
>>>>> lubricated.
Talk to the bike shop folks who ministered to these riders over the
years, and consider why the swiveling cartridge bearing was introduced
by Shimano.
>>>> There was no escape, while replacing bearings was an expensive
>>>> way of dodging the issue for a short time.
>>> Millions of riders of traditional upright bicycles would disagree
>>> with you.
>>>>>>>> For fretting damage. Modern head bearings have their
>>>>>>>> fretting motions (flexing of the steertube) separated from
>>>>>>>> rotary steering motions.
>>>>>>>> Today, head bearings, unlike the one in the URL, have a
>>>>>>>> plain bearing for fork swivel and a ball bearing for
>>>>>>>> steering rotation. You'll notice that the Rudelli design
>>>>>>>> even believes in roller bearings. That was a major
>>>>>>>> misunderstanding of fretting damage and came and went long
>>>>>>>> ago. These guys should get some practice with automotive
>>>>>>>> wheels, drive pinions and their failed tapered roller
>>>>>>>> bearings... learn about fretting
>>>>>>>> failures.
>>>>>> You might read about dimpled head bearings before educating
>>>>>> wreck.bike all about it. You are treading on thin ice, so to
>>>>>> speak.
>>>>> That from someone who never realised that they occurred on
>>>>> motorcycles.
How did one notice ball bearing dimples on motorcycles that have
enough engine vibration to completely obscure such motion and sound?
>> Fretting damage to rolling bearings occurs wherever such bearings
>> are used to hold a static position on a vibrating machine for any
>> period. Just read "Rolling Bearing Analysis".
> So nothing to do with the rocking from the steer tube? Just
> breakdown of lubrication film, which takes high loadings which are
> much greater in ball bearings, with their almost point contact with
> the races instead of rollers, with their line contact.
I think you should consider that even railways do not displace water
from rails with the polished steel wheels on shiny rails and must use
sand under the wheels to maintain traction. Liquids in thin films do
not behave as fluidly as most people imagine. The same goes for oil in
rolling bearings.
>>>> Rarely, and no one worries about it today. As I mentioned, cars
>>>> had the problem with dimpled steering gears. I worked on them as
>>>> a child in grade school. We had it on Fords and Chevies.
>>> So was that caused by flexible components?
>> It was caused by oscillating contact. Again, read "Rolling Bearing
>> Analysis" where the subject is explained in detail.
> So is it oscillating contact from micro-movements of the steering,
> or is it off-axis rocking, from flexing in the steerer?
It is involuntary wheel steering from road roughness that causes
side-to-side motion in the steering gear, damaging bearings and tooth
flanks of the mechanism.
> What I'm saying is that if you remove the problem of flexing in the
> steerer, the remaining stresses are easily dealt with by using line
> contact bearings instead of point contact ones, as they lower the
> peak load and leave it at a level that most decent quality
> lubrication can cope with perfectly adequately (although the
> frequency of repubrication will depend on choice of lubricant). EP
> additives stink, but molybdenum disulphide forms a very strong, very
> low friction, and highly tenuous layer on the metal components, and
> is easy and inexpensive to get (but is black, so don't get it on
> anything you care about the cosmetic appearance of).
As I mentioned repeatedly, fretting damages roller bearings as fast as
ball bearings. Bicycle needle bearings demonstrated that adequately
and automotive wheel and differential tapered roller bearings did
likewise.
>>>>> Of course, I didn't need to read about that - I saw it, felt it,
>>>>> and learned to fix it for myself.
>> And you probably didn't need to go to school either, because you
>> learned all that while maturing.
> I fully agree that I learned far more of use out of school than in
> school. Some of those things got taught in school later, but many
> didn't. And even those subjects that school did catch up on, they
> left out most of the explanations of WHY things worked that way
> which my father (a chartered engineer) and mother (head of a large
> school's maths department) were particularly good at.
> So much of school was spent helping the other kids understand the
> things I already did.
Apparently you didn't, because you failed bearing analysis and
fretting. I think you suffered from hubris.
>>>> You didn't fix it (get rid of it), only spent money on new races
>>>> once in a while. That's what most riders did.
>>> Yeah - I can live with once every 150,000 miles. Of course, they
>>> may not last that long if you don't maintain them.
>> It was more like 50 miles. Stop faking it.
> I never once had to make a further replacement of steering head
> bearings on a motorcycle once I had fitted taper rollers instead of
> balls, One of the motorcycles managed an additional 150,000 miles
> after that treatment, and the steering head was still fine, although
> most of the rest of the bike was falling apart by then and it was
> parted for spares. The frame and forks went together, so I've no
> idea what the remaining life was after that.
It was possible to ignore indexed steering. I know of folks who
didn't recognize from where the chatter in their forks arose.
>>> But you don't seem to be able to get your story straight.
>>> You say it never happened to motorcycle head bearings at the same
>>> time as saying that most riders kept replacing bearings in order
>>> to live with it. You can't have it both ways.
>> There you go putting words into my writing. Where did I say it
>> "never" occurred?
> In your statement:
>>>>>> That's because you don't understand the cause of dimples by
>>>>>> fretting, something that doesn't occur on most motorcycles.
>> Fretting damage attacks any rolling element bearing receiving
>> oscillating loads. That's how steering gears failed in cars of old
>> from driving on straight roads, just as bicycle head bearings do.
>> A rack & pinion steering gear will not come to the rescue of
>> bicycle head bearings as it did for cars, something the plain
>> swiveling head bearing did.
> My Jaguar XJ didn't suffer from indexing of the needle rollers in
> it's suspension linkages either, although the owners club reported
> it as possible in badly maintained and poorly lubricated examples.
Cars suffered from "homing" in the steering gear, apparent from slop
in the straight ahead position that, when adjusted, caused binding to
either side of straight ahead.
Jobst Brandt
Jobst Brandt
>>> the perfect time to write:
>>>> Fork blades are stiffer than the steertube in the fore and aft
>>>> direction. Just inspect the dimension in that direction and that
>>>> there are two fork blades... on purpose.
>>> Maybe you should compare the dimensions of the traditional tapered
>>> and curved fork blade with that of the steerer.
>> Oh! You believe the curl in the fork is to absorb road shock.
>> That part of the fork does not flex measurably. Its job is to set
>> steering trail, as you may have noticed with todays (ugly) straight
>> blade forks that are angled from the fork crown to achieve trail
>> with respect to the steertube axis.
> You can test it if you like - just by fitting a wire between the
> front axle and steering head and observing that it slackens briefly
> over bumps.
You'd need to attach it between the eyelet at the rear of the dropout
and the brake bolt to see whether the fork articulates. Running it up
to the top of the steertube would include steertube flex. Suspension
flex is not generated in the fork blades.
>>> You can then try to make an engineering case of how two very small
>>> diameter tubes are stiffer than one tube of more than twice the
>>> diameter. Good luck with that.
I think you may have to make some measurements to assure yourself of
your error.
>> Don't move! You are standing in deep shit. The fork blades are
>> not flexing suspension elements. That job is done by pneumatic
>> tires and top & downtube flex of the frame. I hope you noticed
>> what gets bent when a bicycle is ridden into a wall. On the other
>> hand, we have seen plenty of pictures of squirrels in front wheels
>> that break the fork off at the crown, not at the thin end near the
>> dropouts.
> Of course they do - that's where they hit it!
I think any frame builder can clear you up on your misconception.
Jobst Brandt
thirty-six
> Jobst Brandt <jbra...@sonic.net> considered 11 Oct 2010 14:23:43 GMT
> the perfect time to write:
>
> >I think any frame builder can clear you up on your misconception.
>
> Well, if your assertion is correct, the material and shape of the fork
> blades can have no impact on comfort or handling.
>
> I don't know of any frame builder who would agree with that assertion.
Nor any rider who has changed to a different gauge. There I am at
13st still riding hard
(occassionally) on SL blades because they are comfortable and help
maintain road contact.
thirty-six
No the subject is headsets and their correct installation and
lubrication. The ball and cone bearing is the most appropriate for a
bicycle when properly lfitted and lubricated.
thirty-six
> Trevor Jeffrey wrote:
> The title is "Rolling Bearing Analysis" by Tedric Harris. What is it
> you think makes Mr. Harris' tome invalid for analyzing ball bearings?
Irrelevant. The discussion is specific to bicycle headsets, not
covered by Harris.
>
> > The fact that you continue to disregard the lubrication specification
> > with environment as part of the service requirement of the component
> > indicates your low level of understanding of the subject. Correct
> > lubrication leads to long life bearings.
>
> That you ignore what grease is, is in itself an indication that you
> don't understand lubrication or the whole field of tribology.
Personal again. I have a sufficient understanding of lubrication
mediums and their suitability of application. I am not here to claim
I've a bigger head than you.
> >>> 'Fretting damage' as you refer it on a ball bearing headset does
> >>> NOT occur when the headset is correctly lubricated. It never has.
> >>> Damage only occurs when the incorrect lubricant for the bearing
> >>> design is used.
>
> Please stop generating your own idea of bearing wear. You have no
> idea of what occurs in lubricated rolling bearings. Where did you get
> these ideas? It wasn't in mechanical engineering school.
The learning of suitability or not of lubricants for headsets came
directly from me using bicycles and changing lubricants. Castrol LM
was possibly the worst performer.
>
> > Stop trying. Ancient headset bearings are also angular contact (pre-
> > loaded if you like). They work fine with the correct lubricant for
> > the service conditions.
>
> They are not pre-loaded angular contact cartridge ball bearings,
Then you've been doing it wrong.
> but
> ball bearings whose clearance is adjusted to near zero at the outset,
You should nip up from that, it's what you get when you pay an
experienced bicycle mechanic.
> but developing fretting dimples give them the undesirable backlash
> while riding. If that clearance is adjusted away, the bearing locks
> into the dimples giving an indexed steering that homes as bearing
> balls drop into dimples during steering motions.
You know that bit you had to adjust to remove the play, that's the
amount you should have nipped up on your replacement.
>
> >>>> You might look into that before offering your lubrication excuse
> >>>> again.
> >>> No excuses, the only headset bearing failures I had were when
> >>> using auto wheel grease for lubrication. When I returned to oil,
> >>> there were no failures, when I changed to a soft calcium grease
> >>> there were no failures. Even a 'Cycle grease' gave a much
> >>> improved lifespan than auto wheel bearing grease.
>
> Oh! Now it seems to be the grease that is too hard and needs to be
> "soft".
#
Yes the grease requires a viscocity of low levels for it is not drawn
on to the balls in the same way as a wheel bearing is.
Funny that the bikes I rode dated from 1930's onward, all with
original headsets running in oil. So after 40 or 50 years mixture of
use and idleness the headsets still performed flawlessly. I was
persuaded when I could afford my own new bikes that grease was the
thing and various concoctions purporting to be better than the rest
were duly presented each year. Nah, oil was best in headsets. I
eventually switched to using calcium grease which has the advantage of
showing some binding before lubrication is lost.
>
> >>>>> A good mechanic would not be using automobile wheel bearing
> >>>>> grease.
>
> Why not? What do you know about that grease that no one else seems to
> know?
It gets drawn over the rolling element to lubricate it, too heavy for
a headset, a bicycle may travel miles without turning the few degrees
necessary for an element to make a revolution and the bearing surfaces
become dry as they are repeatedly squashed and the lubricant pumped
away from the contact area due to the high pressure there.
>
> >>>> ...and they didn't, and even if they did, so what is it that
> >>>> wheel bearing grease does that is so damaging.
> >>> It does not lubricate, it is meant for continuous movement where
> >>> the bearing is warmed. It is not designed for bicycle headsets
> >>> which are probably experiencing higher loads.
>
> SO why is it used at all, and why do oil companies make it?
They make money by selling it to servicing companies and fleet
operators of motor vehicles.
Service intervals are usually specified by the manufacturer of the
components which are far far greater than where the grease is
missappropriately used on bicycle headsets. You claim yours only
lasted fifty miles before failure. I believe that was also down to
innappropriate tension put on the steerer tube as well as the
unsuitable selection of grease.
>
> >> What characteristic of wheel bearing grease is it that causes this
> >> effect?
> > It does not lubricate an extreme pressure ocillatory bearing because
> > it is not designed for that. Wheel bearing grease is meant to be
> > heated by the continuous rolling of the bearing, something that
> > cannot occur with a bicycle headset. It is an innapropriate
> > lubricant for bicycles in general, but is espscially poor for
> > headsets.
>
> I think you made that up right now. What heats the grease other than
> braking? On long steady highways the bearings do not get warm.
Yes they do. Use an infra-red thermometer on aq cloudy day and you
can see the temperature rise with ease.
>
Jobst Brandt
> High pressures on oscillating point contacts breaking down
> lubrication film.
That is called fretting damage. Where is the disagreement with this
assessment.
>>>> None of the M/Cs I experienced had fretting damage to the head
>>>> bearings, although after the fact it seems possible.
>>> Standard conversion kits were available in the '70's and '80's not
>>> only through magazines but from many local motorcycle dealers.
>>> Once the industry started fitting them as standard equipment, the
>>> kits disappeared.
>>> I must have fitted several dozen, as not only did I fit them to
>>> all my own bikes but all my mates had me help out with theirs,
>>> once they all knew that I had done it already.
So how did these M/C s need head bearing replacements if it didn't
occur. I suspect the conversions ceased because they caused no
improvement, just as the bicycle roller bearing units didn't. It was
all a big misunderstanding and today we have the compound ball and
plain bearing headsets that don't subject the rolling elements of the
bearings to off axis skewing.
>>So what was the explanation for the occurrence if it was so common?
> High pressures on oscillating point contacts breaking down
> lubrication film.
>>>>>> Tapered roller bearings are not a solution as the bicycle
>>>>>> industry discovered, after a brief attempt at using them. They
>>>>>> generated linear radial dimples even faster than ball bearings
>>>>>> made oval dimples. Under magnification you'll notice that the
>>>>>> dimples are matte finish rather than shiny smooth as Brinell
>>>>>> dents are. That is because they aren't dents, but rather
>>>>>> fretting erosion of thousands of weld-and-break-outs from the
>>>>>> races caused by lubrication failure, the classic mode in
>>>>>> fretting damage.
>> Tapered roller bearings are not immune to fretting damage as you
>> can discover in "Rolling Bearing Analysis". Therefore, I find that
>> an expensive and ineffective design change. Tapered rollers don't
>> fit in the same space as a ball bearing that it is to replace.
> So I imagined all the ones that I changed on all the motorcycles?
> The ones that had been fitted with ball bearings and I changed to
> taper rollers?
If they persisted in their use, they are probably dead today.
> I can give you examples from current parts catalogues where the
> external dimensions of a taper roller and a ball bearing are
> identical, so you are clearly bullshitting here.
> Just for an example, look up "Stronglight A9".
It is exactly the Stronglight headsets that made the syndrome apparent
as did the dimples in my upper head bearing in the forward and
rearward quadrants... along with Tedric Harris' tome on "Rolling
Bearing Analysis".
> And of course, no bearing is immune to fretting damage in the
> absence of suitable lubricant.
Not so. There is no suitable lubricant to prevent it if the
undesirable bearing motion occurs.
>>>>> If you are any kind of engineer you would know that fretting
>>>>> damage cannot occur unless the lubrication film is broken down.
>>>>> This does not happen under the lower bearing pressures of a line
>>>>> contact bearing unless the lubrication is severely neglected or
>>>>> you mount the bearings on something so inadequate that it flexes
>>>>> to allow all the load to fall on one or two rollers.
>> I'm glad you noticed that connection. That IS fretting damage and
>> is the only way it occurs.
> From lubrication breakdown, yes.
That is the definition of fretting damage.
> As long as a film of lubricant is maintained between the components,
> fretting is impossible. The higher the loading at the load
> interface, the more difficult it becomes to maintain that film.
I don't think you understand lubrication films and their durability,
and how fretting can upset the interaction.
> You pointed out examples of car suspension bearings fretting, and
> I'm sure you don't regard that as being due to angular displacement
> of the bearing axis, yet you maintain that this is the ONLY
> mechanism for the same thing happening on bicycle steering head
> bearings.
It results from oscillating motions without major rotation. Rotation
replenishes failed lubrication films that have been broken by
fretting. That is how ball bearings survive when bearing balls are
fully rotating or even for a partial continuous rotation.
>>>> That IS the definition of fretting damage. The needle head
>>>> bearings for bicycles had no shortage of fretting dimples.
>>>> That's why they are gone!
>>> And nothing at all to do with the fact that taper roller bearings
>>> are something you can get easily and cheaply at a bearing factor,
>>> instead of having to go to an LBS to by specialist parts at a
>>> premium. And of course, the maker may be able to claim a couple
>>> of ounces of weight reduction from the flexible steering tube.
>> You cannot get them to fit readily where ball bearings were
>> designed.
> Except for the ones that are the same dimensions.
...and failed to prevent further fretting damage. The classics were
with auto wheel and differential bearings, along with gear failure in
steering and pinions. You might investigate the various failed
patents for steering gears by Ross, Gemmer, Saginaw, and others who
tried. All of which failed and were replaced by rack-and-pinion that
is far cruder than these elegant designs.
> The ones I fitted to motorcycles certainly didn't require alteration
> of the bearing seats on either head tube or steerer, and gave an
> identical stack height.
That doesn't mean they solved the problem, if there was a fretting
problem.
>>>>>>>>> Keeping them adjusted and lubricated right is pretty much
>>>>>>>>> essential though.
>>>>>>>> So why did bicyclists put up with indexed steering for more
>>>>>>>> than a century, most of these bicycles being maintained by
>>>>>>>> good mechanics?
>>>>>>> Nobody I've ever know "put up with" indexed steering - they
>>>>>>> replaced the bearings and learned to keep them adjusted and
>>>>>>> lubricated.
>> Talk to the bike shop folks who ministered to these riders over the
>> years, and consider why the swiveling cartridge bearing was
>> introduced by Shimano.
> Well, they wouldn't want to admit that they'd over-tightened the
> steerer, would they?
They didn't! You cant ride an over tightened steerer, especially not
no-hands something all good bikies do on road and track alike.
>>>>>> There was no escape, while replacing bearings was an expensive
>>>>>> way of dodging the issue for a short time.
>>>>> Millions of riders of traditional upright bicycles would
>>>>> disagree with you.
Please, Andrew Muzi, speak up. You are being accused in this thread.
>>>>>>>>>> For fretting damage. Modern head bearings have their
>>>>>>>>>> fretting motions (flexing of the steertube) separated from
>>>>>>>>>> rotary steering motions.
>>>>>>>>>> Today, head bearings, unlike the one in the URL, have a
>>>>>>>>>> plain bearing for fork swivel and a ball bearing for
>>>>>>>>>> steering rotation. You'll notice that the Rudelli design
>>>>>>>>>> even believes in roller bearings. That was a major
>>>>>>>>>> misunderstanding of fretting damage and came and went long
>>>>>>>>>> ago. These guys should get some practice with automotive
>>>>>>>>>> wheels, drive pinions and their failed tapered roller
>>>>>>>>>> bearings... learn about fretting failures.
>>>>>>>> You might read about dimpled head bearings before educating
>>>>>>>> wreck.bike all about it. You are treading on thin ice, so to
>>>>>>>> speak.
>>>>>>> That from someone who never realised that they occurred on
>>>>>>> motorcycles.
>> How did one notice ball bearing dimples on motorcycles that have
>> enough engine vibration to completely obscure such motion and sound
>> (chattering head bearings when the front end is bounced)?
> Notchy low speed cornering and hideous handling at higher speeds, if
> you hadn't been checking it properly at normal maintenance
> intervals. Basically the whole handling degrades into "pig on
> roller-skates" territory.
I don't get your analogy. Fretted head bearings did not cause a loss
of control in the limits most of us experienced. It was mainly the
chattering front end that warned that it was getting worse.
> In this country it was easily picked up at the annual mandatory
> safety check (MOT test), on which it had it's own entry on the list
> of mandatory checks, and an entire section in the testers manual
> specifying exactly how the check should be made.
I don't recall ever being subjected to a "safety check" and I've been
rinding bike for more than 70 years. Who performs thee checks?
> That seems to be an amazingly comprehensive provision for something
> that according to you just doesn't happen (or did you change your
> mind on that now? it's hard to keep track)
Please explain what you mean by this apparently facetious comment.
>>>> Fretting damage to rolling bearings occurs wherever such bearings
>>>> are used to hold a static position on a vibrating machine for any
>>>> period. Just read "Rolling Bearing Analysis".
>>> So nothing to do with the rocking from the steer tube? Just
>>> breakdown of lubrication film, which takes high loadings which are
>>> much greater in ball bearings, with their almost point contact
>>> with the races instead of rollers, with their line contact.
That is a static position of the bicycle riding in a straight line
while road vibrations oscillate flex in the steertube. Please explain
the point you are trying to make.
>> I think you should consider that even railways do not displace
>> water from rails with the polished steel wheels on shiny rails and
>> must use sand under the wheels to maintain traction. Liquids in
>> thin films do not behave as fluidly as most people imagine. The
>> same goes for oil in rolling bearings.
> I don't seem to be the one suffering from a misunderstanding of
> lubricant films here, unless you can explain how fretting can occur
> even where the film is maintained.
The film cannot be maintained in the presence of fretting. That is
where the problem lies.
>>>>>> Rarely, and no one worries about it today. As I mentioned,
>>>>>> cars had the problem with dimpled steering gears. I worked on
>>>>>> them as a child in grade school. We had it on Fords and
>>>>>> Chevrolets.
>>>>> So was that caused by flexible components?
The driver's control of the steering wheel was flexible as was the
steering oscillation of the wheels that have a "roll radius" about
which they turn steer, a radius designed to keep the steering linkage
under tension. Wheel center lies outside of the king-pin for each
front wheel (in spite of having been replaced by ball joints).
>>>> It was caused by oscillating contact. Again, read "Rolling
>>>> Bearing Analysis" where the subject is explained in detail.
>>> So is it oscillating contact from micro-movements of the steering,
>>> or is it off-axis rocking, from flexing in the steerer?
>> It is involuntary wheel steering from road roughness that causes
>> side-to-side motion in the steering gear, damaging bearings and
>> tooth flanks of the mechanism.
> It would be far easier if you just answered the question as asked
> instead of obfusticating it. You seem to be agreeing that it was
> the first (very small oscillations of the steering), but seem to be
> trying to phrase it differently. Is this so you can claim later
> that you never agreed with my analysis?
With what part of fretting did is disagree?
>>> What I'm saying is that if you remove the problem of flexing in
>>> the steerer, the remaining stresses are easily dealt with by using
>>> line contact bearings instead of point contact ones, as they lower
>>> the peak load and leave it at a level that most decent quality
>>> lubrication can cope with perfectly adequately (although the
>>> frequency of re-lubrication will depend on choice of lubricant).
>>> EP additives stink, but molybdenum disulphide forms a very strong,
>>> very low friction, and highly tenuous layer on the metal
>>> components, and is easy and inexpensive to get (but is black, so
>>> don't get it on anything you care about the cosmetic appearance
>>> of).
How do you remove the problem of flexing in the steertube. I see not
way around that although making a bearing that is not affected by it
has been demonstrated.
>> As I mentioned repeatedly, fretting damages roller bearings as fast
>> as ball bearings. Bicycle needle bearings demonstrated that
>> adequately and automotive wheel and differential tapered roller
>> bearings did likewise.
> Your understanding is flawed, as I've demonstrated by actual
> real-world examples to the contrary.
I don't think you have, at least not to the people working on the
problem and their solutions. You might talk to the Cane Creek people.
If Shimano is not as easily reachable.
http://www.canecreek.com/component-headsets
where you can see the solution to the problem.
> Of course, one confounding factor is that it's clearly possible to
> wreck any bearing by poor installation or inadequate maintenance.
Do you understand why these new head bearings are not affected by
steertube flex?
>>>>>>> Of course, I didn't need to read about that - I saw it, felt
>>>>>>> it, and learned to fix it for myself.
>>>> And you probably didn't need to go to school either, because you
>>>> learned all that while maturing.
>>> I fully agree that I learned far more of use out of school than in
>>> school. Some of those things got taught in school later, but many
>>> didn't. And even those subjects that school did catch up on, they
>>> left out most of the explanations of WHY things worked that way
>>> which my father (a chartered engineer) and mother (head of a large
>>> school's maths department) were particularly good at.
>>> So much of school was spent helping the other kids understand the
>>> things I already did.
>> Apparently you didn't, because you failed bearing analysis and
>> fretting. I think you suffered from hubris.
> You've shown that your "understanding" of the subject does not align
> with what actually happens in the real world. This proves that it
> is you that has failed.
I don't see that you demonstrated what actually happens.
>>>>>> You didn't fix it (get rid of it), only spent money on new
>>>>>> races once in a while. That's what most riders did.
>>>>> Yeah - I can live with once every 150,000 miles. Of course,
>>>>> they may not last that long if you don't maintain them.
>>>> It was more like 50 miles. Stop faking it.
>>> I never once had to make a further replacement of steering head
>>> bearings on a motorcycle once I had fitted taper rollers instead
>>> of balls, One of the motorcycles managed an additional 150,000
>>> miles after that treatment, and the steering head was still fine,
>>> although most of the rest of the bike was falling apart by then
>>> and it was parted for spares. The frame and forks went together,
>>> so I've no idea what the remaining life was after that.
>> It was possible to ignore indexed steering. I know of folks who
>> didn't recognize from where the chatter in their forks arose.
> It may have been possible to ignore it for a while, but in this
> country it would be identified at MOT test and the vehicle banned
> from road use until repaired and retested.
Who performs these tests, that I seem have to missed in all my
bicycling days.
> I'm not sure why anyone would want to ignore their bike (motor or
> pedal) handling like a three legged cow in a sandpit, but the need
> to test for it in the MOT shows that there really are people that
> stupid or insensitive.
As I mentioned, it does not seriously affect handling, and that his
how it can progress to an discomforting noise.
>>>>> But you don't seem to be able to get your story straight.
I think you stand fairly alone in that perception.
>>>>> You say it never happened to motorcycle head bearings at the
>>>>> same time as saying that most riders kept replacing bearings in
>>>>> order to live with it. You can't have it both ways.
>>>> There you go putting words into my writing. Where did I say it
>>>> "never" occurred?
>>> In your statement:
>>>>>>>> That's because you don't understand the cause of dimples by
>>>>>>>> fretting, something that doesn't occur on most motorcycles.
I think you overlooked the word "most".
>>>> Fretting damage attacks any rolling element bearing receiving
>>>> oscillating loads. That's how steering gears failed in cars of
>>>> old from driving on straight roads, just as bicycle head bearings
>>>> do. A rack & pinion steering gear will not come to the rescue of
>>>> bicycle head bearings as it did for cars, something the plain
>>>> swiveling head bearing did.
>>> My Jaguar XJ didn't suffer from indexing of the needle rollers in
>>> it's suspension linkages either, although the owners club reported
>>> it as possible in badly maintained and poorly lubricated examples.
I am unfamiliar with the suspension on that car and take your word for
it.
>> Cars suffered from "homing" in the steering gear, apparent from
>> slop in the straight ahead position that, when adjusted, caused
>> binding to either side of straight ahead.
> I don't think most people would be surprised by the revelation that
> things wear most in the places where most use is made of them. It
> is only an issue if that wear is faster than should be expected,
> when you need to consider the reason, which can be due to design,
> installation or maintenance inadequacies.
Nothing gets more use than rod and main bearings in cars that get far
more rotations than most other bearings in cars. I think your
judgment on that "rule" is misplaced.
Jobst Brandt
Jobst Brandt
> From lubrication breakdown, yes.
> mind on that now? It's hard to keep track.)
thirty-six
> > lubrication film.
>
> That is called fretting damage. Where is the disagreement with this
> assessment.
You do!
>
> > I can give you examples from current parts catalogues where the
> > external dimensions of a taper roller and a ball bearing are
> > identical, so you are clearly bullshitting here.
> > Just for an example, look up "Stronglight A9".
>
> It is exactly the Stronglight headsets that made the syndrome apparent
> as did the dimples in my upper head bearing in the forward and
> rearward quadrants... along with Tedric Harris' tome on "Rolling
> Bearing Analysis".
WHat are you on about, I have a Stronglight A9 installed on my No1
bike and it's been there for over ten years without disassembly.
There is no indexed steering. It oozes out a silvery sludge, but
there certainly is no indexing. You really LOOK for problems which DO
NOT EXIST!
>
> > And of course, no bearing is immune to fretting damage in the
> > absence of suitable lubricant.
>
> Not so. There is no suitable lubricant to prevent it if the
> undesirable bearing motion occurs.
" THE ancients got it wrong" again. You really must give this up.
>
> >>>>> If you are any kind of engineer you would know that fretting
> >>>>> damage cannot occur unless the lubrication film is broken down.
> >>>>> This does not happen under the lower bearing pressures of a line
> >>>>> contact bearing unless the lubrication is severely neglected or
> >>>>> you mount the bearings on something so inadequate that it flexes
> >>>>> to allow all the load to fall on one or two rollers.
> >> I'm glad you noticed that connection. That IS fretting damage and
> >> is the only way it occurs.
> > From lubrication breakdown, yes.
>
> That is the definition of fretting damage.
>
> > As long as a film of lubricant is maintained between the components,
> > fretting is impossible. The higher the loading at the load
> > interface, the more difficult it becomes to maintain that film.
>
> I don't think you understand lubrication films and their durability,
> and how fretting can upset the interaction.
Jester.
>
>
> It results from oscillating motions without major rotation. Rotation
> replenishes failed lubrication films that have been broken by
> fretting. That is how ball bearings survive when bearing balls are
> fully rotating or even for a partial continuous rotation.
>
> ...and failed to prevent further fretting damage. The classics were
>
> That doesn't mean they solved the problem, if there was a fretting
> problem.
>
> >>>>>>>>> Keeping them adjusted and lubricated right is pretty much
> >>>>>>>>> essential though.
> >>>>>>>> So why did bicyclists put up with indexed steering for more
> >>>>>>>> than a century, most of these bicycles being maintained by
> >>>>>>>> good mechanics?
> >>>>>>> Nobody I've ever know "put up with" indexed steering - they
> >>>>>>> replaced the bearings and learned to keep them adjusted and
> >>>>>>> lubricated.
> >> Talk to the bike shop folks who ministered to these riders over the
> >> years, and consider why the swiveling cartridge bearing was
> >> introduced by Shimano.
> > Well, they wouldn't want to admit that they'd over-tightened the
> > steerer, would they?
>
> They didn't! You cant ride an over tightened steerer, especially not
> no-hands something all good bikies do on road and track alike.
It is undertightening which permits greater bending in a steeer tube.
The tension on the steer tube should be "just so". When you get it
right along with refreshing the lubtricant, the headset lasts many
tens of thousands of miles.
>
> Please, Andrew Muzi, speak up. You are being accused in this thread.
I've not seen it.
> > Notchy low speed cornering and hideous handling at higher speeds, if
> > you hadn't been checking it properly at normal maintenance
> > intervals. Basically the whole handling degrades into "pig on
> > roller-skates" territory.
>
> I don't get your analogy.
It's the introductory act before the band for the barn dance. You
have little understanding, of English traditions.
> Fretted head bearings did not cause a loss
> of control in the limits most of us experienced. It was mainly the
> chattering front end that warned that it was getting worse.
You never experienced tyre scrub either, what's new?
>
> > In this country it was easily picked up at the annual mandatory
> > safety check (MOT test), on which it had it's own entry on the list
> > of mandatory checks, and an entire section in the testers manual
> > specifying exactly how the check should be made.
>
> I don't recall ever being subjected to a "safety check" and I've been
> rinding bike for more than 70 years. Who performs thee checks?
On behalf of VOSA (formerly Ministry of Transport), local authorised
and certificated motor technicians.
>
> > That seems to be an amazingly comprehensive provision for something
> > that according to you just doesn't happen (or did you change your
> > mind on that now? it's hard to keep track)
>
> Please explain what you mean by this apparently facetious comment.
>
> >>>> Fretting damage to rolling bearings occurs wherever such bearings
> >>>> are used to hold a static position on a vibrating machine for any
> >>>> period. Just read "Rolling Bearing Analysis".
> >>> So nothing to do with the rocking from the steer tube? Just
> >>> breakdown of lubrication film, which takes high loadings which are
> >>> much greater in ball bearings, with their almost point contact
> >>> with the races instead of rollers, with their line contact.
>
> That is a static position of the bicycle riding in a straight line
> while road vibrations oscillate flex in the steertube. Please explain
> the point you are trying to make.
>
> >> I think you should consider that even railways do not displace
> The film cannot be maintained in the presence of fretting. That is
> where the problem lies.
>
> >>>>>> Rarely, and no one worries about it today. As I mentioned,
> >>>>>> cars had the problem with dimpled steering gears. I worked on
> >>>>>> them as a child in grade school. We had it on Fords and
> >>>>>> Chevrolets.
> >>>>> So was that caused by flexible components?
> With what part of fretting did is disagree?
>
> How do you remove the problem of flexing in the steertube. I see not
> way around that although making a bearing that is not affected by it
> has been demonstrated.
There is no problem. Precisely the steerer flexes and the cone
bearing accomodates this.
Jobst Brandt
>>>>> the perfect time to write:
>>>>>> Fork blades are stiffer than the steertube in the fore and aft
>>>>>> direction. Just inspect the dimension in that direction and
>>>>>> that there are two fork blades... on purpose.
>>>>> Maybe you should compare the dimensions of the traditional
>>>>> tapered and curved fork blade with that of the steerer.
>>>> Oh! You believe the curl in the fork is to absorb road shock.
>>>> That part of the fork does not flex measurably. Its job is to
>>>> set steering trail, as you may have noticed with todays (ugly)
>>>> straight blade forks that are angled from the fork crown to
>>>> achieve trail with respect to the steertube axis.
>>> You can test it if you like - just by fitting a wire between the
>>> front axle and steering head and observing that it slackens
>>> briefly over bumps.
>> You'd need to attach it between the eyelet at the rear of the
>> dropout and the brake bolt to see whether the fork articulates.
>> Running it up to the top of the steertube would include steertube
>> flex. Suspension flex is not generated in the fork blades.
> The ones I've checked have had eyelets at the front of the dropout
> as well, so you can run the wire from there to the brake-bolt hole
> in the fork crown.
> The flexing of the fork legs becomes particularly noticeable if you
> fit a front rack, when you will find that if the attachments to
> dropout and fork crown are both rigid, and the rack is fully
> triangulated, the ride will become harsh and the rack prone to
> cracking at the attachments.
So how do you explain that the current straight fork blades that have
a substantially greater bending stiffness (in-line direction) than
typical tubular curled forks that ride the same. I think you should
look at the straightness of your wire to see it slacken when you put a
load on the front wheel, the direction of typical fork loading.
>>>>> You can then try to make an engineering case of how two very
>>>>> small diameter tubes are stiffer than one tube of more than
>>>>> twice the diameter. Good luck with that.
It depends on how far from a possible bending fulcrum and load
application you are looking. This is opposite from braking loads
which would cause tensioning in the test wire if there was a
significant change in fork alignment.
>> I think you may have to make some measurements to assure yourself
>> of your error.
> It was by making the measurements that I assured myself of yours!
This is an old subject that has been beat3en to death here on
wreck.bike. You are trying hard to breathe new life into this fable
of suspension elasticity of the fork curl. The one that went away fr
many new bicycles.
>>>> Don't move! You are standing in deep shit. The fork blades are
>>>> not flexing suspension elements. That job is done by pneumatic
>>>> tires and top & downtube flex of the frame. I hope you noticed
>>>> what gets bent when a bicycle is ridden into a wall. On the
>>>> other hand, we have seen plenty of pictures of squirrels in front
>>>> wheels that break the fork off at the crown, not at the thin end
>>>> near the dropouts.
>>> Of course they do - that's where they hit it!
The damage comes from front wheel lock-up and bending, not from the
body of a squishy rodent striking the fork like a hammer. A tightly
rolled up newspaper would do the same thing. It's not impact that
breaks the fork, but rather bending moment similar to running into a
wall.
>> I think any frame builder can clear you up on your misconception.
> Well, if your assertion is correct, the material and shape of the
> fork blades can have no impact on comfort or handling. As long as
> it is not substantially softer than the steertube.
> I don't know of any frame builder who would agree with that
> assertion.
I don't believe you know ANY frame builders.
Jobst Brandt
Jobst Brandt
>>> I think any frame builder can clear you up on your misconception.
>> Well, if your assertion is correct, the material and shape of the
>> fork blades can have no impact on comfort or handling.
>> I don't know of any frame builder who would agree with that
>> assertion.
> Nor any rider who has changed to a different gauge. There I am at
> 13st still riding hard (occassionally) on SL blades because they are
> comfortable and help maintain road contact.
And why would anyone choose to a different gauge, there being no
palpable spring action in fork blades.
Jobst Brandt
thirty-six
Stop being an ignoramus. The difference is easily felt between
forks, if one wishes to make a direct comparison, by dropping off a 4"
kerbstone, for instance. The difference can be easily felt by me not
having a bruise on my arse after I didn't drop trhe bike on that rough
corner.
thirty-six
I can see it ticking, but you have not performed the test. Observe
the action, stop making suppositions.
I can put my hand on three within 1/2 hour of walking (not very
sociable at this time though). Fork blade material and guage
selection is possibly the most important criteria for influencing the
feel and control of a bike (after the wheels). The main frame needs
to be up to the job, the saddle and rear wheel providing the necessary
suspension.
>
> Jobst Brandt
Jobst Brandt
>> The title is "Rolling Bearing Analysis" by Tedric Harris. What is
>> it you think makes Mr. Harris' tome invalid for analyzing ball
>> bearings?
> Irrelevant. The discussion is specific to bicycle headsets, not
> covered by Harris.
How does the ball bearing know to what sort of use it it is being used
other than to bear rotation loads and associated movement? Therefore,
Mr. Harris is treating the general problem of fretting damage in
general.
>>> The fact that you continue to disregard the lubrication
>>> specification with environment as part of the service requirement
>>> of the component indicates your low level of understanding of the
>>> subject. Correct lubrication leads to long life bearings.
>> That you ignore what grease is, is in itself an indication that you
>> don't understand lubrication or the whole field of tribology.
> Personal again. I have a sufficient understanding of lubrication
> mediums and their suitability of application. I am not here to
> claim I've a bigger head than you.
I think you should then know that grease is oil suspended in a gelled
medium called "soap" in grease parlance.
>>>>> 'Fretting damage' as you refer it on a ball bearing headset does
>>>>> NOT occur when the headset is correctly lubricated. It never
>>>>> has. Damage only occurs when the incorrect lubricant for the
>>>>> bearing design is used.
I think you should take that up with Shimano, Cane Creek, SKF, and
New-Departure among others. They all recognize this as a serious
problem. For which there is no mitigation from choice of lubricant.
>> Please stop generating your own idea of bearing wear. You have no
>> idea of what occurs in lubricated rolling bearings. Where did you
>> get these ideas? It wasn't in mechanical engineering school.
You can read about his in any bearing application in books and on the
WWW. If you don't read technical treatises, they you might imagine
that I initiated the concept, but there are many who teach the subject
who publish these effects.
> The learning of suitability or not of lubricants for headsets came
> directly from me using bicycles and changing lubricants. Castrol LM
> was possibly the worst performer.
You should be able to find published and peer reviewed work on the
subject rather than fall back on, what appears to be misinterpreted
observation.
>>> Stop trying. Ancient headset bearings are also angular contact
>>> (pre- loaded if you like). They work fine with the correct
>>> lubricant for the service conditions.
They never "worked fine" and the problem of dimples head bearings is
an old one.
>> They are not pre-loaded angular contact cartridge ball bearings,
> Then you've been doing it wrong.
>> but ball bearings whose clearance is adjusted to near zero at the
>> outset,
The preload in these angular contact cartridge bearings is there to
enable the bearings to transmit rocking motion to the spherical plain
bearing on which it sits. Why don't you visit your bike shop and ask
to inspect a classic Shimano cartridge head bearing and notice that it
cannot be disassembled by hand.
> You should nip up from that, it's what you get when you pay an
> experienced bicycle mechanic.
What do you mean with that remark?
>> but developing fretting dimples give them the undesirable backlash
>> while riding. If that clearance is adjusted away, the bearing
>> locks into the dimples giving an indexed steering that homes as
>> bearing balls drop into dimples during steering motions.
> You know that bit you had to adjust to remove the play, that's the
> amount you should have nipped up on your replacement.
The play is in the dimples that were generated, not in initial bearing
adjustment. How do you explain that?
>>>>>> You might look into that before offering your lubrication
>>>>>> excuse again.
>>>>> No excuses, the only headset bearing failures I had were when
>>>>> using auto wheel grease for lubrication. When I returned to
>>>>> oil, there were no failures, when I changed to a soft calcium
>>>>> grease there were no failures. Even a 'Cycle grease' gave a
>>>>> much improved lifespan than auto wheel bearing grease.
An amazing coincidence. I can imagine that your test for proper
adjustment was inaccurate. What was the result? Did you have dimples
in the races and where were they located? I suspect they were in the
forward and rearward quadrant (in direction of travel) of the races.
>> Oh! Now it seems to be the grease that is too hard and needs to be
>> "soft".
> Yes the grease requires a viscocity of low levels for it is not
> drawn on to the balls in the same way as a wheel bearing is.
That seems mysterious to me because grease is in effect made of
oil. and it is the oil that lubricates.
>>>> Just think how much cost you could have saved the bicycle
>>>> industry if you had revealed and instructed on how to prevent
>>> OFD COURSE YOU DONT!!
>>>>>>> LIES!
Judging from the tenor of this thread, engineering the UK operates on
a different physics than elsewhere. Both Phil Lee and Trevor Jeffry,
from the UK, seem to have learned from the same teachers of
unconventional tribology... and writing.
Jobst Brandt
Jobst Brandt
>>>> I think you may have to make some measurements to assure yourself
>>>> of your error.
>>> It was by making the measurements that I assured myself of yours!
>> This is an old subject that has been beaten to death here on
>> wreck.bike. You are trying hard to breathe new life into this
>> fable of suspension elasticity of the fork curl. The one that went
>> away for many new bicycles with no curl in the fork
I hope you noticed while visiting these frame builders, that their
forks blades come with no curl and that the curl is added by the frame
maker to give suitable trail for the steer tube angle selected.
That's why track bicycles with steeper head angles have almost no
curl.
Jobst Brandt
thirty-six
No, I dont think they did. I think they are supplied ready shaped,
there being no reason to deviate.
> and that the curl is added by the frame
> maker to give suitable trail for the steer tube angle selected.
Erm, no, they cut the tube to length and install the fork ends to get
the correct rake. The crown end is then cut to length.
>
> That's why track bicycles with steeper head angles have almost no
> curl.
OH, you are trying to say what exactly? We've been through this,
there is little difference between a modern criterium bike and a
pursuit bike. You simply cannot just move rider weight forward for
he will lose the rear of the bike. The way to go is to have a deep
handlebar position for a sprinter or points race.
>
> Jobst Brandt
Jobst Brandt
I see, even frame building is different in GB than elsewhere. I
watched Cinelli (S. Valsassina), and the man at Masi bend the curl
into originally straight fork blades and all the local builders do
that as well. That's too bad. It seems to generate another
perspective on forks that is not reconcilable.
Jobst Brandt
Jobst Brandt
thirty-six
> Trevor Jeffrey wrote:
> >> The title is "Rolling Bearing Analysis" by Tedric Harris. What is
> >> it you think makes Mr. Harris' tome invalid for analyzing ball
> >> bearings?
> > Irrelevant. The discussion is specific to bicycle headsets, not
> > covered by Harris.
>
> How does the ball bearing know to what sort of use it it is being used
> other than to bear rotation loads and associated movement?
> Therefore,
> Mr. Harris is treating the general problem of fretting damage in
> general.
Yes, NOT specific to cone style cycle bearings with a dominant axial
load and oscillatory radial component of shock loading.
>
> >>> The fact that you continue to disregard the lubrication
> >>> specification with environment as part of the service requirement
> >>> of the component indicates your low level of understanding of the
> >>> subject. Correct lubrication leads to long life bearings.
> >> That you ignore what grease is, is in itself an indication that you
> >> don't understand lubrication or the whole field of tribology.
> > Personal again. I have a sufficient understanding of lubrication
> > mediums and their suitability of application. I am not here to
> > claim I've a bigger head than you.
>
> I think you should then know that grease is oil suspended in a gelled
> medium called "soap" in grease parlance.
>
> >>>>> 'Fretting damage' as you refer it on a ball bearing headset does
> >>>>> NOT occur when the headset is correctly lubricated. It never
> >>>>> has. Damage only occurs when the incorrect lubricant for the
> >>>>> bearing design is used.
>
> I think you should take that up with Shimano, Cane Creek, SKF, and
> New-Departure among others. They all recognize this as a
marketing opportunity.
> serious
> problem. For which there is no mitigation from choice of lubricant.
MARKETTING!
>
> >> Please stop generating your own idea of bearing wear. You have no
> >> idea of what occurs in lubricated rolling bearings. Where did you
> >> get these ideas? It wasn't in mechanical engineering school.
>
> You can read about his in any bearing application in books
Yes I remember now, that's where I got it, from BOOKS, not one single
reference over fifty years old.
> and on the
> WWW. If you don't read technical treatises, they you might imagine
> that I initiated the concept, but there are many who teach the subject
> who publish these effects.
On bicycle headsets? SHOW ME!
>
> > The learning of suitability or not of lubricants for headsets came
> > directly from me using bicycles and changing lubricants. Castrol LM
> > was possibly the worst performer.
>
> You should be able to find published and peer reviewed work on the
> subject rather than fall back on, what appears to be misinterpreted
> observation.
Best performing lubricant does not lead to any problems with headset
however you may wish to misinterpret my results.
>
> >>> Stop trying. Ancient headset bearings are also angular contact
> >>> (pre- loaded if you like). They work fine with the correct
> >>> lubricant for the service conditions.
>
> They never "worked fine" and the problem of dimples head bearings is
> an old one.
Only for those which did not have an adequate lubrication service
interval. In other words, bikes not maintained. It may be worth you
considering that even those cycles that were toys, they were never
considered as just toys in the UK and bicycles and tricycles were
considered to be of value and were considered worthy of a litttle
attention.
>
> >> They are not pre-loaded angular contact cartridge ball bearings,
> > Then you've been doing it wrong.
> >> but ball bearings whose clearance is adjusted to near zero at the
> >> outset,
>
> The preload in these angular contact cartridge bearings is there to
> enable the bearings to transmit rocking motion
In an attempt to emulate a cone cycle bearing, how CLEVER.
> to the spherical plain
> bearing on which it sits. Why don't you visit your bike shop and ask
> to inspect a classic Shimano cartridge head bearing and notice that it
> cannot be disassembled by hand.
Pointless.
>
> > You should nip up from that, it's what you get when you pay an
> > experienced bicycle mechanic.
>
> What do you mean with that remark?
What I said..
>
> >> but developing fretting dimples give them the undesirable backlash
> >> while riding. If that clearance is adjusted away, the bearing
> >> locks into the dimples giving an indexed steering that homes as
> >> bearing balls drop into dimples during steering motions.
> > You know that bit you had to adjust to remove the play, that's the
> > amount you should have nipped up on your replacement.
>
> The play is in the dimples that were generated, not in initial bearing
> adjustment. How do you explain that?
You're a fool for continuing with the same method that only gives you
fifty miles of riding.
>
> >>>>>> You might look into that before offering your lubrication
> >>>>>> excuse again.
> >>>>> No excuses, the only headset bearing failures I had were when
> >>>>> using auto wheel grease for lubrication. When I returned to
> >>>>> oil, there were no failures, when I changed to a soft calcium
> >>>>> grease there were no failures. Even a 'Cycle grease' gave a
> >>>>> much improved lifespan than auto wheel bearing grease.
>
> An amazing coincidence. I can imagine that your test for proper
> adjustment was inaccurate. What was the result?
Adjustment was good.
> Did you have dimples
> in the races and where were they located? I suspect they were in the
> forward and rearward quadrant (in direction of travel) of the races.
What? I do not have any headsets dimpled. In the past I have had
headsets with corrosion and wear pits. Dimpling is caused by an
overload which cannot exist with a correctly adjusted headset without
frame (and rider) damage occuring. As I said you've been doing it
wrong.
>
> >> Oh! Now it seems to be the grease that is too hard and needs to be
> >> "soft".
> > Yes the grease requires a viscocity of low levels for it is not
> > drawn on to the balls in the same way as a wheel bearing is.
>
> That seems mysterious to me
You lack of understanding is becoming all the more clear to me.
You need to examine and observe a MOVING bearing before you can see
the flow of grease. This is NOT observable from a book. This is best
observed in real time and the observer can alter the speed and
temperature of the bearing in question. With a reasonable viscosity,
ripples and waves will form in the grease as pressure differences
surrounding the elements become evident.
> because grease is in effect made of
> oil. and it is the oil that lubricates.
*****
YOU. There, what a surprise.
elsewhere. Both Phil Lee and Trevor Jeffry,
> from the UK, seem to have learned from the same teachers of
> unconventional tribology... and writing.
It is quite obvious that Mr Lee and I have a more complete
understanding of lubrication theory and application than yourself.
I'll repeat, lubricant selection is specific to environment. This
could suggest that an appropriate grease on a cycle in the summer is
inappropriate for the winter. Using an NLGI2 lithium wheel bearing
grease will do nothing to prevent wear of a headset in sub freezing
temperatures.
>
> Jobst Brandt
thirty-six
Do they really, all with there own forming jig and bender?
Practicallity means that small builders do not need to invest in such
equipment and may rely opon their supplier to make a consistent curve
and fork response.
AMuzi
Frame repair shops buy both straight and curved steel fork
blades for various applications. Both are common and cost
the same, straight being the majority. Some builders feel a
distinctive radius says 'my work'. If one is building a lot
of the same thing, building with straight blades (curved
after building) is slightly faster. Any differences are
small and in the realm of personal taste.
Jobst Brandt
>>>> The title is "Rolling Bearing Analysis" by Tedric Harris. What is
>>>> it you think makes Mr. Harris' tome invalid for analyzing ball
>>>> bearings?
>>> Irrelevant. The discussion is specific to bicycle headsets, not
>>> covered by Harris.
>> How does the ball bearing know to what sort of use it it is being used
>> other than to bear rotation loads and associated movement?
>> Therefore, Mr. Harris is treating the problem of fretting in
>> general.
> Yes, NOT specific to cone style cycle bearings with a dominant axial
> load and oscillatory radial component of shock loading.
>>>>> The fact that you continue to disregard the lubrication
>>>>> specification with environment as part of the service
>>>>> requirement of the component indicates your low level of
>>>>> understanding of the subject. Correct lubrication leads to long
>>>>> life bearings.
>>>> That you ignore what grease is, is in itself an indication that
>>>> you don't understand lubrication or the whole field of tribology.
>>> Personal again. I have a sufficient understanding of lubrication
>>> mediums and their suitability of application. I am not here to
>>> claim I've a bigger head than you.
>> I think you should then know that grease is oil suspended in a
>> gelled medium called "soap" in grease parlance.
>>>>>>> 'Fretting damage' as you refer it on a ball bearing headset
>>>>>>> does NOT occur when the headset is correctly lubricated. It
>>>>>>> never has. Damage only occurs when the incorrect lubricant
>>>>>>> for the bearing design is used serious problem. For which
>>>>>>> there is no mitigation from choice of lubricant.
> MARKETTING!
To call all these engineering efforts "MARKETING" is rude, especially
when they have achieved improvement.
>>>> Please stop generating your own idea of bearing wear. You have
>>>> no idea of what occurs in lubricated rolling bearings. Where did
>>>> you get these ideas? It wasn't in mechanical engineering school.
>> You can read about his in any bearing application in books
>> and on the WWW. If you don't read technical treatises, they you
>> might imagine that I initiated the concept, but there are many who
>> teach the subject who publish these effects.
> On bicycle headsets? SHOW ME!
On bearings. What is so specific about bicycle bearings that it takes
a separate field of technology?
> Yes I remember now, that's where I got it, from BOOKS, not one single
> reference over fifty years old.
I doubt that you read "Rolling Bearing Analysis" that is more than 50
years old.
>>> The learning of suitability or not of lubricants for headsets came
>>> directly from me using bicycles and changing lubricants. Castrol LM
>>> was possibly the worst performer.
>> You should be able to find published and peer reviewed work on the
>> subject rather than fall back on, what appears to be misinterpreted
>> observation.
> Best performing lubricant does not lead to any problems with headset
> however you may wish to misinterpret my results.
>>>>> Stop trying. Ancient headset bearings are also angular contact
>>>>> (pre- loaded if you like). They work fine with the correct
>>>>> lubricant for the service conditions.
>> They never "worked fine" and the problem of dimpled head bearings is
>> an old one.
> Only for those which did not have an adequate lubrication service
> interval. In other words, bikes not maintained. It may be worth you
> considering that even those cycles that were toys, they were never
> considered as just toys in the UK and bicycles and tricycles were
> considered to be of value and were considered worthy of a litttle
> attention.
With all you emphasis on proper lubrication, it must have dawned on
some bearing or lubrication scientist, but I see no mention of it in
the literature. I think you stand alone in your religious belief.
>>>> They are not pre-loaded angular contact cartridge ball bearings,
>>> Then you've been doing it wrong.
>>>> but ball bearings whose clearance is adjusted to near zero at the
>>>> outset,
>> The preload in these angular contact cartridge bearings is there to
>> enable the bearings to transmit rocking motion to the spherical
>> plain bearing on which it sits. Why don't you visit your bike shop
>> and ask to inspect a classic Shimano cartridge head bearing and
>> notice that it cannot be disassembled by hand.
> In an attempt to emulate a cone cycle bearing, how CLEVER.
Cup and cone bicycle head bearings freely rock crosswise to the
direction of steering rotation. That is fretting. Of course you must
have noticed that if you worked on head bearings.
> Pointless.
>>> You should nip up from that, it's what you get when you pay an
>>> experienced bicycle mechanic.
>> What do you mean with that remark?
> What I said..
What you write and the English language are a distance apart in
vocabulary and spelling.
>>>> but developing fretting dimples give them the undesirable
>>>> backlash while riding. If that clearance is adjusted away, the
>>>> bearing locks into the dimples giving an indexed steering that
>>>> homes as bearing balls drop into dimples during steering motions.
>>> You know that bit you had to adjust to remove the play, that's the
>>> amount you should have nipped up on your replacement.
>>
>> The play is in the dimples that were generated, not in initial bearing
>> adjustment. How do you explain that?
> You're a fool for continuing with the same method that only gives
> you fifty miles of riding.
Could you present your beliefs without the name calling.
>>>>>>>> You might look into that before offering your lubrication
>>>>>>>> excuse again.
>>>>>>> No excuses, the only headset bearing failures I had were when
>>>>>>> using auto wheel grease for lubrication. When I returned to
>>>>>>> oil, there were no failures, when I changed to a soft calcium
>>>>>>> grease there were no failures. Even a 'Cycle grease' gave a
>>>>>>> much improved lifespan than auto wheel bearing grease.
>> An amazing coincidence. I can imagine that your test for proper
>> adjustment was inaccurate. What was the result?
> Adjustment was good.
>> Did you have dimples in the races and where were they located? I
>> suspect they were in the forward and rearward quadrant (in
>> direction of travel) of the races.
> What? I do not have any headsets dimpled. In the past I have had
> headsets with corrosion and wear pits. Dimpling is caused by an
> overload which cannot exist with a correctly adjusted headset
> without frame (and rider) damage occuring. As I said you've been
> doing it wrong.
Corrosion is a dodge around the word fretting. After fretting has
penetrated bearing lubrication, rust can readily follow. It is not the
cause of the damage but an after effect.
>>>> Oh! Now it seems to be the grease that is too hard and needs to be
>>>> "soft".
>>> Yes the grease requires a viscocity of low levels for it is not
>>> drawn on to the balls in the same way as a wheel bearing is.
>> That seems mysterious to me
> You lack of understanding is becoming all the more clear to me. You
> need to examine and observe a MOVING bearing before you can see the
> flow of grease. This is NOT observable from a book. This is best
> observed in real time and the observer can alter the speed and
> temperature of the bearing in question. With a reasonable
> viscosity, ripples and waves will form in the grease as pressure
> differences surrounding the elements become evident.
Flow-back is not then mechanism for re-lubricating an area that has
displaced lubrication by fretting. Ball and roller movement is the
means that replenishes lubricant, but in a fretting mode, there isn't
enough rotation to do that.
> *****
>>>>> OFD COURSE YOU DONT!!
>>>>>>>>> LIES!
>>>> so to speak.
>>> to inappropriate tension put on the steerer tube as well as the
>>> unsuitable selection of grease.
>>>>>> What characteristic of wheel bearing grease is it that causes
>>>>>> this effect?
>>>>> It does not lubricate an extreme pressure ocillatory bearing
>>>>> because it is not designed for that. Wheel bearing grease is
>>>>> meant to be heated by the continuous rolling of the bearing,
>>>>> something that cannot occur with a bicycle headset. It is an
>>>>> innapropriate lubricant for bicycles in general, but is
>>>>> espscially poor for headsets.
>>>> I think you made that up right now. What heats the grease other
>>>> than braking? On long steady highways the bearings do not get
>>>> warm.
>>> Yes they do. Use an infra-red thermometer on aq cloudy day and
>>> you can see the temperature rise with ease.
>> Judging from the tenor of this thread, engineering the UK operates
>> on a different physics than elsewhere. Both Phil Lee and Trevor
>> Jeffry, from the UK, seem to have learned from the same teachers of
>> unconventional tribology... and writing.
> YOU. There, what a surprise.
> It is quite obvious that Mr Lee and I have a more complete
> understanding of lubrication theory and application than yourself.
You stand too much alone to declare competence on the subject.
> I'll repeat, lubricant selection is specific to environment. This
> could suggest that an appropriate grease on a cycle in the summer is
> inappropriate for the winter. Using an NLGI2 lithium wheel bearing
> grease will do nothing to prevent wear of a headset in sub freezing
> temperatures.
Fretting failures have occurred mainly in the heavy riding season, the
sumer and lithium white grease from Campagnolo is famous for becoming
stiff tar.
Jobst Brandt
Jobst Brandt
That shows ho little you know about the subject. A frame builder has
a form of curved wood with a pair of hooks at the end of the curl into
which the brazed fork is hooked and bent holding the steertube. The
fixture has either a stop at the appropriate place of the builder is
making a one-off and lays the fork on a gauge on a plane table to
asses whether the curl is right.
Tom Sherman °_°
> [...]
> Jester.[...]
<http://www.ligfietswinkel.nl/images/stories/ligfiets/challenge_jester_diamond_violet.jpg>
--
Tom Sherman - 42.435731,-83.985007
I am a vehicular cyclist.
Tom Sherman °_°
> [...]
> forks, if one wishes to make a direct comparison, by dropping off a 4"
Trevor dropping a 4-inch kerbstone on his head explains a lot. ;)
Tom Sherman °_°
> [...]
> Don't move! You are standing in deep shit. The fork blades are not
> flexing suspension elements. That job is done by pneumatic tires and
> when a bicycle is ridden into a wall. On the other hand, we have seen
> plenty of pictures of squirrels in front wheels that break the fork
> off at the crown, not at the thin end near the dropouts.
>
the frame on a Peugeot P-8 during a collision with an errant pedestrian.
Probably cannot verify it at this date, unless Mr. Muzi keeps 27+ year
old repair tickets around.
AMuzi
Sorry, Tom we don't. And I can't actually recall it, bent
forks here being much like milk in a grocery.
Tom Sherman °_°
Do you see many bikes with bent forks, but no frame damage?
thirty-six
wrote:
> On 10/12/2010 4:35 PM, thirty-six aka Trevor Jeffrey wrote:
>
> > [...]
> > Jester.[...]
>
Damn, that looks good. Anything with a rider on it?
Tom Sherman °_°
thirty-six
> Trevor Jeffrey wrote:
> > MARKETTING!
>
> To call all these engineering efforts "MARKETING" is rude, especially
> when they have achieved improvement.
Onlyt for those who will not perform a lubrication service on their
machine(s).
> > On bicycle headsets? SHOW ME!
>
> On bearings. What is so specific about bicycle bearings that it takes
> a separate field of technology?
It certainly is not a difficult request to fulfill, surely?
> With all you emphasis on proper lubrication, it must have dawned on
> some bearing or lubrication scientist, but I see no mention of it in
> the literature. I think you stand alone in your religious belief.
Ass.
> > In an attempt to emulate a cone cycle bearing, how CLEVER.
>
> Cup and cone bicycle head bearings freely rock crosswise to the
> direction of steering rotation. That is fretting.
That is the normal service condition which does not cause problems
when correctly lubricated.
> Of course you must
> have noticed that if you worked on head bearings.
>
> > Pointless.
> >>> You should nip up from that, it's what you get when you pay an
> >>> experienced bicycle mechanic.
> >> What do you mean with that remark?
> > What I said..
>
> What you write and the English language are a distance apart in
> vocabulary and spelling.
A recognised experienced bicycle mechanic will perform a better job
than you of setting the correct tension on the steer tube.
>
> >> The play is in the dimples that were generated, not in initial bearing
> >> adjustment. How do you explain that?
> > You're a fool for continuing with the same method that only gives
> > you fifty miles of riding.
>
> Could you present your beliefs without the name calling.
Of course you think you are correct and the ancients knew not what
they were doing. Have a little thought, that cone bearing headset
design was designed around a different lubricant than which you wish
to force upon it. There is nothing wrong with the design and
everything right, it's just that you do not understand that different
lubricant formats have significantly different properties. If you
wish to use a heavy grease lubricant for ten continyuous years then
the design is defunct and a more complex and expensive fitment is
'required'.
>
> > What? I do not have any headsets dimpled. In the past I have had
> > headsets with corrosion and wear pits. Dimpling is caused by an
> > overload which cannot exist with a correctly adjusted headset
> > without frame (and rider) damage occuring. As I said you've been
> > doing it wrong.
>
> Corrosion is a dodge around the word fretting.
Your terminology is vague. There are three recognised failure modes,
fatigue, corrosion and wear. Why do ypou insist on being so vague and
object to my distinction?
> After fretting has
> penetrated bearing lubrication, rust can readily follow. It is not the
> cause of the damage but an after effect.
Ah I see you have it a/t again, that's why.
>
> >>>> Oh! Now it seems to be the grease that is too hard and needs to be
> >>>> "soft".
> >>> Yes the grease requires a viscocity of low levels for it is not
> >>> drawn on to the balls in the same way as a wheel bearing is.
> >> That seems mysterious to me
> > You lack of understanding is becoming all the more clear to me. You
> > need to examine and observe a MOVING bearing before you can see the
> > flow of grease. This is NOT observable from a book. This is best
> > observed in real time and the observer can alter the speed and
> > temperature of the bearing in question. With a reasonable
> > viscosity, ripples and waves will form in the grease as pressure
> > differences surrounding the elements become evident.
>
> Flow-back is not then mechanism for re-lubricating an area that has
Aunt Kitty doesn't have raw chicken for breakfast, cod is £13 a kilo.
> displaced lubrication by fretting. Ball and roller movement is the
> means that replenishes lubricant, but in a fretting mode, there isn't
> enough rotation to do that.
Then you are USING the WRONG LUBRICANT.
>
> > YOU. There, what a surprise.
> > It is quite obvious that Mr Lee and I have a more complete
> > understanding of lubrication theory and application than yourself.
>
> You stand too much alone to declare competence on the subject.
You are the one unable to lubricate a cone heaset effectively. I have
no problems with them.
>
> > I'll repeat, lubricant selection is specific to environment. This
> > could suggest that an appropriate grease on a cycle in the summer is
> > inappropriate for the winter. Using an NLGI2 lithium wheel bearing
> > grease will do nothing to prevent wear of a headset in sub freezing
> > temperatures.
>
> Fretting failures have occurred mainly in the heavy riding season, the
> sumer and lithium white grease from Campagnolo is famous for becoming
> stiff tar.
More like you failed to give an annual regrease and you left your bike
standing in the sun when you rested. The stiffening of the grease
should have you on your toes to replace it, but of course 'engineer'
Brandt has a point to prove. I've had my fill with you, you really
are an ass.
thirty-six
wrote:
> On 10/12/2010 11:06 PM, thirty-six aka Trevor Jeffrey wrote:
>
> > On 13 Oct, 04:19, Tom Sherman °_°<twshermanREM...@THISsouthslope.net>
> > wrote:
> >> On 10/12/2010 4:35 PM, thirty-six aka Trevor Jeffrey wrote:
>
> >>> [...]
> >>> Jester.[...]
>
> >> <http://www.ligfietswinkel.nl/images/stories/ligfiets/challenge_jester...>
>
> > Damn, that looks good. Anything with a rider on it?
>
> <http://www.recumbents.com/wisil/racing2006/xenia/cortez/Dscf1621.jpg>
>
HE's a spoiler. I do prefer the purple rims, in fact maybe recumbents
MUST have coloured wheels.
Tom Sherman °_°
> [...]
<http://www.billybear4kids.com/animal/whose-toes/AsianWildAss.jpg>.
thirty-six
wrote:
> On 10/12/2010 11:39 PM, thirty-six aka Trevor Jeffrey wrote:
>
> > [...]
> > Ass.[...]
>
> <http://www.billybear4kids.com/animal/whose-toes/AsianWildAss.jpg>.
>
Yep, but I pprobably mean mule.
thirty-six
As in stuborn as a . .
But I really did mean I think he is an ass, just probably not in the
way some connotations are made to the term, but then I'm not fretting.
Jobst Brandt
>>> MARKETTING!
> Ass.
>>> Pointless.
>>> What I said..
I see you think steertube tension is important, but bearing clearance
is primary in steering precision and lack of chatter that shows up
with bearing fretting.
>>>>>> The play is in the dimples that were generated, not in initial
>>>>>> bearing adjustment. How do you explain that?
>>> You're a fool for continuing with the same method that only gives
>>> you fifty miles of riding.
>> Could you present your beliefs without the name calling.
> Of course you think you are correct and the ancients knew not what
> they were doing. Have a little thought, that cone bearing headset
> design was designed around a different lubricant than which you wish
> to force upon it. There is nothing wrong with the design and
> everything right, it's just that you do not understand that different
> lubricant formats have significantly different properties. If you
> wish to use a heavy grease lubricant for ten continyuous years then
> the design is defunct and a more complex and expensive fitment is
> 'required'.
Your lubricant fetish seems to have overcome any ability to recognize
frictional wear in rolling bearings. As I said, you ought to read
"Rolling Bearing Analysis" and the bio of Tedric Harris, a clear
thinking mechanical engineer with good peer review.
>>> What? I do not have any headsets dimpled. In the past I have had
>>> headsets with corrosion and wear pits. Dimpling is caused by an
>>> overload which cannot exist with a correctly adjusted headset
>>> without frame (and rider) damage occuring. As I said you've been
>>> doing it wrong.
That assessment goes against what has been researched and discovered
by manufacturers in products. Once more. you might have a close look
at Crane Creek and Shimano head bearings so you understand how it is
done after all these years of dimpled head bearings.
I am surprised that you didn't bring up the belief that dimples in
head bearings are Brinell indentations cause by road impact coming up
through the pneumatic tire, as so many hammer blows. That was the
line of argumentation the last time head bearing dimples were
discussed by the faithful in this newsgroup.
>> Corrosion is a dodge around the word fretting.
> Your terminology is vague. There are three recognised failure modes,
> fatigue, corrosion and wear. Why do ypou insist on being so vague and
> object to my distinction?
Corrosion sets in after the lubricant has been displaced by fretting
and bare steel with micro-texture is exposed to humid air.
>> After fretting has penetrated bearing lubrication, rust can readily
>> follow. It is not the cause of the damage but a result of it.
> Ah I see you have it a/t again, that's why.
Please be more precise. What is it I am "at" again?
>>>>>> Oh! Now it seems to be the grease that is too hard and needs
>>>>>> to be "soft".
>>>>> Yes the grease requires a viscocity of low levels for it is not
>>>>> drawn on to the balls in the same way as a wheel bearing is.
>>>> That seems mysterious to me.
>>> You lack of understanding is becoming all the more clear to
>>> me. You need to examine and observe a MOVING bearing before you
>>> can see the flow of grease. This is NOT observable from a
>>> book. This is best observed in real time and the observer can
>>> alter the speed and temperature of the bearing in question. With
>>> a reasonable viscosity, ripples and waves will form in the grease
>>> as pressure differences surrounding the elements become evident.
>> Flow-back is not then mechanism for re-lubricating an area that has
>> displaced lubrication by fretting. Ball and roller movement is the
>> means that replenishes lubricant, but in a fretting mode, there
>> isn't enough rotation to do that.
> Then you are USING the WRONG LUBRICANT.
> Aunt Kitty doesn't have raw chicken for breakfast, cod is £13 a kilo.
I suppose you think this comment adds humor to a dry subject. It
doesn't and is an analogy unknown to most readers of this newsgroup.
>>> YOU. There, what a surprise. It is quite obvious that Mr Lee and
>>> I have a more complete understanding of lubrication theory and
>>> application than yourself.
>> You stand too much alone to declare competence on the subject.
> You are the one unable to lubricate a cone heaset effectively. I
> have no problems with them.
Delving into analogies, let me say that I have been warned that
engaging in an exchange with you or Mr. Lee is like Tar Baby:
======================================================================
The Tar-Baby is a doll made of tar and turpentine used to entrap Br'er
Rabbit in the second of the Uncle Remus stories. The more that Br'er
Rabbit fights the Tar-Baby, the more entangled he becomes. In modern
usage, "tar baby" refers to any "sticky situation" that is only
aggravated by additional contact. The only way to solve such a
situation is by separation.
======================================================================
>>> I'll repeat, lubricant selection is specific to environment. This
>>> could suggest that an appropriate grease on a cycle in the summer
>>> is inappropriate for the winter. Using an NLGI2 lithium wheel
>>> bearing grease will do nothing to prevent wear of a headset in sub
>>> freezing temperatures.
>> Fretting failures have occurred mainly in the heavy riding season,
>> the sumer and lithium white grease from Campagnolo is famous for
>> becoming stiff tar.
> More like you failed to give an annual regrease and you left your bike
> standing in the sun when you rested. The stiffening of the grease
> should have you on your toes to replace it, but of course 'engineer'
> Brandt has a point to prove. I've had my fill with you, you really
> are an ass.
Thanks for the kind words. I see you have run out of false mechanical
arguments and are reverting to name calling.
Jobst Brandt
Jobst Brandt
the classic misunderstanding of mechanical failures in bicycles so
they can be brought to the surface in this forum. One could say: "I
thought you'd nver ask!"... but they have all come to the surface
through th\ e repetition of "common knowledge" by Trevor (&Lee)xy
Jobst Brandt
AMuzi
stronger forks so both are more likely damaged.
But the range is wide and these are trends not absolutes. In
similar crashes one might see zero to severe rider injury
with OK or dead wheels or forks or frames and all
combinations thereof. It's in the realm of dynamics so a
simple static analysis doesn't help.
Jobst Brandt
>>>>> I think the Vincent had taper rollers as standard - I'd be very
>>>>> surprised if any of the others did, although some Ariel's had
>>>>> them if they were specified for sidecar use (those models were
>>>>> beefed up all round)
>>>>>>>> Get a motorcycle fork for your bicycle if you think that will
>>>>>>>> make your bicycle lighter and more durable.
>>>>>>> Just avoiding stupid light steerers and using taper rollers is
>>>>>>> sufficient.
>>>>>> As you see, there is a solution and that is to not use rigidly
>>>>>> positioned ball bearing races while sticking with current fork
>>>>>> weight, even if it is threadless.
>>>>>>>>> Maybe you also think that fitting flexible axles to railway
>>>>>>>>> vehicles would improve the suspension? Same principle.
>>>>>> What does that have to do with head bearings and their design?
>>>>>> I see no parallel in the principle because RR trucks don't
>>>>>> mount on steertubes and don't have rolling bearings for
>>>>>> steering rotation.
>>>>> But a flexible axle could give more suspension movement to the
>>>>> vehicle (just what you claim for the steertube). But the
>>>>> railway companies never regarded that as desirable - you Nat
>>>>> springing, you fit it in places where it doesn't screw up
>>>>> bearings or make more complicated bearing design necessary.
I see this is another case of "Tar Baby".
>>>> It's not flexing in an RR application. RR wheels turn and don't
>>>> fret.
>>>>>>>>>>> I really can't imagine why you think that a design that is
>>>>>>>>>>> perfectly adequate on a 1/2 ton motorcycle is going to be
>>>>>>>>>>> incapable of supporting a small proportion of that without
>>>>>>>>>>> failing in a fraction of the mileage on a bicycle.
>>>>>>>>>> That's because you don't understand the cause of dimples by
>>>>>>>>>> fretting, something that doesn't occur on most motorcycles.
>>>>>>>>> On the contrary, it used to be commonplace. Right up to
>>>>>>>>> when they started fitting taper roller bearings as standard.
>>>>>>>>> Strange that.
>>>> Well, maybe if your experience is so, you ought to explain to the
>>>> doubters what caused the problem on M/C's.
>>> High pressures on oscillating point contacts breaking down
>>> lubrication film.
>> That is called fretting damage. Where is the disagreement with
>> this assessment.
However, it is not "point contact" but rather oscillating contact
instead of rolling contact. That is why both ball bearings and roller
bearings are subject to this mode of failure.
>>>>>> None of the M/Cs I experienced had fretting damage to the head
>>>>>> bearings, although after the fact it seems possible.
>>>>> Standard conversion kits were available in the '70's and '80's
>>>>> not only through magazines but from many local motorcycle
>>>>> dealers. Once the industry started fitting them as standard
>>>>> equipment, the kits disappeared.
>>>>> I must have fitted several dozen, as not only did I fit them to
>>>>> all my own bikes but all my mates had me help out with theirs,
>>>>> once they all knew that I had done it already.
>> So how did these M/C s need head bearing replacements if it didn't
>> occur.
> Well, clearly it did occur, as I pointed out and you denied. But it
> was certainly widely believed by many people - including some
> serious engineers - that the main difference between taper roller
> and ball bearings in a motorcycle application was the tolerance to
> poor lubrication, owing to the much lower pressures involved in a
> line contact versus a point contact.
That was before they considered reading "Rolling Bearing Analysis".
Just because they were engineers, doesn't protect them from this
folklore about the vibrational failures of bearings.
> I have no reason to disbelieve them, since sufficiently frequent
> regreasing normally prevented the problem in the first place, and
> much longer service intervals gave very good bearing life after
> conversion.
I don't think you have evidence to substantiate that claim.
>> I suspect the conversions ceased because they caused no
>> improvement, just as the bicycle roller bearing units didn't. It
>> was all a big misunderstanding and today we have the compound ball
>> and plain bearing headsets that don't subject the rolling elements
>> of the bearings to off axis skewing.
> The conversions became unnecessary because the manufacturers adopted
> taper rollers as standard.
> Of course, you probably don't believe Honda, Kawasaki, Suzuki,
> Yamaha, Ducati, Triumph, BMW, etc know anything about engineering,
> so they must have got it wrong.
Folklore has a strong attachment and "Rolling Bearing Analysis" is a
far larger tome than the subject would require if it weren't for a
large population of engineering disbelievers. I have understanding
for that with "the Bicycle Wheel" that was widely attacked after
publication, especially by engineers who should have known better.
>>>> So what was the explanation for the occurrence if it was so
>>>> common?
>>> High pressures on oscillating point contacts breaking down
>>> lubrication film.
Nd causing weldments that repeatedly ripped out, being infinitesimally
small, as magnification showed. That is why the dimples have a matte
finish instead of a shiny Brinell finish.
>>>>>>>> Tapered roller bearings are not a solution as the bicycle
>>>>>>>> industry discovered, after a brief attempt at using them.
>>>>>>>> They generated linear radial dimples even faster than ball
>>>>>>>> bearings made oval dimples. Under magnification you'll
>>>>>>>> notice that the dimples are matte finish rather than shiny
>>>>>>>> smooth as Brinell dents are. That is because they aren't
>>>>>>>> dents, but rather fretting erosion of thousands of
>>>>>>>> weld-and-break-outs from the races caused by lubrication
>>>>>>>> failure, the classic mode in fretting damage.
>>>> Tapered roller bearings are not immune to fretting damage as you
>>>> can discover in "Rolling Bearing Analysis". Therefore, I find
>>>> that an expensive and ineffective design change. Tapered rollers
>>>> don't fit in the same space as a ball bearing that it is to
>>>> replace.
>>> So I imagined all the ones that I changed on all the motorcycles?
>>> The ones that had been fitted with ball bearings and I changed to
>>> taper rollers?
Not at all. They just didn't alter the occurrence of fretting damage.
>> If they persisted in their use, they are probably dead today.
> Why, when the motorcycle manufacturers themselves adopted the
> method? Ball bearings were used to start with because they are
> cheap. Taper rollers are more expensive. Manufacturers needed
> convincing that buyers appreciated the difference, and it was the
> extent of the aftermarket modification trade that convinced them.
They are not immune to the folklore that rides as free baggage with
engineers who did not study tribology. The stuff you are writing is
"common knowledge" among engineers who were not depending on solving
the problem by reading appropriate texts.
>>> I can give you examples from current parts catalogues where the
>>> external dimensions of a taper roller and a ball bearing are
>>> identical, so you are clearly bullshitting here.
The Stronglight roller bearings fit well, but did not survive any
better. Stop calling me names to bolster our beliefs.
>>> Just for an example, look up "Stronglight A9".
>> It is exactly the Stronglight headsets that made the syndrome
>> apparent as did the dimples in my upper head bearing in the forward
>> and rearward quadrants... along with Tedric Harris' tome on
>> "Rolling Bearing Analysis".
> Maybe you should consider consulting something published more
> recently than half a century ago. Both bearings and lubrication
> technology have moved on a bit in that time.
Oh! Physics has probably changes in that time. I see that "the
Bicycle Wheel" is also over aged and similarly no longer valid.
>>> And of course, no bearing is immune to fretting damage in the
>>> absence of suitable lubricant.
Fretting damage IS the absence of suitable lubricant, but the cause
for that condition is its design... occurrence of fretting.
>> Not so. There is no suitable lubricant to prevent it if the
>> undesirable bearing motion occurs.
> A steering head bearing on a two wheeler cannot help having an
> "undesirable motion".
That is why it requires a fretting immune bearing design, which
Shimano and Cane Creek, among others have instituted.
> Nearly all the motion is tiny excursions each side of the centre
> point, and there is no oilbath or pressure feed. Any lubricant has a
> very hard time in that environment, because it needs to be drawn in
> behind the rolling element as it moves one way in order to be there
> when that element move back in the opposite direction (and it's only
> by squeezing the soap that the oil is released from it). The higher
> the pressure, the easier it is for the lubricant film to be broken.
> EP additives in the oil help considerably, but they stink to high
> heaven, and I don't know anyone who really wants their steering head
> to smell like tomcat pee. Molybdenum DiSulphide is an alternative,
> which seems to work pretty well.
It's not the intensity of pressure as I pointed out with the example
of RR locomotive wheels not abler to squeeze water from a shiny wet
track. The RR story about the "Train to Omaha" has much wheel-spin in
it and it isn't even raining... only a faint bit of snowfall.
>>>>>>> If you are any kind of engineer you would know that fretting
>>>>>>> damage cannot occur unless the lubrication film is broken
>>>>>>> down. This does not happen under the lower bearing pressures
>>>>>>> of a line contact bearing unless the lubrication is severely
>>>>>>> neglected or you mount the bearings on something so inadequate
>>>>>>> that it flexes to allow all the load to fall on one or two
>>>>>>> rollers.
It happens under low pressure as my upper head bearing demonstrated by
having substantial dimples the same size as the lower, load carrying
head bearing... and the dimples were only in the fore and aft quadrant
of the races. What more do you need?
>>>> I'm glad you noticed that connection. That IS fretting damage and
>>>> is the only way it occurs.
>>> From lubrication breakdown, yes.
>> That is the definition of fretting damage.
> Not really - an unlubricated bearing can operate without fretting if
> the load is light enough. It is direct contact between the elements
> under pressure that causes the micro welding and pits that define
> fretting.
You made that up. If it makes contact, it will cause fretting damage
as I just explained about my well lubricated upper head bearing that
carried no significant load.
>>> As long as a film of lubricant is maintained between the
>>> components, fretting is impossible. The higher the loading at the
>>> load interface, the more difficult it becomes to maintain that
>>> film.
>> I don't think you understand lubrication films and their
>> durability, and how fretting can upset the interaction.
> I'm not the one who is maintaining that lubrication is irrelevant to
> fretting.
I don't see that anyone made such a claim, only that using the right
lubricant will prevent fretting damage. That is th claim as it was
repeatedly presented in this thread.
>>> You pointed out examples of car suspension bearings fretting, and
>>> I'm sure you don't regard that as being due to angular
>>> displacement of the bearing axis, yet you maintain that this is
>>> the ONLY mechanism for the same thing happening on bicycle
>>> steering head bearings.
>> It results from oscillating motions without major rotation.
>> Rotation replenishes failed lubrication films that have been broken
>> by fretting. That is how ball bearings survive when bearing balls
>> are fully rotating or even for a partial continuous rotation.
> Quite. The angular movement necessary to replenish the lubricant
> film is far greater than the majority of steering head movement.
Only on straight roads. At first, few off-road MTB's had dimpled
bearings because they had continuous steering motion on trails.
>>>>>> That IS the definition of fretting damage. The needle head
>>>>>> bearings for bicycles had no shortage of fretting dimples.
>>>>>> That's why they are gone!
>>>>> And nothing at all to do with the fact that taper roller bearings
>>>>> are something you can get easily and cheaply at a bearing factor,
>>>>> instead of having to go to an LBS to by specialist parts at a
>>>>> premium. And of course, the maker may be able to claim a couple
>>>>> of ounces of weight reduction from the flexible steering tube.
I don't believe you can get tapered roller head bearings for bicycle
today. There would be no benefit and because there are head bearings
that do not get fretting damage.
>>>> You cannot get them to fit readily where ball bearings were
>>>> designed.
>>> Except for the ones that are the same dimensions.
>>...and failed to prevent further fretting damage.
> Like the ones I've already described? Which completely cured the
> problem?
I'm sorry, knowing what MR Harris analyzed and what I have seen in
fretting damage and studied in Tribology, I can't take that on your
say so.
>> The classics were with auto wheel and differential bearings, along
>> with gear failure in steering and pinions. You might investigate
>> the various failed patents for steering gears by Ross, Gemmer,
>> Saginaw, and others who tried. All of which failed and were
>> replaced by rack-and-pinion that is far cruder than these elegant
>> designs.
>>> The ones I fitted to motorcycles certainly didn't require
>>> alteration of the bearing seats on either head tube or steerer,
>>> and gave an identical stack height.
>> That doesn't mean they solved the problem, if there was a fretting
>> problem.
> Why, do you think it was brinelling?
I never claimed there was any Brinelling. That was the claim of
others in a previous thread on head bearing failures. It was the
contention of those who disagreed with my reference to "Rolling
Bearing Analysis" and fretting as the cause.
> That would be quite an accomplishment, through several inches of
> tyre and suspension travel. And as already pointed out, it DID
> solve the problem - so well that the manufacturers adopted it.
That was my contention as well.
>>>>>>>>>>> Keeping them adjusted and lubricated right is pretty much
>>>>>>>>>>> essential though.
>>>>>>>>>> So why did bicyclists put up with indexed steering for more
>>>>>>>>>> than a century, most of these bicycles being maintained by
>>>>>>>>>> good mechanics?
>>>>>>>>> Nobody I've ever know "put up with" indexed steering - they
>>>>>>>>> replaced the bearings and learned to keep them adjusted and
>>>>>>>>> lubricated.
>>>> Talk to the bike shop folks who ministered to these riders over
>>>> the years, and consider why the swiveling cartridge bearing was
>>>> introduced by Shimano.
>>> Well, they wouldn't want to admit that they'd over-tightened the
>>> steerer, would they?
>> They didn't! You can't ride an over tightened steerer, especially
>> no-hands something all good bikies do on road and track alike.
>>>>>>>> There was no escape, while replacing bearings was an expensive
>>>>>>>> way of dodging the issue for a short time.
>>>>>>> Millions of riders of traditional upright bicycles would
>>>>>>> disagree with you.
>> Please, Andrew Muzi, speak up. You are being accused in this
>> thread.
>>>>>>>>>>>> For fretting damage. Modern head bearings have their
>>>>>>>>>>>> fretting motions (flexing of the steertube) separated
>>>>>>>>>>>> from rotary steering motions.
>>>>>>>>>>>> Today, head bearings, unlike the one in the URL, have a
>>>>>>>>>>>> plain bearing for fork swivel and a ball bearing for
>>>>>>>>>>>> steering rotation. You'll notice that the Rudelli
>>>>>>>>>>>> design even believes in roller bearings. That was a
>>>>>>>>>>>> major misunderstanding of fretting damage and came and
>>>>>>>>>>>> went long ago. These guys should get some practice with
>>>>>>>>>>>> automotive wheels, drive pinions and their failed
>>>>>>>>>>>> tapered roller bearings, learn about fretting failures.
>>>>>>>>>> You might read about dimpled head bearings before educating
>>>>>>>>>> wreck.bike all about it. You are treading on thin ice, so
>>>>>>>>>> to speak.
>>>>>>>>> That from someone who never realised that they occurred on
>>>>>>>>> motorcycles.
>>>> How did one notice ball bearing dimples on motorcycles that have
>>>> enough engine vibration to completely obscure such motion and
>>>> sound (chattering head bearings when the front end is bounced)?
>>> Notchy low speed cornering and hideous handling at higher speeds, if
>>> you hadn't been checking it properly at normal maintenance
>>> intervals. Basically the whole handling degrades into "pig on
>>> roller-skates" territory.
>> I don't get your analogy. Fretted head bearings did not cause a
>> loss of control in the limits most of us experienced. It was
>> mainly the chattering front-end that warned that it was getting
>> worse.
> Maybe you should check that with a few experienced motorcyclists.
I rode a lot of motorcycle before switching to bicycling and knew
experienced M/C repair shops.
>>> In this country it was easily picked up at the annual mandatory
>>> safety check (MOT test), on which it had it's own entry on the
>>> list of mandatory checks, and an entire section in the testers
>>> manual specifying exactly how the check should be made.
>> I don't recall ever being subjected to a "safety check" and I've
>> been rinding bike for more than 70 years. Who performs thee
>> checks?
> Government approved mechanics, working at approved MOT (ministry of
> transport) test centres.
Well aren't we lucky here in the USA, not to have such government
intrusion. I am unaware of anyone having a safety problem with any
two wheeler due to head bearing wear.
>>> That seems to be an amazingly comprehensive provision for
>>> something that according to you just doesn't happen (or did you
>>> change your mind on that now? it's hard to keep track)
>> Please explain what you mean by this apparently facetious comment.
> You keep saying that it doesn't happen on motorcycles - I've pointed
> out that not only does it happen, but that the problem was regarded as
> serious enough that checking for it was included in annual mandatory
> safety checks of motorcycles.
So what did you mean by your comment?
Oh! How about a design change? For bicycles the problem has been
solved. I take it the occurrence is not widespread enough to warrant
a design change by the motorcycle industry.
>>>>>> Fretting damage to rolling bearings occurs wherever such
>>>>>> bearings are used to hold a static position on a vibrating
>>>>>> machine for any period. Just read "Rolling Bearing Analysis".
>>>>> So nothing to do with the rocking from the steer tube? Just
>>>>> breakdown of lubrication film, which takes high loadings which
>>>>> are much greater in ball bearings, with their almost point
>>>>> contact with the races instead of rollers, with their line
>>>>> contact.
>> That is a static position of the bicycle riding in a straight line
>> while road vibrations oscillate flex in the steertube. Please
>> explain the point you are trying to make.
> The point is that the small movements of the steering head bearing
> necessary to stay upright while just riding along are quite
> sufficient to cause fretting damage even when there is NO measurable
> flexing of the steerer.
Not true. Fretting is in such a small rotation of a ball or needle
bearing that it lies mainly in the elastic contact patch and therefore
allows no lubricant replenishment.
> The example is there on most motorcycles, as is the cure - taper
> rollers and adequate lubrication.
> Ball bearings work for short periods, but the point loading is so
> much higher that lubrication intervals are so short as to be
> unacceptable to most users.
It is not point loading. Just take a look at "Rolling Bearing
Analysis" where these items are shown in enlarged drawings and
microscope pictures. I see you don't understand how ball bearings
support loads.
> Trevor seems to manage with weekly oiling, but most users won't do
> that, and taper rollers extend the interval to months, which is far
> more acceptable to most users.
I doubt it. I believe he is so religiously attached to the belief
that it doesn't occur with proper lubrication that he doesn't follow
through.
>>>> I think you should consider that even railways do not displace
>>>> water from rails with the polished steel wheels on shiny rails
>>>> and must use sand under the wheels to maintain traction. Liquids
>>>> in thin films do not behave as fluidly as most people imagine.
>>>> The same goes for oil in rolling bearings.
>>> I don't seem to be the one suffering from a misunderstanding of
>>> lubricant films here, unless you can explain how fretting can
>>> occur even where the film is maintained.
That is a contradiction. It is fretting motion that breaks down the
lubricant film so the scenario you want is self contradictory.
>> The film cannot be maintained in the presence of fretting. That is
>> where the problem lies.
> Wrong way round. Fretting damage only occurs when the film breaks
> down.
I think you are stuck in a conundrum.
>>>>>>>> Rarely, and no one worries about it today. As I mentioned,
>>>>>>>> cars had the problem with dimpled steering gears. I worked
>>>>>>>> on them as a child in grade school. We had it on Fords and
>>>>>>>> Chevrolets.
>>>>>>> So was that caused by flexible components?
Steel is flexible. That is why it can be used for springs.
>> The driver's control of the steering wheel was flexible as was the
>> steering oscillation of the wheels that have a "roll radius" about
>> which they turn steer, a radius designed to keep the steering
>> linkage under tension. Wheel center lies outside of the king-pin
>> for each front wheel (in spite of having been replaced by ball
>> joints).
>>>>>> It was caused by oscillating contact. Again, read "Rolling
>>>>>> Bearing Analysis" where the subject is explained in detail.
>>>>> So is it oscillating contact from micro-movements of the
>>>>> steering, or is it off-axis rocking, from flexing in the
>>>>> steerer?
>>>> It is involuntary wheel steering from road roughness that causes
>>>> side-to-side motion in the steering gear, damaging bearings and
>>>> tooth flanks of the mechanism.
>>> It would be far easier if you just answered the question as asked
>>> instead of obfusticating it. You seem to be agreeing that it was
>>> the first (very small oscillations of the steering), but seem to
>>> be trying to phrase it differently. Is this so you can claim
>>> later that you never agreed with my analysis?
>> With what part of fretting did is disagree?
> En Anglais, S'il vous plais.
>>>>> What I'm saying is that if you remove the problem of flexing in
>>>>> the steerer, the remaining stresses are easily dealt with by
>>>>> using line contact bearings instead of point contact ones, as
>>>>> they lower the peak load and leave it at a level that most
>>>>> decent quality lubrication can cope with perfectly adequately
>>>>> (although the frequency of re-lubrication will depend on choice
>>>>> of lubricant). EP additives stink, but molybdenum disulphide
>>>>> forms a very strong, very low friction, and highly tenuous layer
>>>>> on the metal components, and is easy and inexpensive to get (but
>>>>> is black, so don't get it on anything you care about the
>>>>> cosmetic appearance of).
>> How do you remove the problem of flexing in the steertube. I see
>> not way around that although making a bearing that is not affected
>> by it has been demonstrated.
> You make it strong enough that it can do it's job properly. Just
> like they have done in the past, and as they still do on
> motorcycles.
>>>> As I mentioned repeatedly, fretting damages roller bearings as
>>>> fast as ball bearings. Bicycle needle bearings demonstrated that
>>>> adequately and automotive wheel and differential tapered roller
>>>> bearings did likewise.
>>> Your understanding is flawed, as I've demonstrated by actual
>>> real-world examples to the contrary.
>> I don't think you have, at least not to the people working on the
>> problem and their solutions. You might talk to the Cane Creek
>> people.
If Shimano is not as easily reachable.
> I don't claim the credit myself - The people who produced the taper
> roller conversions for motorcycles managed to prove it adequately to
> the people at Honda, Kawasaki, etc. and I suspect that those
> companies are not short of engineers capable of evaluating the
> solution.
Shimano and Cane Creek use ball bearings. Roller bearings of any kind
do not prevent fretting damage. That has been tried by Stronglight
and failed.
http://www.canecreek.com/component-headsets
>> where you can see the solution to the problem.
> I can see they've found a way to accommodate inadequate steerer
> rigidity.
A steerer cannot be made stiff enough to prevent fretting.
> I'm not sure that going from a $10 headset to a $125 headset is a
> sensible alternative to just making the steerer strong enough to
> resist off-axis movement.
It isn't a trivial design change, but saves the user money in the long
term.
>>> Of course, one confounding factor is that it's clearly possible to
>>> wreck any bearing by poor installation or inadequate maintenance.
Let's not accuse the bicycle assemblers. It is fretting that causes
dimpled head bearings, not impact.
>> Do you understand why these new head bearings are not affected by
>> steertube flex?
> Do you understand that if the steerer is strong enough, flex isn't a
> problem?
Not true.
How heavy is "strong enough"? Even a solid steertube could flex
enough to cause fretting damage. I hope you are aware that steertubes
have more than twice as thick walls as fork blades and still flex
more.
>>>>>>>>> Of course, I didn't need to read about that - I saw it, felt
>>>>>>>>> it, and learned to fix it for myself.
>>>>>> And you probably didn't need to go to school either, because
>>>>>> you learned all that while maturing.
>>>>> I fully agree that I learned far more of use out of school than
>>>>> in school. Some of those things got taught in school later, but
>>>>> many didn't. And even those subjects that school did catch up
>>>>> on, they left out most of the explanations of WHY things worked
>>>>> that way which my father (a chartered engineer) and mother (head
>>>>> of a large school's maths department) were particularly good at.
>>>>> So much of school was spent helping the other kids understand
>>>>> the things I already did.
>>>> Apparently you didn't, because you failed bearing analysis and
>>>> fretting. I think you suffered from hubris.
>>> You've shown that your "understanding" of the subject does not
>>> align with what actually happens in the real world. This proves
>>> that it is you that has failed.
>>I don't see that you demonstrated what actually happens.
>>>>>>>> You didn't fix it (get rid of it), only spent money on new
>>>>>>>> races once in a while. That's what most riders did.
>>>>>>> Yeah - I can live with once every 150,000 miles. Of course,
>>>>>>> they may not last that long if you don't maintain them.
>>>>>> It was more like 50 miles. Stop faking it.
>>>>> I never once had to make a further replacement of steering head
>>>>> bearings on a motorcycle once I had fitted taper rollers instead
>>>>> of balls, One of the motorcycles managed an additional 150,000
>>>>> miles after that treatment, and the steering head was still
>>>>> fine, although most of the rest of the bike was falling apart by
>>>>> then and it was parted for spares. The frame and forks went
>>>>> together, so I've no idea what the remaining life was after
>>>>> that.
>>>> It was possible to ignore indexed steering. I know of folks who
>>>> didn't recognize from where the chatter in their forks arose.
>>> It may have been possible to ignore it for a while, but in this
>>> country it would be identified at MOT test and the vehicle banned
>>> from road use until repaired and retested.
>> Who performs these tests, that I seem have to missed in all my
>> bicycling days.
> Government approved motorcycle mechanics, working at government
> approved test centres.
> They are mandatory for all motor vehicles here annually, once the
> vehicle reaches three years of age, and they have been for a very
> long time.
>>> I'm not sure why anyone would want to ignore their bike (motor or
>>> pedal) handling like a three legged cow in a sandpit, but the need
>>> to test for it in the MOT shows that there really are people that
>>> stupid or insensitive.
>> As I mentioned, it does not seriously affect handling, and that his
>> how it can progress to an discomforting noise.
> If it didn't affect handling, most people would have lived with
> it,and the government would not have made it a part of the mandatory
> annual safety test.
> The handling of a motorcycle with shot steering head bearings is
> utterly evil, and any motorcyclist old enough to remember the days
> of ball bearing headsets (and who has any mechanical aptitude or
> riding ability) would agree.
>>>>>>> But you don't seem to be able to get your story straight.
>> I think you stand fairly alone in that perception.
> Do you believe that the problem of fretting head bearings creating
> indexed steering can affect motorcycles?
> You keep changing between saying it can't, and claiming that taper
> rollers didn't cure it.
On any application where fretting originally occurred with ball
bearings. It is not the ball but the vibrating contact that causes
fretting damage.
>>>>>>> You say it never happened to motorcycle head bearings at the
>>>>>>> same time as saying that most riders kept replacing bearings
>>>>>>> in order to live with it. You can't have it both ways.
>>>>>> There you go putting words into my writing. Where did I say it
>>>>>> "never" occurred?
>>>>> In your statement:
>>>>>>>>>> That's because you don't understand the cause of dimples by
>>>>>>>>>> fretting, something that doesn't occur on most motorcycles.
>> I think you overlooked the word "most".
> I did, but I can assure you that there was a time when it really did
> affect most motorcycles (all Japanese models certainly, at a time
> when they had over 90% of the UK market).
>>>>>> Fretting damage attacks any rolling element bearing receiving
>>>>>> oscillating loads. That's how steering gears failed in cars of
>>>>>> old from driving on straight roads, just as bicycle head
>>>>>> bearings do. A rack & pinion steering gear will not come to
>>>>>> the rescue of bicycle head bearings as it did for cars,
>>>>>> something the plain swiveling head bearing did.
>>>>> My Jaguar XJ didn't suffer from indexing of the needle rollers
>>>>> in it's suspension linkages either, although the owners club
>>>>> reported it as possible in badly maintained and poorly
>>>>> lubricated examples.
>> I am unfamiliar with the suspension on that car and take your word
>> for it.
>>>> Cars suffered from "homing" in the steering gear, apparent from
>>>> slop in the straight ahead position that, when adjusted, caused
>>>> binding to either side of straight ahead.
>>> I don't think most people would be surprised by the revelation
>>> that things wear most in the places where most use is made of
>>> them. It is only an issue if that wear is faster than should be
>>> expected, when you need to consider the reason, which can be due
>>> to design, installation or maintenance inadequacies.
>> Nothing gets more use than rod and main bearings in cars that get
>> far more rotations than most other bearings in cars. I think your
>> judgment on that "rule" is misplaced.
> If you think my judgment is wrong, maybe you could describe which
> part of a rod or main bearing is subject to more use than other
> parts of the same bearing?
> That those bearings get more use than other bearings, made of
> different materials, with different loads, and with different
> lubrication, is also less than surprising, as well as being less
> than relevant.
I'm tired of messing with "Tar Baby"
Sayonara.
Jobst Brandt
thirty-six
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