Headset cheap fix - works
Clyde
not want to take the time to install a new one.
I read this trick in the Complete Guide to Bicycle
Maintenance and Repair, not my favorite book, but the
only place I have read this trick.
I removed my front wheel, brake cable, and computer
wire, and loosened the stem bolt (threaded stem).
Then I spun the fork around 360 degrees a few times.
Put it all back together, and the indexing is gone.
I guess that the bearings got moved around just enough
to make a difference.
Clyde
Pete Biggs
> I removed my front wheel, brake cable, and computer
> wire, and loosened the stem bolt (threaded stem).
> Then I spun the fork around 360 degrees a few times.
> Put it all back together, and the indexing is gone.
> I guess that the bearings got moved around just enough
> to make a difference.
Sometimes even just regreasing the headset works... for a short while. I
tried all kinds of tricks to cure an old headset - including using loose
balls and rotating the cups. None worked in the long run. Sorry to be
negative but I bet your symptoms will return soon.
~PB
Chris Zacho The Wheelman
loose balls will do the trick even better, as it will be less likely to
"re-index". You will have to add one ball to make up the difference.
There is no need to do this to the top bearing, as it's not under
compression as much as the bottom, therefore it has less af a tendancy
to "index"..
"May you have the wind at your back.
And a really low gear for the hills!"
Chris Zacho ~ "Your Friendly Neighborhood Wheelman"
Chris'Z Corner
http://www.geocities.com/czcorner
Zog The Undeniable
> Taking the caged bearings out of the lower cup and replacing them with
> loose balls will do the trick even better, as it will be less likely to
> "re-index". You will have to add one ball to make up the difference.
>
> There is no need to do this to the top bearing, as it's not under
> compression as much as the bottom, therefore it has less af a tendancy
> to "index"..
IME the top race indexes much worse. Axial compression doesn't have all
that much to do with headset wear - it's the back-to-front flexing of
the fork that wears them out.
ant
> Taking the caged bearings out of the lower cup and replacing them with
> loose balls will do the trick even better, as it will be less likely to
> "re-index". You will have to add one ball to make up the difference
this is good advice.
re: a previous poster's warning that this trick doesnt work for long:
IMHE, this works fine, in terms of takign away the old indexing.
however, the headset will never be smooth. was this was the responder
was referring to? the dents havent dissapeared, they just dont all
line up with the balls at the same time.
if your priority is smooth newlike headset, solution is new headset.
if $ is a problem, a tange passage for 7 bucks or so feels like every
other headset to my undiscerning hands.
if your priority is no indexing, becuase your steerer snaps dead ahead
when you dont want it to, the loose ball trick will generally fit the
bill.
anthony
Pete Biggs
>> Taking the caged bearings out of the lower cup and replacing them
>> with
>> loose balls will do the trick even better, as it will be less likely
>> to "re-index". You will have to add one ball to make up the
>> difference
>
> this is good advice.
> re: a previous poster's warning that this trick doesnt work for long:
>
> IMHE, this works fine, in terms of takign away the old indexing.
> however, the headset will never be smooth. was this was the responder
> was referring to?
No, I don't know why, but indexing shortly returned after I replaced caged
with loose balls (top & bottom, as many as possible) - and the headset was
greased and adjusted carefully after the modification. So I do not
believe it is a good enough cure for all cases (nor rotating the cups or
polishing them).
> the dents havent dissapeared, they just dont all
> line up with the balls at the same time.
Perhaps there can be so many dents that enough balls line up (?). I
should stress that this was "light indexing" that I experienced - just
enough to detect when turning bars gently with wheel off the ground -
probably not enough to make any difference on the road at normal speed but
disturbing all the same as I didn't want it to get any worse.
BTW, I now use Stronglight A9 headsets with roller bearings - which work
to my satisfaction. I know according to some that roller bearings can
index in theory but I don't believe it will ever happen with the models
I'm using*, and even if it did, the tracks that the rollers run on can be
replaced easily (these cups don't wear).
* 1. Absolutely no sign of notching in my experience so far
2. I've never heard of a real case of it
~PB
Carl Fogel
Dear Pete and others,
I'm baffled. If indexing results from fretted
dimples worn into the bearing surface, how will
removing and replacing ball bearings fix anything?
Won't the same steel balls drop into the same
pits, whether loose or caged?
What am I missing?
Carl Fogel
jobst....@stanfordalumni.org
>>> Taking the caged bearings out of the lower cup and replacing them
>>> with loose balls will do the trick even better, as it will be less
>>> likely to "re-index". You will have to add one ball to make up the
>>> difference
>> This is good advice. Re: a previous poster's warning that this
>> trick doesn't work for long:
>> IMHE, this works fine, in terms of taking away the old indexing.
>> However, the headset will never be smooth. Was this was the
>> responder was referring to?
> No, I don't know why, but indexing shortly returned after I replaced
> caged with loose balls (top & bottom, as many as possible) - and the
> headset was greased and adjusted carefully after the modification.
> So I do not believe it is a good enough cure for all cases (nor
> rotating the cups or polishing them).
Consider that mainly the fore and aft quadrant of the bearing need to
chatter, so it is possible, adding two balls to 20, leaves most of the
dimples aligned or nearly aligned with their original dimples, so it
should be no wonder that the symptom returns rapidly, it requiring
only slight wear to get back into the groove.
>> The dents haven't disappeared, they just don't all line up with the
>> balls at the same time.
> Perhaps there can be so many dents that enough balls line up (?). I
> should stress that this was "light indexing" that I experienced -
> just enough to detect when turning bars gently with wheel off the
> ground - probably not enough to make any difference on the road at
> normal speed but disturbing all the same as I didn't want it to get
> any worse.
You might review the FAQ item:
http://draco.acs.uci.edu/rbfaq/FAQ/8f.13.html
> BTW, I now use Stronglight A9 headsets with roller bearings - which
> work to my satisfaction. I know according to some that roller
> bearings can index in theory but I don't believe it will ever happen
> with the models I'm using*, and even if it did, the tracks that the
> rollers run on can be replaced easily (these cups don't wear).
> 1. Absolutely no sign of notching in my experience so far
> 2. I've never heard of a real case of it
There are other good reasons to not use roller bearings. That's why
they have not been used by the main manufacturers Campagnolo and
Shimano and have not been chosen by the specialists King and Cane Cr.
"Crane Geek" is not a great name for dyslexics to say.
Jobst Brandt
jobst....@stanfordalumni.org
jobst....@stanfordalumni.org
> I'm baffled. If indexing results from fretted dimples worn into the
> bearing surface, how will removing and replacing ball bearings fix
> anything?
A typical Campagnolo head bearings has 20 balls held in a cage for the
purpose installing them without tedious manual insertion of balls into
a greased cup (outer race). This spacing is greater than close-packed
and will allow two additional balls to be placed in the same space if
the cage is removed.
> Won't the same steel balls drop into the same pits, whether loose or
> caged?
By about 20/22's some of them miss the mark. As I said, this isn't a
good fix and soon returns to where it was. The problem is that the
head bearing chatters and if adjusted to not chatter, it binds when
not steering straight ahead.
> What am I missing?
Yes?
http://draco.acs.uci.edu/rbfaq/FAQ/8f.13.html
Jobst Brandt
jobst....@stanfordalumni.org
ant
> Consider that mainly the fore and aft quadrant of the bearing need to
> chatter, so it is possible, adding two balls to 20, leaves most of the
> dimples aligned or nearly aligned with their original dimples, so it
> should be no wonder that the symptom returns rapidly, it requiring
> only slight wear to get back into the groove.
interesting.
a cool problem solvers's product might be a new bearing retainer to
'fix' indexed headsets. an LBS with a customer who doesnt want to pay
labor and new headset cash would only need remove the old bearings,
and put the new retainer with balls in.
to avoid the problem jobst points out, the retainer could either have
far fewer balls in it, like 15 instead of 20 (not ideal) or instead
could have an irregular spacing of bearings, where you could still fit
18 or so in, i would haphazardly guess.
would be pretty cheap to make. a two part production process. stamp
steel plate. bend retainer fingers in. maybe it could be worth it?
idly,
anthony
JP
On the other hand, enough people have been buying Stronglight roller
bearing headsets for what, about two decades, that they have not felt
market pressure to change. I recently bought an A9 myself, not because
I think there is anything wrong with ball bearing headsets, or
anything necessarily superior about roller bearings, but because I
wanted a French headset for my French bike, and there is no practical
evidence that I shouldn't go with a Stronglight. Replaceable bearings
and bearing tracks do seem to make the risk pretty low, though. Would
you say that there is an economic incentive to both bike shops and
manufacturers to use a design that requires replacing the whole
headset instead of just the bearing set when the cups are damaged? And
they can say to you while they're installing the new one, "See what
happens when you don't take care of your headset?"
JP
jim beam
> they have not been used by the main manufacturers Campagnolo and
> Shimano and have not been chosen by the specialists King and Cane Cr.
the primary reason from what i know is economics, not mechanics.
rollers cost significantly more than balls and require a different race
machining setup. balls already last very well - there's no reason to
bother "upgrading".
jb
Carl Fogel
Dear Jobst,
Ignorance is bliss, since it makes things so
interesting. I know that a caged-ball-bearing
assembly is much easier to install, but I
thought that its real virtue was that the
hard steel balls rotated against the soft
cage metal instead of wearing against each
other.
That is, a dozen ball-bearings kept from
touching each other by a soft metal cage
are generally better than a baker's dozen
of the same ball-bearings uncaged and stuffed
into the same space, all rubbing against
each other, even though the extra ball
might seem like a good idea.
Is this just another of my misconceptions?
Carl Fogel
dianne_1234
<pbiggmellon{remove_fruit}s2...@onetel.net.uk> wrote:
>BTW, I now use Stronglight A9 headsets with roller bearings - which work
>to my satisfaction.
As they did for me for many years. Light, cheap, what's not to like?!
> I know according to some that roller bearings can
>index in theory but I don't believe it will ever happen with the models
>I'm using*,
One of the A9s finally indexed on our tandem. Photo here:
http://www.geocities.com/dianne_1234/bikes/index.html
> and even if it did, the tracks that the rollers run on can be
>replaced easily (these cups don't wear).
>
>* 1. Absolutely no sign of notching in my experience so far
> 2. I've never heard of a real case of it
See above.
jim beam
> http://www.geocities.com/dianne_1234/bikes/index.html
that's an interesting pic!
maybe i'm just seeing what i want to see, but it appears that you have
classic brinelling going on there.
i.e.
_
/ \
\_/ < crater "lip"
______/\ /\______
\_/
there appears to be material deformed _up_ out of the crater forming a
lip as well as that indented down. text book brinell! not what the
"lubrication failure" folks will want to see.
dianne_1234
I wish I'd saved the parts. They've long since gone in the trash...
:-(
A Muzi
>>>>Taking the caged bearings out of the lower cup and replacing them
>>>>with
>>>>loose balls will do the trick even better, as it will be less likely
>>>>to "re-index".
> "Pete Biggs" <pbiggmellon{remove_fruit}s2...@onetel.net.uk> wrote in message news:<bq6jlg$1u7u69$1...@ID-144931.news.uni-berlin.de>...
>>with loose balls (top & bottom, as many as possible) - and the headset was
>>greased and adjusted carefully after the modification.
Carl Fogel wrote:
> I'm baffled. If indexing results from fretted
> dimples worn into the bearing surface, how will
> removing and replacing ball bearings fix anything?
> Won't the same steel balls drop into the same
> pits, whether loose or caged?
> What am I missing?
You're not.
Index headsets index less severely when the cups are removed
and reinstalled - the balls center on a dimple on one side
but fall between divots on the other race. In theory,
tossing retainers and using loose balls (changing the ball
count) can possibly prevent the bearings from aligning in
more than a few dimples. Simply spinning the headset can
only give momentary relief - the balls will find their homes
again quickly.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
A Muzi
> a cool problem solvers's product might be a new bearing retainer to
> 'fix' indexed headsets.
-snip-
Been done , sort of.
An outfit named TefSeal (Tulsa? Ok City?) used to make a
seal for normal 1039 headsets and a nylon torus to replace
the 2100 retainer. You could get another few (sticky)
seasons on an indexed headset with a pair of those for five
bucks.
But headsets are so darned cheap. They cost,what, $20~50
for ten or fifteen years? Why "fix" 'em?
LBS phenomenon I've noticed - a guy who will think nothing
of $150+ for new rubber, cables and tape every season
bitches on and on about an index headset every 10+ years.
Go figure
kh6...@pe.net
: But headsets are so darned cheap. They cost,what, $20~50
: for ten or fifteen years? Why "fix" 'em?
: LBS phenomenon I've noticed - a guy who will think nothing
: of $150+ for new rubber, cables and tape every season
: bitches on and on about an index headset every 10+ years.
: Go figure
: --
: Andrew Muzi
: www.yellowjersey.org
: Open every day since 1 April, 1971
Andrew,
My bikes seem to have indexed headsets. I can feel the indexing when the
bike is in the stand. But I cannot feel it when I am riding.
Is this one of those things that you can just ignore?
--------------------------------
Bob Masse' kh6...@PE.NET
--------------------------------
A Muzi
>
> : But headsets are so darned cheap. They cost,what, $20~50
> : for ten or fifteen years? Why "fix" 'em?
>
> : LBS phenomenon I've noticed - a guy who will think nothing
> : of $150+ for new rubber, cables and tape every season
> : bitches on and on about an index headset every 10+ years.
> : Go figure
kh6...@pe.net wrote:
> My bikes seem to have indexed headsets. I can feel the indexing when the
> bike is in the stand. But I cannot feel it when I am riding.
> Is this one of those things that you can just ignore?
Sure. Ignoring it or changing it won't make your bike any
faster. If it isn't annoying, it is not a problem IMHO.
But next time you are in the mood to deal with this, why not
run a set of gauges across that frame/fork? Might show a
problem. Be sure to check the column with a straightedge, too.
Or buy a headset with installation from a trusted shop with
the express expectation that you want at least, say, six
years from it. Review the history with the mechanic and
maybe he can point up the problem / suggest a solution. This
is s solvable problem, not really expensive.
jobst....@stanfordalumni.org
>>> I'm baffled. If indexing results from fretted dimples worn into the
>>> bearing surface, how will removing and replacing ball bearings fix
>>> anything?
A typical Campagnolo head bearings has 20 balls held in a cage for the
purpose installing them without tedious manual insertion of balls into
a greased cup (outer race). This spacing is greater than close-packed
and will allow two additional balls to be placed in the same space if
the cage is removed.
>>> Won't the same steel balls drop into the same pits, whether loose or
>>> caged?
By about 20/22's some of them miss the mark. As I said, this isn't a
good fix and soon returns to where it was. The problem is that the
head bearing chatters and if adjusted to not chatter, it binds when
not steering straight ahead.
>>> What am I missing?
Yes?
http://draco.acs.uci.edu/rbfaq/FAQ/8f.13.html
> Ignorance is bliss, since it makes things so interesting. I know
> that a caged-ball-bearing assembly is much easier to install, but I
> thought that its real virtue was that the hard steel balls rotated
> against the soft cage metal instead of wearing against each other.
What do you believe occurs between a steel cage and bearing balls that
is dependent on heat treatment and hardness? There is no load on the
cage other than during insertion, and rotational speeds are at less
than one revolution per second at most. I think you present an odd
perception of ball bearings. At high speeds and a moving bearing,
such as a roller connecting rod bearing, has large cage-to-ball/roller
loads but that isn't bicycling. Such cages are carefully made of
brass to support such loads.
> That is, a dozen ball-bearings kept from touching each other by a
> soft metal cage are generally better than a baker's dozen of the
> same ball-bearings uncaged and stuffed into the same space, all
> rubbing against each other, even though the extra ball might seem
> like a good idea.
Oooh, bearing balls rubbing against each other. What are you
imagining occurs on such contact when bearing balls slide on hard
steel races under enormous loads such as in a BB. Consider that balls
cannot roll without sliding in a curved race that partially matches
the ball radius.
> Is this just another of my misconceptions?
Definitely!
Jobst Brandt
jobst....@stanfordalumni.org
jobst....@stanfordalumni.org
>> There are other good reasons to not use roller bearings. That's
>> why they have not been used by the main manufacturers Campagnolo
>> and Shimano and have not been chosen by the specialists King and
>> Cane Cr.
> The primary reason from what I know is economics, not mechanics.
> Rollers cost significantly more than balls and require a different race
> machining setup. Balls already last very well - there's no reason to
> bother "upgrading".
You mean downgrading. Rollers have a binding problem because they
don't center themselves on their conical races, shifting off axis to
causing varying amounts of drag that is apparent on a closely adjusted
bearing. With a little slack, the rollers just slide around,
unnoticed by the person making adjustments. The usual perception is
that the bearing was too tight and had to be run looser. In fact it
wasn't too tight but without slop, it binds from the roller complement
running off axis. These things are dogs. I have some with fretting
dimples from the days when I believed what the bike shop said.
Jobst Brandt
jobst....@stanfordalumni.org
Carl Fogel
Dear Jim,
I agree that Dianne's picture looks that way,
but I'm not sure whether I'm seeing another
miserable optical illusion like the funny-spoke
picture in another recent thread.
There are three rings in her picture.
The left ring is the roller ring.
The middle ring is the one where you and I think
we see material deformed up and out of the crater.
(I don't know whether fretting forms lips, too).
There do seem to be dark bands on either side of
a trough in some of the indexing damage in this
picture, and these bands do look sort of like
thrown-up lips from impact craters.
But look at the third ring, the one on the right,
and the trough just to the left of the shiny area,
at about 10 o'clock. It doesn't seem to show the
lips that we think that we see elsewhere--I can't
see any dark bands on either side.
So maybe the light on some of the indexing marks
is hitting not thrown-up lips (a phrase that I'm
proud to have written twice), but rather discolored
bands on smooth metal that look like lips with the
light right, but are really just bluing? That damage
in the shiny area seems quite different, no raised
lips at all.
Now if Dianne will just go through her trash for
the last few years, I'm sure that this can be
cleared up easily . . .
Carl Fogel
Carl Fogel
Dear Jim,
I just looked at those wretched rings again
and now wonder whether what might have been
raised lips or bluing bands is actually only
the internal dark reflection on troughs that
are wider than we think.
I hate optical illusions.
Carl Fogel
jobst....@stanfordalumni.org
>> BTW, I now use Stronglight A9 headsets with roller bearings - which
>> work to my satisfaction.
> As they did for me for many years. Light, cheap, what's not to
> like?!
>> I know according to some that roller bearings can index in theory
>> but I don't believe it will ever happen with the models I'm using*,
> One of the A9s finally indexed on our tandem. Photo here:
http://www.geocities.com/dianne_1234/bikes/index.html
>> and even if it did, the tracks that the rollers run on can be
>> replaced easily (these cups don't wear).
>> * 1. Absolutely no sign of notching in my experience so far
>> 2. I've never heard of a real case of it
> See above.
Well lo and behold, the picture completely captures the problem with
roller head bearings. As is visible, the roller complement was
running off axis to the limit, running off the edge of the race to one
side. The rollers fretted deep dimples in the edge of the races where
they were running to the high side of the cone. The dark debris next
to the dimples is not a ridge but discoloration. That is more
apparent from the ones that have light reflections on them where no
upset material upset material rises above the original contour.
Since this is fretting damage, not Brinelling, no upset material could
be present. I have similar ones that I generated in a short time over
many miles. This convinced me about 30 years ago that these were just
another ill conceived gimmick that did not address the problem. They
don't help!
Jobst Brandt
jobst....@stanfordalumni.org
jim beam
> we see material deformed up and out of the crater.
> (I don't know whether fretting forms lips, too).
> There do seem to be dark bands on either side of
> a trough in some of the indexing damage in this
> picture, and these bands do look sort of like
> thrown-up lips from impact craters.
somehow carl, i just /knew/ it would be you that showed up with this
question...
since you like stories, here's one for you. when i was a kid, i got a
nice shiny new racing bike. i took it out for a ride, and while trying
to be clever, i ran into the back of a car. my fault entirely. and
from that moment on, that headset was indexed. it was a high end tange
head set iirc.
anyhow, when years later i learned about hardness testing & the nature
of brinell indentations, i remembered back to that accident and
everything dropped into place - indexing is brinell indentation. i
asked one of my profs about it and he confirmed that this is also common
in ball bearings that do not roll significantly, like a car being
transported on a railroad truck for instance.
the problem that seems to cause the most conceptual difficulty here is
that it also happens over time and that bearings are "too hard" to
deform. truth is, ball/roller bearings /do/ deform very slightly.
that's why failed wheel bearings appear to be pitted - the surface
minutely deforms repeatedly over time, many millions of cycles, and
small chunks of the surface fatigue & spall away - both from balls & races.
that's also why ball bearings are not usually considered suitable for
very high load applications and for shock loads. iirc, [timken?] tried
to introduce roller bearings into rail road axle applications, and while
they were theoretically capable of decent life with their projected
loads, these folks had not adequately allowed for the shock loading that
occurs each time a solid steel wheel goes over a join in two pieces of
rail. they were a miserable failure. you'll never see roller bearings
on railroad axles today - they're all journal bearings, just like the
journals on the shock-loaded crankshaft of your car. [and no, journals
are not suitable for bike headsets because they have "stiction" as well
as float.]
getting back to bike headsets, #1 on a google search shows this:
http://www.gordonengland.co.uk/hardness/brinell.htm
it clearly shows the deformation pattern from a brinell indentation,
including the crater "lip". in practice, this lip may not be massively
noticable because it's going to be largely flattened each time the ball
rolls over it, but over time, the crater become more pronounced, and of
course, the index will become noticable.
jb
jobst....@stanfordalumni.org
>> One of the A9s finally indexed on our tandem. Photo here:
http://www.geocities.com/dianne_1234/bikes/index.html
> That's an interesting pic!
> Maybe I'm just seeing what I want to see, but it appears that you
> have classic Brinelling going on there.
> i.e.
> _
> / \
> \_/ < crater "lip"
> ______/\ /\______
> \_/
> There appears to be material deformed _up_ out of the crater forming
> a lip as well as that indented down. Text book Brinell! Not what
> the "lubrication failure" folks will want to see.
Come right out and say what you mean. Your snide allusions will get
you nowhere as you see what you want to see. What you seeing is
classic steering fretting failure, nothing less. I have such head
bearings in my collection of failed parts and they look the same.
There is no upset material. If there were it should have formed in
the first miles of descending on cobbles... but it didn't, although
I'm sure thats one place fretting damage progresses rapidly if it is a
straight road.
Jobst Brandt
jobst....@stanfordalumni.org
ant
>
> An outfit named TefSeal (Tulsa? Ok City?) used to make a
> seal for normal 1039 headsets and a nylon torus to replace
> the 2100 retainer. You could get another few (sticky)
> seasons on an indexed headset with a pair of those for five
> bucks.
>
> But headsets are so darned cheap. They cost,what, $20~50
> for ten or fifteen years? Why "fix" 'em?
>
> LBS phenomenon I've noticed - a guy who will think nothing
> of $150+ for new rubber, cables and tape every season
> bitches on and on about an index headset every 10+ years.
> Go figure
i know, i know. and if it were my bike..
but so many folks come in with indexed headsets and dont really want
to buy a 20 dollar headset and 10 bucks labor. old folks who use the
bike to get groceries, and teenagers with beater 10 speeds and
whatnot. i just thought it'd be pretty nifty if there were a quick
fix. maybe LBSs could hand these out and charge a few bucks for labor
the same way that we used to replace the broken spring assemblies on
old cantilevers. no charge for the part. few bucks for the labor.
happy customer who didnt want new cantis.
'cool to hear they existed, though.
anthony
jobst....@stanfordalumni.org
>> The middle ring is the one where you and I think we see material
>> deformed up and out of the crater. (I don't know whether fretting
>> forms lips, too). There do seem to be dark bands on either side of
>> a trough in some of the indexing damage in this picture, and these
>> bands do look sort of like thrown-up lips from impact craters.
> Somehow Carl, I just /knew/ it would be you that showed up with this
> question...
> Since you like stories, here's one for you. When I was a kid, I got
> a nice shiny new racing bike. I took it out for a ride, and while
> trying to be clever, I ran into the back of a car. My fault
> entirely. From that moment on, that headset was indexed. It was a
> high end Tange head set IIRC.
Stop misattributing cause and effect. A bent steertube will cause a
bicycle to have a preferred steering position, especially with an
older head bearing that doesn't embody spherical alignment. Don't
pass on idle conjecture as proof of a disproven concept before
analyzing the nature of your bearing problem. Head bearings cannot
Brinell. If you believe so, please take a cast-off head bearing that
is not dimpled and pound on it with a hammer and show us the shiny
Brinell indentations. You won't find any.
> Anyhow, when years later I learned about hardness testing & the nature
> of Brinell indentations, I remembered back to that accident and
> everything dropped into place - indexing is Brinell indentation. I
> asked one of my profs about it and he confirmed that this is also common
> in ball bearings that do not roll significantly, like a car being
> transported on a railroad truck for instance.
Oh how odd. And how did he explain that cars shipped by train could
suffer Brinelling? I think you got a dud for a materials professor.
What manner of college was this?
> The problem that seems to cause the most conceptual difficulty here
> is that it also happens over time and that bearings are "too hard"
> to deform. Truth is, ball/roller bearings /do/ deform very
> slightly. That's why failed wheel bearings appear to be pitted -
> the surface minutely deforms repeatedly over time, many millions of
> cycles, and small chunks of the surface fatigue & spall away - both
> from balls & races.
I strongly suggest you read Rolling Bearing Analysis by Tedric Harris
before passing on myth and lore as science. Wheel bearing failure is
known s spalling and has nothing to do with Brinell indentation.
http://dogbert.abebooks.com/servlet/BookSearchPL
enter Tedric Harris as author and you'll find inexpensive sources.
At Amazon you can get the book new for $190 but that's fluff.
> That's also why ball bearings are not usually considered suitable
> for very high load applications and for shock loads. IIRC,
> [Timken?] tried to introduce roller bearings into railroad axle
> applications, and while they were theoretically capable of decent
> life with their projected loads, these folks had not adequately
> allowed for the shock loading that occurs each time a solid steel
> wheel goes over a join in two pieces of rail. They were a miserable
> failure. You'll never see roller bearings on railroad axles today -
> they're all journal bearings, just like the journals on the
> shock-loaded crankshaft of your car. [And no, journals are not
> suitable for bike headsets because they have "stiction" as well as
> float.]
Stop the blather. Today no non-roller bearing rail car is allowed on
US class one railroads. They all have Timken, Hyatt, or SKF roller
bearings. Where do you pick up these urban legends? Just the same
it's good you came out of the closet and exposed your attachment to
myth and lore so that readers are forewarned.
> Getting back to bike headsets, #1 on a Google search shows this:
http://www.gordonengland.co.uk/hardness/brinell.htm
That's all fine but where are you going to get a 3000kg force on a
head bearing single ball? Besides, well hardened races usually crack
before plastically deforming, somewhat like a high speed steel drill
that you cannot bend in its fluted length. I have a Shimano Dura Ace
BB cup that had such a failure.
> It clearly shows the deformation pattern from a Brinell indentation,
> including the crater "lip". In practice, this lip may not be
> massively noticeable because it's going to be largely flattened each
> time the ball rolls over it, but over time, the crater become more
> pronounced, and of course, the index will become noticeable.
Because there are such tests and materials does not make it happen in
ball or roller bearing races. Please read up on bearing failure
before trying to educate wreck.bike.tech on the matter.
Jobst Brandt
jobst....@stanfordalumni.org
jim beam
>>including the crater "lip". In practice, this lip may not be
>>massively noticeable because it's going to be largely flattened each
>>time the ball rolls over it, but over time, the crater become more
>>pronounced, and of course, the index will become noticeable.
>
> Because there are such tests and materials does not make it happen in
> ball or roller bearing races. Please read up on bearing failure
> before trying to educate wreck.bike.tech on the matter.
1. you need to read your testing lit.
2. check
http://www.timken.com/products/bearings/services/valueadd/prevent.asp.
3. learn to leave your abused childhood at the door.
then we can talk.
ant
> Stop misattributing cause and effect. A bent steertube will cause a
> bicycle to have a preferred steering position, especially with an
> older head bearing that doesn't embody spherical alignment. Don't
> pass on idle conjecture as proof of a disproven concept before
> analyzing the nature of your bearing problem. Head bearings cannot
> Brinell. If you believe so, please take a cast-off head bearing that
> is not dimpled and pound on it with a hammer and show us the shiny
> Brinell indentations. You won't find any.
so a head-on crash couldnt cause headset indexing?
a bike came in once that had just been crashed. on its lower HS
bearings, the race was *severely* dimpled (as much or more than ive
ever seen before), but just on the front side.
i dont have a lot of experience to think back about, but i never had
seen such a pattern before. the other heavily indexed examples must
have been either less dimpled up front, or more equally dimpled around
the circumference.
curious about what it was i was seeing,
anthony
jobst....@stanfordalumni.org
>> Stop misattributing cause and effect. A bent steertube will cause
>> a bicycle to have a preferred steering position, especially with an
>> older head bearing that doesn't embody spherical alignment. Don't
>> pass on idle conjecture as proof of a disproven concept before
>> analyzing the nature of your bearing problem. Head bearings cannot
>> Brinell. If you believe so, please take a cast-off head bearing
>> that is not dimpled and pound on it with a hammer and show us the
>> shiny Brinell indentations. You won't find any.
> So a head-on crash couldn't cause headset indexing?
No but it could bend the steertube of the fork and cause binding and
one sided loading of the lower ball bearing. That in turn could
accelerate fretting damage if the bicycle were used coasting down long
straight hills, the cause of indexed steering.
> A bike came in once that had just been crashed. On its lower HS
> bearings, the race was *severely* dimpled (as much or more than I've
> ever seen before), but just on the front side.
So how did it look before the crash. There are many indexed head
bearings running around, most of which are recognized only when they
come to a mechanic who recognizes the problem. As I said, try
dimpling a head bearing by hammering on it. A bicycle has a tire
between its bearings and the ground.
> I don't have a lot of experience to think back about, but I never had
> seen such a pattern before. The other heavily indexed examples must
> have been either less dimpled up front, or more equally dimpled
> around the circumference.
The effect is strongest in the front and read quadrant of the lower and
upper bearing. I have examples that have these dimples on the upper
bearing as well as the lower.
> Curious about what it was i was seeing.
You are seeing fretting damage:
jobst....@stanfordalumni.org
> My bikes seem to have indexed headsets. I can feel the indexing
> when the bike is in the stand. But I cannot feel it when I am
> riding. Is this one of those things that you can just ignore?
The problem arises when the chattering of the loose bearing annoys the
rider as the fork clunks while riding straight ahead. This is evident
when the bicycle is lifted by the handlebar stem and allowed to bounce
on the front wheel. A loud disconcerting chatter is heard indicating
there is excessive bearing clearance. However this goes away when the
wheel is turned slightly to either side and the test repeated.
If this bearing is adjusted to not chatter when straight ahead, it
will bind to either side, making no hands riding difficult. That is
the bearing cannot be adjusted, it must be replaced... preferably with
one of the better ones that have a separation of rotary and swiveling
motion.
Yes it can be ignored just as a hole in the muffler in a car can.
Clyde
that separate rotary and swiveling motion?
Clyde
<jobst....@stanfordalumni.org> wrote in message
news:dKKyb.126$XF6....@typhoon.sonic.net...
Carl Fogel
Dear Jim,
That's a drawing that you suggest looking at,
not a picture like the one that Dianne put up
and that you and I are wondering about. The
drawing explains the Brinell test procedure,
a deliberate deformation with special tools.
Do you see raised lips in Dianne's picture
in the shiny area at 10 o'clock in the ring
on the right? I can't think of any lighting
trick that would make them disappear, so I'm
wondering whether what look like lips elsewhere
are just discolorations as Jobst has now suggested
in this thread or just internal reflections on
the concave surface.
A month or two ago, I illustrated my tendency
to be taken in by optical illusions. I'm looking
at the same disgusting Presta valve right now.
It's threaded all the way down to where the base
disappeared into the rubber and is clearly silver
colored. The knurled nut on the end of the valve
is clearly brassy in color. The base that was
embedded in the inner tube rubber is also clearly
brassy in color.
Some posts suggested that the silvery color was
nickel plating, so I hacksawed a chunk out of the
stupid valve to see whether it was silvery all the
way through or brassy underneath.
less than half ______________________
sawed out | |______ brassy nut
:---------------- silvery smooth |_____
| interior ______|
| ________________________________|
|_____| silvery outer
brassy flared base
Damned if I can tell what color the thin wall of
the cross section is. My crude hacksawing left
the walls sloping inward a bit, much like the
damage-troughs in Dianne's picture. Hold the
miserable valve one way and the walls appear
silvery. Hold it another way and they seem to
change color and become brassy.
I suspect that the walls really are brass-colored
with a thin inner and outer silver coating. But
the surface of the cut is so shiny and the two colors
so close that with the light right, the truly brassy
surface is reflecting the smooth silvery interior and
frustrating hell out of me.
Neither direct sunlight nor a magnifying glass resolve
the matter. Sawing completely through would probably
settle things, but I'm keeping the wretched valve intact
as a reminder of how ridiculously difficult such simple
things can be.
Carl Fogel
jobst....@stanfordalumni.org
> My bikes seem to have indexed headsets. I can feel the indexing
> when the bike is in the stand. But I cannot feel it when I am
> riding. Is this one of those things that you can just ignore?
The problem arises when the chattering of the loose bearing annoys the
rider as the fork clunks while riding straight ahead. This is evident
when the bicycle is lifted by the handlebar stem and allowed to bounce
on the front wheel. A loud disconcerting chatter is heard indicating
there is excessive bearing clearance. However this goes away when the
wheel is turned slightly to either side and the test repeated.
If this bearing is adjusted to not chatter when straight ahead, it
will bind to either side, making no hands riding difficult. That is
the bearing cannot be adjusted, it must be replaced... preferably with
one of the better ones that have a separation of rotary and swiveling
motion.
Yes it can be ignored just as a hole in the muffler in a car can.
jobst....@stanfordalumni.org
>> If this bearing is adjusted to not chatter when straight ahead, it
>> will bind to either side, making no hands riding difficult. That
>> is the bearing cannot be adjusted, it must be replaced...
>> preferably with one of the better ones that have a separation of
>> rotary and swiveling motion.
> Which better models of bearing are you referring to that separate
> rotary and swiveling motion?
jim beam
really?
how come timken say:
"Brinelling is the *plastic* deformation of bearing element surfaces due
to extreme or repeated shock loads."
my emphasis.
you've heard of timken i presume. are they just another "bike type"
sales driven company selling to unsophisticated retail consumers? why
does this happen to fit the experience of indexing after crashing a
brand new headset?
you're really pushing your luck on this one jobst.
Pete Biggs
> Rollers have a binding problem because they
> don't center themselves on their conical races, shifting off axis to
> causing varying amounts of drag that is apparent on a closely adjusted
> bearing. With a little slack, the rollers just slide around,
> unnoticed by the person making adjustments. The usual perception is
> that the bearing was too tight and had to be run looser. In fact it
> wasn't too tight but without slop, it binds from the roller complement
> running off axis. These things are dogs. I have some with fretting
> dimples from the days when I believed what the bike shop said.
The Stronglight A9 headset on my bike is working no slop and no binding.
How do you explain that?
I have had binding problems with a Stronglight O'Light on another bike.
This model has smaller rollers in "sealed cartridges".
~PB
Pete Biggs
> One of the A9s finally indexed on our tandem. Photo here:
> http://www.geocities.com/dianne_1234/bikes/index.html
How many miles before the failure?
(Unfortuantely the web page is not loading for me so I can't see the pic).
~PB
jobst....@stanfordalumni.org
>> Rollers have a binding problem because they don't center themselves
>> on their conical races, shifting off axis to causing varying
>> amounts of drag that is apparent on a closely adjusted bearing.
>> With a little slack, the rollers just slide around, unnoticed by
>> the person making adjustments. The usual perception is that the
>> bearing was too tight and had to be run looser. In fact it wasn't
>> too tight but without slop, it binds from the roller complement
>> running off axis. These things are dogs. I have some with
>> fretting dimples from the days when I believed what the bike shop
>> said.
> The Stronglight A9 headset on my bike is working no slop and no
> binding. How do you explain that?
How do YOU explain it? How many miles does it have and what sort of
bicycle are you riding and where? This all makes a difference.
> I have had binding problems with a Stronglight O'Light on another
> bike. This model has smaller rollers in "sealed cartridges".
I have not seen this unit but what do you mean by sealed cartridges?
Rollers have been discredited and are not a solution to anything that
ball bearings don't do better. How do you explain that the leading
head bearing manufacturers other than Stronglight do not use rollers?
I assume you saw the pictures of the dimpled roller head bearing
offered here in this topic. How do you explain that?
Jobst Brandt
jobst....@stanfordalumni.org
A Muzi
-snip what are presta valve bodies made of? Couldn't tell
from a hacksawed section-
Maybe try a file instead. The resistance of brass to a file
is distinctive and the color is obvious:
http://www.yellowjersey.org/nuvalve.html
Gary Young
When I go to that web page, I see the following:
"False brinelling is recognisable by the grooves worn into the
raceways by axial movement of the rollers during transportation."
Jobst has said many times that the fretting mechanism he describes is
also known as false brinelling. In any event, it's not true or
"classic" brinelling as you maintain, is it?
I think I see a pattern -- the more adament and obnoxious "Jim Beam"
or "Tux Lover" or whatever his name is, the more spectacularly wrong
he is.
Do you care to give your real name and your qualifications? That way,
maybe we could get a sense of when you've reached the end of your
tether.
Pete Biggs
>> The Stronglight A9 headset on my bike is working no slop and no
>> binding. How do you explain that?
>
> How do YOU explain it?
But I am not claiming that they cannot work, I don't need to explain it.
Your posts imply that they can't work without either slop or binding.
That is not true.
> How many miles does it have and what sort of
> bicycle are you riding and where? This all makes a difference.
This latest case: Only fitted recently, to Raleigh tourer, done less than
1500 miles, general riding on roads in the UK. It is working well - with
no slop, no binding, smooth steering.
I previously used one a road bike for about 10,000 miles (without
replacing bearings, regreased three or four times). I did have to leave a
trace of play in (from the start) but I thought that was because the head
tube was not faced properly. It was not enough play to notice *except*
when rocking the bike hard with front brake on, and steering felt good, no
trace of indexing, binding or excessive friction.
I don't see the big deal if the innards need replacing every so often if
headset is used for more miles or in tougher conditions - when the parts
are so inexpensive, readily available and easy to fit.
>> I have had binding problems with a Stronglight O'Light on another
>> bike. This model has smaller rollers in "sealed cartridges".
>
> I have not seen this unit but what do you mean by sealed cartridges?
Stronglight describe them as "needle cartridge bearings". Unlike the A9
with loose parts, bearing retainer fits tight into the tracks and
incorporates plastic seals. Designed to be maintenance-free, the parts
require firm prising to separate (I did this to remove seals to improve
performance). THIS model was a dog right from the start.
> Rollers have been discredited and are not a solution to anything that
> ball bearings don't do better.
After experiencing slight indexing problems with ordinary headsets, I
bought an A9 after reading many reports of good performance (from users
and experts) and because I liked the idea that the head cups would never
need replacing.
> How do you explain that the leading
> head bearing manufacturers other than Stronglight do not use rollers?
I wasn't actually claiming rollers are superior to balls but merely
challenging the idea that they can't ever work well at all. We have to
wonder how the A9 has been so popular for so long.
FSA is a popular make. They have models with rollers. I could probably
find some others as well.
> I assume you saw the pictures of the dimpled roller head bearing
> offered here in this topic. How do you explain that?
It would be interesting to find out how much good service that headset
provided before it failed. I don't see why it matters if it was tens of
thousands of miles as A9 bearings are cheap to replace. Replacement every
so often should prevent the problem.
I can't see the pictures - website doesn't load.
~PB
Donald Gillies
>Jim Beam writes:
>>> One of the A9s finally indexed on our tandem. Photo here:
> http://www.geocities.com/dianne_1234/bikes/index.html
>> That's an interesting pic!
>> Maybe I'm just seeing what I want to see, but it appears that you
>> have classic Brinelling going on there.
>> i.e.
>> _
>> / \
>> \_/ < crater "lip"
>> ______/\ /\______
>> \_/
I have a very old headset from someone else's bike that i'm interested
in trying to restore (rather than discard). What do you think about
this proposal for fixing the identations in the races (i won't use
"pitting" or "brinelling" or "fretting", to avoid stirring up the
mechE's on this list) :
1. For each bearing race, take one side of the headset (cup or race)
and rotate by 1/2 the space between bearings. Goal is to reduce
the pit depth halfway.
2. For all 4 races/cups, rotate by 1/4 the space between bearings.
Goal is to have the "straight ahead" direction not correspond to
any particular pit orientation.
3. Remove the bearing retainer, add bearings until they don't all
seat, then remove 3 bearings, yielding a headset that's 2 bearings
short of a full load. Hearsay from Barnett's bicycle manual.
4. Reinstall everything and pack headset until fork turns freely with
no front wheel / handlebar, but doesn't "click" when front brake
is locked and i'm on the seat and bike is rocked.
5. Ride 1000 + mi on the headset to reduce or redistribute the
bearing indentations.
6. Sand/refinish the races and then rechrome the headset to make it
look like new. Will nickel plating of the chrome layer be too
soft for the heaset races ?? Should I mask off the races before
attempting to rechrome this headset ?? Or should I just skip the
nickel plating in the races ?? Thanx,
- Don Gillies
San Diego, CA
Jose Rizal
He's claimed to be a "materials guy". This obviously qualifies him as
an expert in absolutely everything, and a pox on you and everyone else
who have the gall to ask him for quantitative proof of his
super-fantastic theories.
Tim McNamara
Seems to me if you're going to take gratuitous potshots at people, you
should have the balls to clearly identify who they are with proper
attribution.
Tim McNamara
>> You are seeing fretting damage:
>
> really?
>
> how come timken say:
>
> "Brinelling is the *plastic* deformation of bearing element surfaces
> due to extreme or repeated shock loads."
In which case there'd be no relationship between Brinelling and
mileage, because sufficiently hard impacts could come within 100 yards
of leaving the bike shop on the first ride. Yet that's not what's
being described here.
And if your claim that impact causes Brinelling in headsets was true,
then such damage would not occur in track headsets which see shock
loading from riding over bumps nor in pro team spare bikes that have
never been ridden but only clamped in fork-mounting roof racks.
And again, have the guts to do correct attributions.
jobst....@stanfordalumni.org
>>> The Stronglight A9 headset on my bike is working no slop and no
>>> binding. How do you explain that?
>> How do YOU explain it?
> But I am not claiming that they cannot work, I don't need to explain
> it. Your posts imply that they can't work without either slop or
> binding. That is not true.
I am fairly sure you don't know that. How about giving it the front
end bounce test to see that it doesn't have slop and then give it the
vertical swing test to see that it isn't binding. Lift the bicycle
onto your shoulder and lean it forward just enough to make the wheel
point straight ahead and then lightly let it swing from side to side.
It is this test that all clearance free roller head sets showed that
they were running off axis as the one pictured at:
http://www.geocities.com/dianne_1234/bikes/index.html
You'll notice that the rollers can even cross up in their plastic cage
let alone the whole cage slipping off to one side as this one did.
>> How many miles does it have and what sort of bicycle are you riding
>> and where? This all makes a difference.
> This latest case: Only fitted recently, to Raleigh tourer, done less
> than 1500 miles, general riding on roads in the UK. It is working
> well - with no slop, no binding, smooth steering.
I think it's too early to say anything about the head set after such a
short run. Study the picture on the web carefully and see if you can
endorse such a design. In my appreciation it is flawed in several
aspects that I have explained in detail.
> I previously used one a road bike for about 10,000 miles (without
> replacing bearings, re-greased three or four times). I did have to
> leave a trace of play in (from the start) but I thought that was
> because the head tube was not faced properly. It was not enough
> play to notice *except* when rocking the bike hard with front brake
> on, and steering felt good, no trace of indexing, binding or
> excessive friction.
The bounce test is the only one that replicates reality because it is
this chatter that one hears while lightly braking on average pavement,
the place where the bearing is in the load transition zone. It is
this rattle that is most disconcerting and brings people to try and
adjust clearance only to discover that without clearance, the bearing
binds.
> I don't see the big deal if the innards need replacing every so
> often if headset is used for more miles or in tougher conditions -
> when the parts are so inexpensive, readily available and easy to
> fit.
The innards are the plastic cage and the races. What's left?
>>> I have had binding problems with a Stronglight O'Light on another
>>> bike. This model has smaller rollers in "sealed cartridges".
>> I have not seen this unit but what do you mean by sealed cartridges?
> Stronglight describe them as "needle cartridge bearings". Unlike
> the A9 with loose parts, bearing retainer fits tight into the tracks
> and incorporates plastic seals. Designed to be maintenance-free,
> the parts require firm prising to separate (I did this to remove
> seals to improve performance). THIS model was a dog right from the
> start.
The A9 shown on the web site and the one on my shelf have their
cylindrical rollers in a plastic cage. I have never seen a
"cartridge" bearing roller head set.
>> Rollers have been discredited and are not a solution to anything
>> that ball bearings don't do better.
> After experiencing slight indexing problems with ordinary headsets,
> I bought an A9 after reading many reports of good performance (from
> users and experts) and because I liked the idea that the head cups
> would never need replacing.
Well we see what the experts know and don't know. I'm not so sure
that "experts" are actually being quoted here, like Jim Beam Whiskey's
professor who taught him all about Brinelling. Its a sham.
>> How do you explain that the leading head bearing manufacturers
>> other than Stronglight do not use rollers?
> I wasn't actually claiming rollers are superior to balls but merely
> challenging the idea that they can't ever work well at all. We have to
> wonder how the A9 has been so popular for so long.
For short distances, their feet of clay probably won't show up but if
used to the tune of 5-10K miles a year they are dogs.
> FSA is a popular make. They have models with rollers. I could
> probably find some others as well.
FSA has some of the goofiest designs on the market. I would not hold
them up as a standard for bicycle equipment. At InterBike, I saw all
sorts of things some equipment freaks will buy just to be avant-garde.
Let's get back to people who, even if its trial and error, come up
with working solutions... because they try their stuff.
>> I assume you saw the pictures of the dimpled roller head bearing
>> offered here in this topic. How do you explain that?
> It would be interesting to find out how much good service that headset
> provided before it failed. I don't see why it matters if it was tens of
> thousands of miles as A9 bearings are cheap to replace. Replacement every
> so often should prevent the problem.
> I can't see the pictures - website doesn't load.
Go to a place where you can see it. It is an excellent picture of
exactly what is wrong with roller bearings in this use.
Jobst Brandt
jobst....@stanfordalumni.org
ant
> > So a head-on crash couldn't cause headset indexing?
jobst....@stanfordalumni.org wrote in message news
>
> No but it could bend the steertube of the fork and cause binding and
> one sided loading of the lower ball bearing. That in turn could
> accelerate fretting damage if the bicycle were used coasting down long
> straight hills, the cause of indexed steering.
> So how did it look before the crash. There are many indexed head
> bearings running around, most of which are recognized only when they
> come to a mechanic who recognizes the problem. As I said, try
> dimpling a head bearing by hammering on it. A bicycle has a tire
> between its bearings and the ground.
You are right that I did not see this bike before the crash. However,
I felt safe assuming it was crash damage because the bike was so new.
perhaps not brand new, but certainly little used. it was one of these
trek hybrids that gets used once a year for the annual trip to cape
cod.
how long would it take for severe indexing to take place if a bent
steerer was the true cause?
IIRC, the indexing on the top bearing was less severe, ie: much
smaller dimples, or perhaps none at all (can't remember, but i did
note the difference). At the time I thoguht this uneven dimpling also
suggested crash damage, but i cant nail down the science behind this
dubious intuition.
ever curious,
anthony
jobst....@stanfordalumni.org
>>>> One of the A9s finally indexed on our tandem. Photo here:
>> http://www.geocities.com/dianne_1234/bikes/index.html
>>> That's an interesting pic!
>>> Maybe I'm just seeing what I want to see, but it appears that you
>>> have classic Brinelling going on there.
>>> i.e.
>>> _
>>> / \
>>> \_/ < crater "lip"
>>> ______/\ /\______
>>> \_/
> I have a very old headset from someone else's bike that I'm
> interested in trying to restore (rather than discard). What do you
> think about this proposal for fixing the indentations in the races (I
> won't use "pitting" or "Brinelling" or "fretting", to avoid stirring
> up the mechE's on this list) :
> 1. For each bearing race, take one side of the headset (cup or
> race) and rotate by 1/2 the space between bearings. Goal is to
> reduce the pit depth halfway.
> 2. For all 4 races/cups, rotate by 1/4 the space between bearings.
> Goal is to have the "straight ahead" direction not correspond to
> any particular pit orientation.
The dimples don't have any particular bias toward any location and for
typical old style fixed headsets with 20 bearing balls the dimples are
only 18 degrees apart just like the rollers in the picture offered at:
http://www.geocities.com/dianne_1234/bikes/index.html
> 3. Remove the bearing retainer, add bearings until they don't all
> seat, then remove 3 bearings, yielding a headset that's 2
> bearings short of a full load. Hearsay from Barnett's bicycle
> manual.
That is correct. That puts them at 16.363636... degrees apart. From
this you can see that most of the balls will be teetering in or on the
edge of a dimple. Get a new head set and while you're at it get one
of the Shimano, Cane Creek or King units that get around most of this
problem.
> 4. Reinstall everything and pack headset until fork turns freely
> with no front wheel / handlebar, but doesn't "click" when front
> brake is locked and I'm on the seat and bike is rocked.
> 5. Ride 1000 + mi on the headset to reduce or redistribute the
> bearing indentations.
You can try this on a disassembled and cleaned bearing by placing the
balls in the race and rotating it under hand load on the table. I
think you'll see a wave of dimple engagement wandering around the
bearing as it turns. This is doomed to failure. What have you got
against installing a new head set? If it is antique consistency, just
ignore the dimples. They are only functional for someone who descends
hard and rides rough roads where the clunks can be heard.
> 6. Sand/re-finish the races and then re-chrome the headset to make
> it look like new. Will nickel plating of the chrome layer be
> too soft for the headset races? Should I mask off the races
> before attempting to re-chrome this headset? Or should I just
> skip the nickel plating in the races?
It will flake off under load. It is sub surface shear loads that
cause bearing races to spall. These will spall immediately.
Jobst Brandt
jobst....@stanfordalumni.org
jobst....@stanfordalumni.org
>>>> It clearly shows the deformation pattern from a Brinell
>>>> indentation, including the crater "lip". In practice, this lip may
>>>> not be massively noticeable because it's going to be largely
>>>> flattened each time the ball rolls over it, but over time, the
>>>> crater become more pronounced, and of course, the index will become
>>>> noticeable.
>>> Because there are such tests and materials does not make it happen
>>> in ball or roller bearing races. Please read up on bearing
>>> failure before trying to educate wreck.bike.tech on the matter.
> 1. you need to read your testing lit.
> 2. check
http://www.timken.com/products/bearings/services/valueadd/prevent.asp.
> 3. Learn to leave your abused childhood at the door. Then we can
> talk.
The page you list shows a spalled bearing whose race surface broke out
from heavy loading that caused surface fatigue failure. The false
Brinelling picture could just as well be the one here on the
newsgroup:
http://www.geocities.com/dianne_1234/bikes/index.html
Just the same, false Brinelling is not caused by the mechanism cited.
This must be an ancient text that no one has bothered to update.
False Brinelling is caused by fretting, not lateral sliding of
rollers. In fact the roller sliding concept ignores that ball
bearings suffer the same fate if allowed to fret.
You should read Tedric Harris, who is the true authority on Rolling
Element Bearings.
Jobst Brandt
jobst....@stanfordalumni.org
dianne_1234
I'd estimate about 400 to 800 miles, but that's just a guess.
jim beam
> jim beam <u...@ftc.gov> writes:
>
>
>>>You are seeing fretting damage:
>>
>>really?
>>
>>how come timken say:
>>
>>"Brinelling is the *plastic* deformation of bearing element surfaces
>>due to extreme or repeated shock loads."
>
>
> In which case there'd be no relationship between Brinelling and
> mileage, because sufficiently hard impacts could come within 100 yards
> of leaving the bike shop on the first ride. Yet that's not what's
> being described here.
how so? damage accumulates over time. that's like saying "but my brake
pads suddenly wore out". they're worn out, but it either happens over
time or you do something unusual like a long muddy downhill. so what?
i don't get what's hard to understand about this.
> And if your claim that impact causes Brinelling in headsets was true,
> then such damage would not occur in track headsets which see shock
> loading from riding over bumps nor in pro team spare bikes that have
> never been ridden but only clamped in fork-mounting roof racks.
you're getting at false brinelling, right? the condition for that is
that the races are loose and unloaded leading to sliding, not rolling.
unless the team mech hasn't tightened the forks properly, that's not
what you get for a bunch of bikes bouncing around on the roof of a car.
how many times have you taken the groceries home and found a can
dented, an egg cracked or a bottle broken? you can't say these bikes
are not being loaded!
> And again, have the guts to do correct attributions.
attribute what? forgive me being a retard but i don't understand what
you want with this.
i don't understand why this is suddenly a schoolyard pissing match.
jobst gets all bent over what he thought was a snide remark. sorry he
took it that way - there was no personal intent. but then the abuse
starts. i don't get it: why is his dysfunctionality my problem? and if
you or jobst or anyone else feel i'm mistaken, go ahead & point out what
the issue is. i'm always a willing learner if there's some expertise or
experience to be shared. the only thing /i/ want is that it's done
technically, not by childish poo-flinging.
regarding brinelling, there's no rocket science here. any trained
mechanic knows for instance, [or from experience!] that when using a
bearing press, they need to use the proper interfaces to load the
appropriate races only and not cause damage. think about it: a sphere
has practically /zero/ contact area on a flat surface. virtually any
applied force will cause nearly infinite load as the contact area tends
to zero. so there /will/ be deformation, no matter /how/ hard the
material is. a bunch of balls in a snugly curved race attempt to
mitigate the problem, but the truth is, you still get a minute amount of
deformation. [electron microscopes are wonderful things.] now repeat a
bunch of times. see where this is going? if you do it all in the same
spot, you get one indentation, if you do it rolling, you get a
constantly moving deformation zone which leads to fatigue and spalling.
simple, yes?
noone's forcing you or anyone else to read this stuff. if it doesn't
interest you, fine. if you don't agree, fine. this is not religion,
politics or health. we're here because we like bikes, right? hopefully
that means we have something in common.
jb
jobst....@stanfordalumni.org
>>> So a head-on crash couldn't cause headset indexing?
>> No but it could bend the steertube of the fork and cause binding
>> and one sided loading of the lower ball bearing. That in turn
>> could accelerate fretting damage if the bicycle were used coasting
>> down long straight hills, the cause of indexed steering.
>> So how did it look before the crash. There are many indexed head
>> bearings running around, most of which are recognized only when
>> they come to a mechanic who recognizes the problem. As I said, try
>> dimpling a head bearing by hammering on it. A bicycle has a tire
>> between its bearings and the ground.
> You are right that I did not see this bike before the crash.
> However, I felt safe assuming it was crash damage because the bike
> was so new. Perhaps not brand new, but certainly little used. It
> was one of these trek hybrids that gets used once a year for the
> annual trip to cape cod.
> How long would it take for severe indexing to take place if a bent
> steerer was the true cause?
It probably would have little effect other than concentrating the
fretting damage to the rear quadrant of the races because that is the
only place the ball would bear after damaging the steertube. Usually
only the fork blades bend on such collisions but the steertube also
takes a slight bend.
> IIRC, the indexing on the top bearing was less severe, ie: much
> smaller dimples, or perhaps none at all (can't remember, but i did
> note the difference). At the time I thought this uneven dimpling
> also suggested crash damage, but i cant nail down the science behind
> this dubious intuition.
After such a collision, inspecting the frame and fork is important.
Often the kink in the system is only detected by the bicycle not
riding straight ahead no-hands. I often see people riding such bent
frames and when I ask them whether they can ride straight ahead
no-hands, they look at me with disbelief that I would suggest doing
something so stupid and dangerous as riding no-hands. The response is
generally "I never ride no-hands!" with a tone of disgust.
Jobst Brandt
jobst....@stanfordalumni.org
jim beam
> in trying to restore (rather than discard).
that is a highly questionable exercise. it's technically feasible, but
unless you are prepared to spend many times the value of the piece /and/
have access to some interesting machinery and/or the piece is
fundamentally irreplacable, it's just not worth it.
> 1. For each bearing race, take one side of the headset (cup or race)
> and rotate by 1/2 the space between bearings. Goal is to reduce
> the pit depth halfway.
works for the straight-ahead position, but still doesn't get rid of the
previous damage.
> 2. For all 4 races/cups, rotate by 1/4 the space between bearings.
> Goal is to have the "straight ahead" direction not correspond to
> any particular pit orientation.
see above
> 3. Remove the bearing retainer, add bearings until they don't all
> seat, then remove 3 bearings, yielding a headset that's 2 bearings
> short of a full load. Hearsay from Barnett's bicycle manual.
works, but is not "perfect". see above.
> 4. Reinstall everything and pack headset until fork turns freely with
> no front wheel / handlebar, but doesn't "click" when front brake
> is locked and i'm on the seat and bike is rocked.
>
> 5. Ride 1000 + mi on the headset to reduce or redistribute the
> bearing indentations.
???
> 6. Sand/refinish the races and then rechrome the headset to make it
> look like new.
it's not perfect, but istr seeing something on andy muzi's site about
his refinishing bearing races for customers with hard to replace
components. imo, that is your "least bad" technical solution. other
than being content with keeping it "as-is" and viewing it as an
interesting museum piece.
> Will nickel plating of the chrome layer be too
> soft for the heaset races ?? Should I mask off the races before
> attempting to rechrome this headset ?? Or should I just skip the
> nickel plating in the races ?? Thanx,
you're plating on a small section concave surface. this is
a. prone to uneven plate distribution - various field effects
b. prone to rapid spalling.
for a high value/irreplacable component in a shop environment, it's also
possible to spray new material onto the bearing surface and then
regrind, but to be hinest, i've only ever seen this done on large pieces
and i doubt the original races are big enough to survive such a proceedure.
if you really must reuse this headset, your cheapest bet is to just use
the barnett's solution and restrict milage as much as possible.
Pete Biggs
> Pete Biggs writes:
>
>>>> The Stronglight A9 headset on my bike is working no slop and no
>>>> binding. How do you explain that?
>
>>> How do YOU explain it?
>
>> But I am not claiming that they cannot work, I don't need to explain
>> it. Your posts imply that they can't work without either slop or
>> binding. That is not true.
>
> I am fairly sure you don't know that. How about giving it the front
> end bounce test to see that it doesn't have slop and then give it the
> vertical swing test to see that it isn't binding. Lift the bicycle
> onto your shoulder and lean it forward just enough to make the wheel
> point straight ahead and then lightly let it swing from side to side.
It passes the tests. No "noise" detectable when bounced (I know what a
headset with play sounds like when bounced: I recently re-adjusted just to
remind myself after reading these threads!), wheel swings freely.
> It is this test that all clearance free roller head sets showed that
> they were running off axis as the one pictured at:
>
> http://www.geocities.com/dianne_1234/bikes/index.html
I don't think the A9 is "clearance free" though if that means tolerable of
minimal play. I find it can cope with a small amount of clearance - just
enough to enable it to turn lightly but not enough to be at all noticeable
while riding (even over bumps or light or normal braking).
> You'll notice that the rollers can even cross up in their plastic cage
> let alone the whole cage slipping off to one side as this one did.
Do you not think there could have been an unusual cause or exceptional
mileage? Why isn't it more commonly reported with this common headset?
>>> How many miles does it have and what sort of bicycle are you riding
>>> and where? This all makes a difference.
>
>> This latest case: Only fitted recently, to Raleigh tourer, done less
>> than 1500 miles, general riding on roads in the UK. It is working
>> well - with no slop, no binding, smooth steering.
>
> I think it's too early to say anything about the head set after such a
> short run.
My previous run (on other bike with the slight amount of headset play:
which caused absolutely no problems in practice) was 10,000 miles, with no
deterioration in performance.
>> I previously used one a road bike for about 10,000 miles (without
>> replacing bearings, re-greased three or four times). I did have to
>> leave a trace of play in (from the start) but I thought that was
>> because the head tube was not faced properly. It was not enough
>> play to notice *except* when rocking the bike hard with front brake
>> on, and steering felt good, no trace of indexing, binding or
>> excessive friction.
>
> The bounce test is the only one that replicates reality because it is
> this chatter that one hears while lightly braking on average pavement,
> the place where the bearing is in the load transition zone. It is
> this rattle that is most disconcerting and brings people to try and
> adjust clearance only to discover that without clearance, the bearing
> binds.
I am familiar with the rattle that loose headsets cause but the play was
not that much. I find the rocking test, if done vigourously enough,
detects play or clearance that is too small to even notice when bouncing.
I could only feel a small bit of play when rocking hard with brake on
hard, and occasionally at the end of extreme heavy braking as I came to a
stop. No problems at all while riding and the bearings and races
survived. That'll do me - and all from an inexpesnive lightweight headset
that hasn't shown the slightest hint of indexing.
>> I don't see the big deal if the innards need replacing every so
>> often if headset is used for more miles or in tougher conditions -
>> when the parts are so inexpensive, readily available and easy to
>> fit.
>
> The innards are the plastic cage and the races. What's left?
That's all I meant. Races are included in the replacement bearings
package.
>>>> I have had binding problems with a Stronglight O'Light on another
>>>> bike. This model has smaller rollers in "sealed cartridges".
>
>>> I have not seen this unit but what do you mean by sealed cartridges?
>
>> Stronglight describe them as "needle cartridge bearings". Unlike
>> the A9 with loose parts, bearing retainer fits tight into the tracks
>> and incorporates plastic seals. Designed to be maintenance-free,
>> the parts require firm prising to separate (I did this to remove
>> seals to improve performance). THIS model was a dog right from the
>> start.
>
> The A9 shown on the web site and the one on my shelf have their
> cylindrical rollers in a plastic cage. I have never seen a
> "cartridge" bearing roller head set.
The O'Light cartridge also has cylindrical rollers in a plastic cage but
the rollers are much smaller and more numerous; cage snaps tightly into
the races. Several other Stronglight models have same/similar
cartridges. Adjustment and performance was dramatically improved after
removing the seals - and further improved after I replaced the lower half
of the headset with an A9 one (threadless forks on this bike). So I can't
help thinking the free movement of the A9 cage/races helps not hinders.
>>> Rollers have been discredited and are not a solution to anything
>>> that ball bearings don't do better.
>
>> After experiencing slight indexing problems with ordinary headsets,
>> I bought an A9 after reading many reports of good performance (from
>> users and experts) and because I liked the idea that the head cups
>> would never need replacing.
>
> Well we see what the experts know and don't know. I'm not so sure
> that "experts" are actually being quoted here, like Jim Beam Whiskey's
> professor who taught him all about Brinelling. Its a sham.
I'm thinking more about respected British cycling journalists and also
Sheldon Brown whom I seem to remember has written some positive words
about Stronglight headsets.
>>> How do you explain that the leading head bearing manufacturers
>>> other than Stronglight do not use rollers?
>
>> I wasn't actually claiming rollers are superior to balls but merely
>> challenging the idea that they can't ever work well at all. We have
>> to wonder how the A9 has been so popular for so long.
>
> For short distances, their feet of clay probably won't show up but if
> used to the tune of 5-10K miles a year they are dogs.
Ok, thanks, that's a more useful statement than saying they can't work at
all. Personally, I don't mind if I do have replace the bearings & races
every so often and I think they're no problem to manage for plenty more
than 5K a year.
However, I probably will have another go with ball bearings some time out
of ongoing curisosity, perhaps on another bike: either Chorus or a Cane
Creek/Shimano, but any trouble and I'll be back to the A9 pronto.
--------
I would be grateful if any reader could email me the picture at the
following website as I'm having technical trouble seeing it (please email
me first to see if I've already got it). Thanks.
www.geocities.com/dianne_1234/bikes/index.html
email: pbigg...@onetel.net.uk
~PB
Pete Biggs
>> How many miles before the failure?
> I'd estimate about 400 to 800 miles, but that's just a guess.
Oh, I thought you had previously been happy with them and said this then
"eventually" happened? ...Or have you left off some zeros!? (I'm
wondering about total use before failure rather than inability to ride
after problem began).
I'm sorry I still haven't seen the picture, but surely something odd must
have happened if this was after just ~600 miles? Was the adjustment
particularly tight or loose? Anything else unusual at all (besides being
on a tandem).
Thanks.
~PB
Pete Biggs
> I don't think the A9 is "clearance free" though if that means
> tolerable of minimal play. I find it can cope with a small amount of
> clearance - just enough to enable it to turn lightly but not enough
> to be at all noticeable while riding (even over bumps or light or
> normal braking).
Just to make this clearer (because I've been referring to experiences with
three different bikes) :-
1. I've needed no play with my latest A9 (threaded) on my tourer.
2. I had to leave a small amount of play in with A9 (threaded) on
previous road bike from the start - but it worked well and did not
deteriorate.
3. O'Light threadless on new road bike was crap. Ok with seal removed
and bottom replaced with A9, with a tiny bit of play but again no problems
in practice apart from strange binding under strong braking (which I've
not experienced on any bike before and I'm not sure is headset related or
not; might be flex in the aluminium steerer?). I plan to eventually get
head tube faced and try another headset.
~PB
Tim McNamara
> Tim McNamara wrote:
>
>> And again, have the guts to do correct attributions.
>
> attribute what? forgive me being a retard but i don't understand
> what you want with this.
Atribute the text you're replying to the author. Your newsreader
should do this automatically (e.g., the attribution line above, which
is "jim beam <u...@ftc.gov> writes:"). You've made several attacking
posts which do not include the attributions- oddly enough, all of them
being text from posts by Jobst. Your last post, from which I took the
above text, had a correct attribution to me. If you're going to
attack someone, at least be honest and up front about who it is.
Carl Fogel
[snip]
> > > http://www.timken.com/products/bearings/services/valueadd/prevent.asp.
[snip]
Dear Jim, Gary, and Jose,
When I peeked at the timken bearing page,
it pandered to my desire for lurid pictures
of failed bearing surfaces, but it didn't
pander quite far enough.
The pictures of the "false brinelling"
aren't as good as Dianne's pictures
(thanks again Dianne).
That is, there's no enlargement of the "false
brinelling" damage on the Timken page.
But there is an enlargement of the true
brinelling damage on that Timken page--and
I don't understand it.
I thought that true Brinelling would be a dent,
possibly with raised lips, an impact crater.
But the enlargement seems to show nothing but
a shadow or discoloration, with striations
clearly passing through it, as if undamaged.
It's as if the so-called "plastic deformation"
is just burning, not deformation.
Can any of you (or any other kindly soul)
explain what I'm missing in that picture?
I hope this isn't another damned optical
illusion.
More perplexed than usual,
Carl Fogel
A Muzi
>> I have a very old headset from someone else's bike that i'm interested
>> in trying to restore (rather than discard).
>> 6. Sand/refinish the races and then rechrome the headset to make it
>> look like new.
> it's not perfect, but istr seeing something on andy muzi's site about
> his refinishing bearing races for customers with hard to replace
> components. imo, that is your "least bad" technical solution. other
> than being content with keeping it "as-is" and viewing it as an
> interesting museum piece.
only where both time and money have no importance! A lenthy
setup and tedious work.
(jb)> for a high value/irreplacable component in a shop
environment, it's also
> possible to spray new material onto the bearing surface and then
> regrind, but to be hinest, i've only ever seen this done on large pieces
> and i doubt the original races are big enough to survive such a proceedure.
Yes for big engine crankshafts that's a common and
reasonable $200 repair to a $1000 part. Headsets are cheap!
dianne_1234
<pbiggmellon{remove_fruit}s2...@onetel.net.uk> wrote:
>dianne_1234 wrote:
>
>>> How many miles before the failure?
>
>> I'd estimate about 400 to 800 miles, but that's just a guess.
>
>Oh, I thought you had previously been happy with them
Yes, on other bikes. Sorry, I guess didn't make that clear before. :-)
> and said this then
>"eventually" happened?
Yes, eventually in time (the tandem doesn't get used as often as my
single bikes).
> ...Or have you left off some zeros!?
I'm trying to be honest about the mileage, but without an odometer I
could be off by several hundred or so.
> (I'm
>wondering about total use before failure rather than inability to ride
>after problem began).
To my thinking, these are equivalent phrases for the same condition.
Inability to ride (with comfortable control) *is* failure.
>I'm sorry I still haven't seen the picture,
Me, too. I was quite shocked to see the condition myself.
> but surely something odd must
>have happened if this was after just ~600 miles? Was the adjustment
>particularly tight or loose?
I knew of (and used) the drop test, rocking-with-the-brakes-on test,
swinging the fork test, etc. when I installed the headset.
Subsequently I tried very fine adjustments several times as symptoms
began.
> Anything else unusual at all (besides being
>on a tandem).
The steerer tube is 1", small for a tandem these days. It might flex
more as a result, but it's heavily reinforced through the length where
the lower race mounts. (The frame builder added a several inches
length of thick-wall tube into the steerer there.)
The frame's head tube and fork's bearing seat were professionally
reamed, faced and milled using Campy cutters before the headset was
installed.
Nothing else I can think of, except that this was the first failure in
an A9 of many I'd used on single bikes.
>Thanks.
You're welcome!
>~PB
>
Pete Biggs
>> (I'm
>> wondering about total use before failure rather than inability to
>> ride after problem began).
>
> To my thinking, these are equivalent phrases for the same condition.
> Inability to ride (with comfortable control) *is* failure.
I meant number of miles done in total versus number of miles after symtoms
first showed up. I take it you estimate it was less than 800 miles in
total.
> I knew of (and used) the drop test, rocking-with-the-brakes-on test,
> swinging the fork test, etc. when I installed the headset.
Do you think it could have been initially tighter than the A9's used on
your other bikes? Setting just past the point of play is easy enough but
it's not so easy to judge freeness by the swinging test. Some other
factors can influence how easily the forks/wheel swings: eg. cables,
weight, exact test method, etc.
> Subsequently I tried very fine adjustments several times as symptoms
> began.
It may have been too late by then.
~PB
jim beam
would have thought use of a threaded news reader made it obsolete.
Gary Young
Carl,
I'm afraid I'm not competent to answer your question. I'm a legal
reporter with no expertise in these matters (beyond what I've gleaned
from this group). That makes it all the more remarkable, I think, that
I can see through the pathetic exploits of "Jim Beam." He wouldn't be
so intolerable if only he'd leave off snipping at the heels of people
like Jobst who have made genuine contributions to this group.
Carl Fogel
Dear Tim,
When I peek through my Internet Exploder
and Google Gropes to compare your "original
format" with Jim, I notice that he uses
Linux-Mozilla-Gecko, while you use Gnus
and Emacs.
Possibly these differences in your software
explain some of the differences in how
attributions are being done? It may be
automatic, or it may be a matter of being
wretchedly difficult to edit.
If you browse the recent "Signature Bug
Testing" thread, you can see where I
deliberately tried to top-post from
cycling forums and the post appeared
normally in rec.bicycles.tech, but
top-posted through cycling forums.
There is a strange tendency to demand
that everyone else format, attribute,
insert, edit, snip, include, and possibly
sneeze according to our tastes. It would
be nice if Jim's posts showed who said
what more clearly, but it's hardly a
question of courage--he's not trying to
hide who says what.
As a lapsed English teacher, I find it
amusing how often the fussiest people
have no idea what they look like through
other software and on other servers (not
you, lest I be misunderstood---your stuff
seems normal to me).
Out of curiosity, do Peter Chisholm's
posts look a bit different on your screen?
I've never noticed anyone complaining,
but posts from Qui si parla Campagnolo
always show up as strangely formatted on
my software.
(And again, lest I be misunderstood,
I'm not suggesting that Peter should imitate
my peculiar formatting, much less join me in
swearing off the use of semi-colons, a perfectly
respectable form of punctuation that I don't
mind reading, but for some reason can no longer
bear to use.)
Carl Fogel
David Reuteler
: Possibly these differences in your software
: explain some of the differences in how
: attributions are being done? It may be
: automatic, or it may be a matter of being
: wretchedly difficult to edit.
doesn't matter. clear attributions are fundamental usenet etiquette. if
your software doesn't do it then you need to use software that does. this
is far more basic than even the top-posting vs bottom-posting debate where
there is some room for debate. there's none here. it's very bad form.
--
david reuteler
reut...@visi.com
jobst....@stanfordalumni.org
> The steerer tube is 1", small for a tandem these days. It might flex
> more as a result, but it's heavily reinforced through the length
> where the lower race mounts. (The frame builder added a several
> inches length of thick-wall tube into the steerer there.)
Unless the insert was brazed into the steertube over its full length,
it cannot add any strength to it. The only way to do that reasonably
is to start with a thick walled steel tube and to bore it out at the
upper end to accept a bar stem. Today you would need only to bore it
out far enough to retain the star washer to adjust the head bearing.
> The frame's head tube and fork's bearing seat were professionally
> reamed, faced and milled using Campy cutters before the headset was
> installed.
That makes no difference. As you see the roller complement slid off
to one side as they always do with this design and had most of its
load on the high side. Besides that, the rollers, being short and
loosely held, skew in their track and drag excessively. I experienced
all that and have a bearing that looks much like the one in your
picture.
> Nothing else I can think of, except that this was the first failure
> in an A9 of many I'd used on single bikes.
I think you'll find the others also have dimples and that this doesn't
make much difference because they skew to take up the clearance. It's
a grossly misbegotten design.
Jobst Brandt
jobst....@stanfordalumni.org
Gary Young
<snip>
>
> you're getting at false brinelling, right? the condition for that is
> that the races are loose and unloaded leading to sliding, not rolling.
Do you mind giving a source for that assertion? What I've read after a
quick Google search suggests that false brinelling can occur even when
the bearings are loaded (as when installed in machinery), as long as
they're not so heavily loaded that they're locked into place.
> unless the team mech hasn't tightened the forks properly, that's not
> what you get for a bunch of bikes bouncing around on the roof of a car.
> how many times have you taken the groceries home and found a can
> dented, an egg cracked or a bottle broken? you can't say these bikes
> are not being loaded!
No, of course not. But entirely beside the point.
Then if you hammer away at a race with a punch, as Jobst has
suggested, you should be able to replicate this effect, right? Have
you tried it?
>
> noone's forcing you or anyone else to read this stuff. if it doesn't
> interest you, fine. if you don't agree, fine. this is not religion,
> politics or health. we're here because we like bikes, right? hopefully
> that means we have something in common.
>
> jb
Here, class, we see the breakdown of the borderline personality when
its ego props are kicked out from under it. Where once he strode about
proudly, chest puffed out, defying anyone to challenge him, now he
regresses to the fetal position. "Don't hurt me. Please don't hurt
me," he cries.
jobst....@stanfordalumni.org
> Do you think it could have been initially tighter than the A9's used
> on your other bikes? Setting just past the point of play is easy
> enough but it's not so easy to judge freeness by the swinging test.
> Some other factors can influence how easily the forks/wheel swings:
> eg. cables, weight, exact test method, etc.
>> Subsequently I tried very fine adjustments several times as
>> symptoms began.
> It may have been too late by then.
Wait a minute! If tightness is assumed to be the cause, why would
adjusting clearance "too late" cause the bearing to wear more? This
isn't making sense. The problem is not with adjustment but rather the
basic design. Fretting does not rely on clearance, or for that
matter, load, as my dimpled upper Campagnolo Record bearings show. I
think the light weight (flexible) steer tube had the largest effect.
My bicycle is a prime subject with its long steer tube and it produces
plenty of failures until I got one of the new Shimano head sets.
Jobst Brandt
jobst....@stanfordalumni.org
Benjamin Lewis
> Tim McNamara wrote:
>> Atribute the text you're replying to the author. Your newsreader
>> should do this automatically (e.g., the attribution line above, which
>> is "jim beam <u...@ftc.gov> writes:"). You've made several attacking
>> posts which do not include the attributions- oddly enough, all of them
>> being text from posts by Jobst. Your last post, from which I took the
>> above text, had a correct attribution to me. If you're going to
>> attack someone, at least be honest and up front about who it is.
>
> etiquette? that's easily fixed and is different from cowardice.
> would have thought use of a threaded news reader made it obsolete.
Not at all; it's inconvenient to have to re-retrieve parent articles just
to see to whom one is replying, even if you ignore the problem of parents
expiring. It's a bit like posts that ask a question in the Subject: line,
and don't repeat it in the message body.
--
Benjamin Lewis
Mausoleum: The final and funniest folly of the rich.
-- Ambrose Bierce
ant
>
> > How long would it take for severe indexing to take place if a bent
> > steerer was the true cause?
>
> It probably would have little effect other than concentrating the
> fretting damage to the rear quadrant of the races because that is the
> only place the ball would bear after damaging the steertube. Usually
> only the fork blades bend on such collisions but the steertube also
> takes a slight bend.
>
> Often the kink in the system is only detected by the bicycle not
> riding straight ahead no-hands. I often see people riding such bent
> frames and when I ask them whether they can ride straight ahead
> no-hands, they look at me with disbelief that I would suggest doing
> something so stupid and dangerous as riding no-hands. The response is
> generally "I never ride no-hands!" with a tone of disgust.
thanks. IIRC, the fork was a cheap suspension fork, and the crash
resulted in a loose fit between steerer and crown. the bike got a new
headset and fork, and was unrideable with the damaged parts, so i
woudlnt have had a chance to check as you say, even if it had occurred
to me. the frame was straight and solid.
thanks for your time,
anthony
Tim McNamara
> When I peek through my Internet Exploder and Google Gropes to
> compare your "original format" with Jim, I notice that he uses
> Linux-Mozilla-Gecko, while you use Gnus and Emacs.
Emacs/Gnus (and all other standard Unix newsreaders) are designed with
awareness of the Usenet standards. Those standards have been in place
for many years, so surely the folks writing Mozilla do also.
Microsoft, I'm not so sure that they pay attention to any standards
but the ones they happen to control.
> Possibly these differences in your software explain some of the
> differences in how attributions are being done? It may be automatic,
> or it may be a matter of being wretchedly difficult to edit.
Perhaps. I haven't used Mozilla to read new in a long time, because I
don't like the interface. Gnus is much faster (slrn is faster yet).
My other usual newsreader is MT-NewsWatcher, which is a Mac-specific
newsreader unlike Gnus or Mozilla.
> If you browse the recent "Signature Bug Testing" thread, you can see
> where I deliberately tried to top-post from cycling forums and the
> post appeared normally in rec.bicycles.tech, but top-posted through
> cycling forums.
I didn't follow that thread; when posting through "cycling forums,"
whatever that is, is that through a Web interface that is somehow
gatewayed to Usenet?
> There is a strange tendency to demand that everyone else format,
> attribute, insert, edit, snip, include, and possibly sneeze
> according to our tastes. It would be nice if Jim's posts showed who
> said what more clearly, but it's hardly a question of courage--he's
> not trying to hide who says what.
I don't know if he is or isn't. It seemed , I dunno, questionable to
me that sometimes his posts include correct attributions and sometimes
they don't, and the ones that didn't also happened to be rather
vituperative.
> As a lapsed English teacher,
You seem to have a variety of talents!
> I find it amusing how often the fussiest people have no idea what
> they look like through other software and on other servers (not you,
> lest I be misunderstood---your stuff seems normal to me).
You are the first person in this newsgroup to accuse me of normalcy!
> Out of curiosity, do Peter Chisholm's posts look a bit different on
> your screen? I've never noticed anyone complaining, but posts from
> Qui si parla Campagnolo always show up as strangely formatted on my
> software.
Yes, Peter's and someone else's, I can't recall who. Instead of using
a quote string (e.g, starting each quoted line with an > or similar
character), their newreaders bracket <<quoted material>> in a
non-standard format. It does make the posts look odd, but I've gotten
used to it.
Tim McNamara
> Here, class, we see the breakdown of the borderline personality when
> its ego props are kicked out from under it. Where once he strode
> about proudly, chest puffed out, defying anyone to challenge him,
> now he regresses to the fetal position. "Don't hurt me. Please don't
> hurt me," he cries.
Geez. That was uncalled for. There's no eveidence of BPD. This
isn't sci.psychology.psychotherapy.
Donald Gillies
>>> I have a very old headset from someone else's bike that i'm interested
>>> in trying to restore (rather than discard).
>-snip-
>> it's not perfect, but remember seeing something on andy muzi's site about
>> his refinishing bearing races for customers with hard to replace
>> components. imo, that is your "least bad" technical solution. other
>> than being content with keeping it "as-is" and viewing it as an
>> interesting museum piece.
1. What do we think is the primary cause of indexing with 1" headsets --
a. faulty materials (e.g. non uniform steel alloys)
b. improper hardening of races (quenching or whatever is used) if so
is the hardening just on the surface or at depth in the races?
c. flexy steering tubes
d. improper lubrication practices
e. too much straight-ahead downhill riding / coasting + vibrations
f. crashes (my own experiences indicate crashes are not a problem)
2. It's a given that a bigger headset and different bearings can
reduce or delay the indexing problem.
3. If the problem is just (c), (d), or (e), can Andrew Muzi's headset
cutting tools be used to refinish bearing races ??
- Don Gillies
San Diego, CA
Chris B.
Pete Biggs
>>> Subsequently I tried very fine adjustments several times as
>>> symptoms began.
>
>> It may have been too late by then.
>
> Wait a minute! If tightness is assumed to be the cause, why would
> adjusting clearance "too late" cause the bearing to wear more? This
> isn't making sense.
Ok, assuming there was more wear. I suspect the real damage happened when
bearings were tighter than they needed to be.
> The problem is not with adjustment but rather the
> basic design. Fretting does not rely on clearance, or for that
> matter, load, as my dimpled upper Campagnolo Record bearings show. I
> think the light weight (flexible) steer tube had the largest effect.
There was no such wear or problems on the A9 bearings that I used for 10
times longer than Dianne's [I've now seen the photo]. Something must be
different . I probably ran mine with more clearance.
~PB, also with longer than average steer tubes (on 25" and 60cm bikes)
Pete Biggs
> As you see the roller complement slid off
> to one side as they always do with this design and had most of its
> load on the high side.
Stronglight's cartridge design should be better then as the roller cage
stays tight with the races, but the opposite was true in my experience.
~PB
Rick Onanian
wrote:
>Out of curiosity, do Peter Chisholm's
>posts look a bit different on your screen?
>I've never noticed anyone complaining,
>but posts from Qui si parla Campagnolo
>always show up as strangely formatted on
>my software.
We've complained a-plenty, and I bite my virtual tongue nearly every
day. Sometimes I write a reply and then cancel it instead of
sending it, realizing that I will only annoy Peter with more of the
same complaints.
I find his posts nearly impossible to read, between the bizarre
quoting, the somewhat weird formatting he writes with (for example,
he often ends his last sentence with a '-' instead of a '.'; this
leaves me expecting more), and the language cues of all the french
stuff I see littered all over his messages, which, despite my
conscious effort to ignore, trick my mind into expecting weirdness
that doesn't actually exist.
>(And again, lest I be misunderstood,
>I'm not suggesting that Peter should imitate
>my peculiar formatting, much less join me in
No, he should imitate mine. <G> Or, at least, use a quoting style
that somewhat resembles the standard, where a given character begins
every line of a quote. This results in many newsreaders
color-coding the quoted part, making it very easy to determine
what's written by whom and if it's new information. That is a good
thing because there's so much traffic on this newsfroup that a
message that can't be read quickly is a deleted message; and a
deleted message is one that may have had useful information in it.
>swearing off the use of semi-colons, a perfectly
>respectable form of punctuation that I don't
>mind reading, but for some reason can no longer
>bear to use.)
What, is there something wrong with semicolons? I find that they
are extremely useful; one example would be in sentences like this.
Of course, as a recovering english teacher, you can shoot holes in
my grammar. I have a peculiar mix of give-a-damns and
don't-give-a-damns which follows no known logic. Seemingly random
issues are addressed either by strict rule adherence, ignorance, or
careless stream-of-consciousness-gut-feeling writing. For example,
I very often abuse commas and semicolons in the elementary "where a
spoken pause might be found" sense, even if grammatically incorrect.
>Carl Fogel
--
Rick Onanian
jobst....@stanfordalumni.org
I think Gary sees it as I do. Jim Beam, aka:
http://www.internetwines.com/jimbeam.html
fits that description precisely. That this ploy is not apparent to
some readers strike me as they accuse me of being rude when I am curt
with someone posting BS and snide allusions. Mr. Whiskey has been
ding this for some time now.
Jobst Brandt
jobst....@stanfordalumni.org
Tim McNamara
> Tim McNamara writes:
>
>>> Here, class, we see the breakdown of the borderline personality
>>> when its ego props are kicked out from under it. Where once he
>>> strode about proudly, chest puffed out, defying anyone to
>>> challenge him, now he regresses to the fetal position. "Don't hurt
>>> me. Please don't hurt me," he cries.
>
>> Geez. That was uncalled for. There's no evidence of BPD. This
>> isn't sci.psychology.psychotherapy.
>
> I think Gary sees it as I do. Jim Beam, aka:
>
> http://www.internetwines.com/jimbeam.html
>
> fits that description precisely. That this ploy is not apparent to
> some readers strike me as they accuse me of being rude when I am
> curt with someone posting BS and snide allusions. Mr. Whiskey has
> been ding this for some time now.
I react, I suppose, as the psychologist that I am. Borderline
Personality Disorder is a serious and persistent mental illness,
which has caused suffering and disability for thousands.
http://www.nimh.nih.gov/publicat/bpd.cfm
Jim Beam, whomever he might be, may or may not have a mental illness.
He may just be one of those habitues of Usenet who keep their identity
hidden because they savor the ability to speak anonymously without
regard for the social niceties they have to maintain in their daily
lives. Or he may be a raging alcoholic whose tipple is Jim Beam. Or
his name might really *be* Jim Beam. Or he might- like about 2% of
the population- have BPD. Who knows?
However, calling him (or her, possibly) a borderline personality is
uncalled for IMHO. Calling him a git, twit or bullshit artist might
be rude but seems somehow less inappropriate to me. But that's coming
from a background of dealing with lots of folks with this disorder
from a clinical perspective. So be curt with him, point out the error
of his statements, etc. But diagnosing someone with a bona fide
mental illness, when one has never met the person, seems a bit off
somehow.
Matt O'Toole
> carl...@comcast.net (Carl Fogel) writes:
> > Out of curiosity, do Peter Chisholm's posts look a bit different on
> > your screen? I've never noticed anyone complaining, but posts from
> > Qui si parla Campagnolo always show up as strangely formatted on my
> > software.
>
> Yes, Peter's and someone else's, I can't recall who. Instead of using
> a quote string (e.g, starting each quoted line with an > or similar
> character), their newreaders bracket <<quoted material>> in a
> non-standard format. It does make the posts look odd, but I've gotten
> used to it.
This is the AOL newsreader's output. Unfortunately, you can't use anything but
AOL's software to read news on AOL. You can't connect to another news server
through AOL either -- they have it blocked.
That's OK, though. Peter is a pretty concise guy.
I'm well aware of the lousy appearance of some of my posts. Blame it on my
laziness in not weaning myself from Outlook Express.
Matt O.
A Muzi
>>>it's not perfect, but remember seeing something on andy muzi's site about
>>>his refinishing bearing races for customers with hard to replace
>>>components. imo, that is your "least bad" technical solution. other
>>>than being content with keeping it "as-is" and viewing it as an
>>>interesting museum piece.
>
>
Donald Gillies wrote:
> 3. If the problem is just (c), (d), or (e), can Andrew Muzi's headset
> cutting tools be used to refinish bearing races ??
Not for what a vintage headset costs. The only case for
regrinding a bearing surface is when the part is absolutely
unavailable and absolutely necessary for a restoration. PITA.
As we discussed, this is a common $200+ service on a $1000
engine crank but silly to most bicycle parts. The one time
I did was for the wife of the original importer on a
collectible all-original vintage bike where the part was
unobtainable.
If you are hellbent and money doesn't matter, every large
diesel engine rebuild house is set up to do it. My machine
shop instructor was the head guy at such a place many years ago.
jim beam
>
> I think Gary sees it as I do. Jim Beam, aka:
>
> http://www.internetwines.com/jimbeam.html
>
> fits that description precisely.
now, be honest, is that being curt or rude?
> That this ploy is not apparent to
> some readers strike me as they accuse me of being rude when I am curt
> with someone posting BS and snide allusions. Mr. Whiskey has been
> ding this for some time now.
and exactly what kind of a comment is that?
seriously jobst, if it were possible to have a grown-up dialog, without
the abuse, comparing our respective [and potentially complimentary]
knowledge pools, i'd be prepared to go there.
but i don't think i see that in you. looking back through the archives,
i see you repeatedly and blindly castigate [/some/ of your words]
"dorky" and "BS" innocents that dare to ask simple questions. even when
your response makes no sense and they rightly request clarification, you
fire back with tangential red-herrings effectively declaring that
the-emperor-is-fully-clothed-and-only-a-/fool/-would-ask-such-a-dumb-question-it's-so-obvious.
example: "ant" in this thread asks about indexing appearing after a
crash and you give an oblique response about how the fork will
mysteriously and suddenly "fret" because the head tube is bent. you
don't directly answer the question because you know it will take you
into the one subject of which you wish to avoid acknowledgement,
brinelling of bearings.
and to me you say: "take a cast-off head bearing that is not dimpled and
pound on it with a hammer and show us the shiny Brinell indentations.
You won't find any." tell me in all honesty, do you really want me to
do that? will you /really/ acknowledge the result when it does not
accord with your preconception? or will you just declare the bearing to
be somehow faulty, a mere fluke?
how about the way you dismiss timken's bearing failure information as
"an ancient text that no one has bothered to update". do you really
expect to be taken seriously?
/this/ is why people take issue with you jobst. you shamelessly bluster
for reasons i can only guess at. what is the payoff for you?
jb
jobst....@stanfordalumni.org
>>>> Here, class, we see the breakdown of the borderline personality
>>>> when its ego props are kicked out from under it. Where once he
>>>> strode about proudly, chest puffed out, defying anyone to
>>>> challenge him, now he regresses to the fetal position. "Don't
>>>> hurt me. Please don't hurt me," he cries.
>>> Geez. That was uncalled for. There's no evidence of BPD. This
>>> isn't sci.psychology.psychotherapy.
>> I think Gary sees it as I do. Jim Beam, aka:
>> http://www.internetwines.com/jimbeam.html
>> fits that description precisely. That this ploy is not apparent to
>> some readers strike me as they accuse me of being rude when I am
>> curt with someone posting BS and snide allusions. Mr. Whiskey has
>> been ding this for some time now.
> I react, I suppose, as the psychologist that I am. Borderline
> Personality Disorder is a serious and persistent mental illness,
> which has caused suffering and disability for thousands.
> http://www.nimh.nih.gov/publicat/bpd.cfm
I'm sorry, I wasn't aware of the technical definition behind the
"borderline..." (BPD) term. I just saw that Gary's comment describes
the behavior accurately in layman's terms. Jim Beam was on the
authoritative attack, full swing up to now, gaining so much hubris
that he went on to make even more absurd claims than before, ones that
were easily refutable. I did that, and he replies in a whimpering
"why are you attacking me" defense. His turnabout was striking to me.
That behavior is what I find appropriately characterized by Gary's
assessment. The tone of my technical response was aimed at Beam's
snide allusions to a petty and false analysis of the mechanical
failure that he made while dodging what was he found technically
inaccurate in my explanation of the tribological circumstances.
Jobst Brandt
jobst....@stanfordalumni.org
Tim McNamara
> I'm sorry, I wasn't aware of the technical definition behind the
> "borderline..." (BPD) term. I just saw that Gary's comment
> describes the behavior accurately in layman's terms. Jim Beam was
> on the authoritative attack, full swing up to now, gaining so much
> hubris that he went on to make even more absurd claims than before,
> ones that were easily refutable. I did that, and he replies in a
> whimpering "why are you attacking me" defense. His turnabout was
> striking to me.
Well, now, the *rest* of Gary's paragraph did seem pretty accurately
descriptive. Just not the BPD comment.
Tim McNamara
> "Tim McNamara" <tim...@bitstream.net> wrote in message
> news:m21xrma...@bitstream.net...
>
>> carl...@comcast.net (Carl Fogel) writes:
>
>> > Out of curiosity, do Peter Chisholm's posts look a bit different
>> > on your screen? I've never noticed anyone complaining, but posts
>> > from Qui si parla Campagnolo always show up as strangely
>> > formatted on my software.
>>
>> Yes, Peter's and someone else's, I can't recall who. Instead of
>> using a quote string (e.g, starting each quoted line with an > or
>> similar character), their newreaders bracket <<quoted material>> in
>> a non-standard format. It does make the posts look odd, but I've
>> gotten used to it.
>
> This is the AOL newsreader's output. Unfortunately, you can't use
> anything but AOL's software to read news on AOL. You can't connect
> to another news server through AOL either -- they have it blocked.
Well, though, I've seen other people post from AOL with "normal"
quoting. Is it a version issue? Or can one use Netscape with AOL?
carlfogel
Dear Rick,
I know of no objection to our friend the semi-colon and notice it no
more than any other fly-speck interposed between our tumbling thoughts.
A semi-colon enlivens smileys without giving me the slightest twinge.
But somehow I found myself using it less and less and finally admitted
that it had vanished from anything except source code. A stroke? Inbred
vice surfacing? A latent dislike for heroic couplets?
At the same time, I noticed another bizarre problem. I cannot bear to
break words with hyphens at the ends of lines, no matter how my various
word processors implore me to do so; yet hyphenation for format- ting
doesn't bother me in anyone else's writing.
(Pause to wipe beads of sweat from brow.)
I certainly would never tease anyone about their grammar, punctuation,
or spelling
amidst all the traffic in this
newsfroup.
Much less draw attention to it with a smiley. ;)
Incidentally, you might have a look at how your message appears when
viewed through cycling forums. It could give you some perspective on all
this formatting fuss.
Carl Fogel
--
Pete Biggs
>>> Subsequently I tried very fine adjustments several times as
>>> symptoms began.
>
>> It may have been too late by then.
>
> Wait a minute! If tightness is assumed to be the cause, why would
> adjusting clearance "too late" cause the bearing to wear more?
> This isn't making sense.
Yes it is. Too late because you can't undo the damage already done. Too
late because the damage has already ruined the races.
> The problem is not with adjustment but rather the
> basic design.
The basic design works if adjustment is correct - that means leaving some
clearance in for this A9 model. I suspect the headset was run too tight -
and I believe you like your headsets on the tight side also.
> Fretting does not rely on clearance
But does is help? In any case there was more than fretting going on with
the pictured headset and there are no such marks on my headset that has
done many more miles.
~PB
jobst....@stanfordalumni.org
>>>> Subsequently I tried very fine adjustments several times as
>>>> symptoms began.
>>> It may have been too late by then.
>> Wait a minute! If tightness is assumed to be the cause, why would
>> adjusting clearance "too late" cause the bearing to wear more?
>> This isn't making sense.
> Yes it is. Too late because you can't undo the damage already done.
> Too late because the damage has already ruined the races.
As I said, as soon as "damage" occurs there is clearance and further
damage should cease according to your scenario. This does not occur
as we see in the deep dimples that ultimately occurred on the tandem,
and incidentally on the failures I have observed on my own head sets
over the years.
> > The problem is not with adjustment but rather the basic design.
> The basic design works if adjustment is correct - that means leaving
> some clearance in for this A9 model. I suspect the headset was run
> too tight - and I believe you like your headsets on the tight side
> also.
Your suspicions are not supported by logical reality. Besides, people
who know how to adjust bearings have encountered these failures. What
you are saying is the old dodge, "you're doing it wrong" to all the
many people who have these failures. There are other parameters that
you are ignoring.
>> Fretting does not rely on clearance
> But does is help?
Help? No, it causes the damage. What are you talking about???
> In any case there was more than fretting going on with the pictured
> headset and there are no such marks on my headset that has done many
> more miles.
What size frame are you riding (the distance between lower and upper
head bearing)? I think that might shed some light on what you are
observing.
Jobst Brandt
jobst....@stanfordalumni.org
Mark Hickey
>and to me you say: "take a cast-off head bearing that is not dimpled and
>pound on it with a hammer and show us the shiny Brinell indentations.
>You won't find any." tell me in all honesty, do you really want me to
>do that? will you /really/ acknowledge the result when it does not
>accord with your preconception? or will you just declare the bearing to
>be somehow faulty, a mere fluke?
You'll never know until you actually do it. Why haven't you done so
if you're so sure of the outcome being at odds with Jobst's
prediction?
You can think Jobst is all bluff and bluster, but 99.9% of the time
he's right. And FWIW, he's more than willing to admit when he's
wrong. We once disagreed on another unrelated matter relating to
false brinelling of a headset, and he realized I was correct and was
quite gracious about admitting he was wrong.
And FWIW, that's not going to happen this time because he's right, and
you're wrong (like it or not).
Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $695 ti frame
Matt O'Toole
> Well, though, I've seen other people post from AOL with "normal"
> quoting. Is it a version issue? Or can one use Netscape with AOL?
I don't know about the latest version(s). Or previous ones. AFAIK, AOL has
always had some kind of proprietary news system, where the normal NNTP feed is
gated into whatever their thing is. So you can't access it with a normal NNTP
newsreader. Awhile back I was housesitting where my net access was an AOL DSL
line. I tried all the possibilities, called support, posted questions on
various help forums, etc., and this is what I found out. I wound up getting to
Usenet through a non-AOL dialup. Of course you can use a normal web browser
with AOL, so web-interfaced NNTP like Google would work fine. Maybe that's what
you saw.
To anyone who knows I'm wrong -- please correct me.
Matt O.
Rick Onanian
<usenet...@cyclingforums.com> wrote:
>At the same time, I noticed another bizarre problem. I cannot bear to
>break words with hyphens at the ends of lines, no matter how my various
>word processors implore me to do so; yet hyphenation for format- ting
>doesn't bother me in anyone else's writing.
I have that issue, too, but I also don't like it in others' writing.
There is no longer any excuse for it; we have word processors with
line wrapping and even justifying.
>I certainly would never tease anyone about their grammar, punctuation,
>or spelling
>
>amidst all the traffic in this
> newsfroup.
>Much less draw attention to it with a smiley. ;)
Heheh...I picked up that fun misspelling long ago, and never put it
down. Curiously, it's extremely rare that anybody says anything
about it. So far, this makes a total of _two_ times since I've
shown up in wreck.bicycles.*.
>Incidentally, you might have a look at how your message appears when
>viewed through cycling forums. It could give you some perspective on all
>this formatting fuss.
I will not use a web forum, sam I am
I will not use it in a boat
I will not use it on a goat
I will not use it in a house
I will not use it with a mouse
I will not use a web forum, sam I am
I will not drink it on the rocks
I will not use it near a fox
I will not even ask how
I will not compare it to a cow
I will not use a web forum, sam I am
I will not eat it whole
I will not kill a mole
I will not try to use that
Not even if asked by my cat
I will not use a web forum, sam I am
...etc.
Benjamin Lewis
> On 3 Dec 2003 17:37:02 +1050, carlfogel
> <usenet...@cyclingforums.com> wrote:
>> At the same time, I noticed another bizarre problem. I cannot bear to
>> break words with hyphens at the ends of lines, no matter how my various
>> word processors implore me to do so; yet hyphenation for format- ting
>> doesn't bother me in anyone else's writing.
>
> I have that issue, too, but I also don't like it in others' writing.
> There is no longer any excuse for it; we have word processors with
> line wrapping and even justifying.
It's still as necessary as it always was if you use block justification.
For example, look at pretty much any novel.
--
Benjamin Lewis
A small, but vocal, contingent even argues that tin is superior, but they
are held by most to be the lunatic fringe of Foil Deflector Beanie science.
Pete Biggs
>>> The problem is not with adjustment but rather the basic design.
>
>> The basic design works if adjustment is correct - that means leaving
>> some clearance in for this A9 model. I suspect the headset was run
>> too tight - and I believe you like your headsets on the tight side
>> also.
>
> Your suspicions are not supported by logical reality.
Not supported by your theories maybe; I don't think the full reality is
clear yet. My suspicions at least are consistent with actual reality in
my experience so far.
> Besides, people
> who know how to adjust bearings have encountered these failures. What
> you are saying is the old dodge, "you're doing it wrong" to all the
> many people who have these failures. There are other parameters that
> you are ignoring.
I'm not sure everyone who experiences failures realises how much clearance
the A9 requires - even if they are well experienced with normal ball
bearing types. Ok, that is a failure of the overall design because the
manufacture doesn't tell you that, etc, etc, but it doesn't mean the
hardware itself is useless.
Again, I never claimed that this is the best headset in the world in every
respect, just that it *can* work - and can work well, as it has done for
many people - look how many good reports and reviews it gets. It is fair
to criticise it if it can't cope with lots of preload or heavy duty usage
but that is different from saying it can't ever provide any good service -
which is what your original posts strongly implied to me. Such a total
dog would not still be popular after 20 years.
I'm not a fan of the "bicycles don't accelerate" style of statement. I do
understand the point of it, I just don't like it and I'm keen to correct
what I see as inaccuracies and bring out more of the truth. I think
making such broad generalisations is just as bad as any popular myth in
its own way.
>>> Fretting does not rely on clearance
>
>> But does is help?
>
> Help? No, it causes the damage. What are you talking about???
Please think about what I might be getting at. Of course I don't think
fretting could help. I mean: is fretting more likely to happen with an
over-tight headset than one with more clearance? It is generally accepted
by respected experienced mechanics that overtightening causes more
"indexing" problems with headsets than leaving a tiny bit of play in, and
my problems with notchy ball bearing types have reduced after slackening
them.
>> In any case there was more than fretting going on with the pictured
>> headset and there are no such marks on my headset that has done many
>> more miles.
>
> What size frame are you riding (the distance between lower and upper
> head bearing)? I think that might shed some light on what you are
> observing.
As I mentioned, I ride large frames. Head tubes I have used A9's on
measure 213mm (over 8"), 188mm and 185mm.
~PB
jobst....@stanfordalumni.org
>>>> The problem is not with adjustment but rather the basic design.
>>> The basic design works if adjustment is correct - that means
>>> leaving some clearance in for this A9 model. I suspect the
>>> headset was run too tight - and I believe you like your headsets
>>> on the tight side also.
>> Your suspicions are not supported by logical reality.
> Not supported by your theories maybe; I don't think the full reality
> is clear yet. My suspicions at least are consistent with actual
> reality in my experience so far.
I think I explained that if there is a depression developing, then
there is clearance and yet the depression continues to deepen.
Logically, if your hypothesis is correct about tight adjustment, then
these depressions should cease to deepen once formed. This is a
matter of 0.0001 inches, not a major change.
>> Besides, people who know how to adjust bearings have encountered
>> these failures. What you are saying is the old dodge, "you're
>> doing it wrong" to all the many people who have these failures.
>> There are other parameters that you are ignoring.
> I'm not sure everyone who experiences failures realises how much
> clearance the A9 requires - even if they are well experienced with
> normal ball bearing types. Ok, that is a failure of the overall
> design because the manufacture doesn't tell you that, etc, etc, but
> it doesn't mean the hardware itself is useless.
Let's not be so restrictive. All types of head bearings suffer these
failures, not just the A9 or rollers, but ball bearings as well. Your
suggestion is that it takes advanced learning top make them work.
That in itself is a design flaw if true... and I don't believe it is.
> Again, I never claimed that this is the best headset in the world in
> every respect, just that it *can* work - and can work well, as it
> has done for many people - look how many good reports and reviews it
> gets. It is fair to criticise it if it can't cope with lots of
> preload or heavy duty usage but that is different from saying it
> can't ever provide any good service - which is what your original
> posts strongly implied to me. Such a total dog would not still be
> popular after 20 years.
All sorts of equipment with marginal usefulness hangs around for a
long time in bicycling, the level of mechanical astuteness not being
what one might imagine. Just think how long bicycles survived without
knowing why spokes failed and what stress distributions in wheels are.
Practically every aspect covered in "the Bicycle Wheel" was unknown
and was severely challenged by those in the business when the book
first appeared. We still get long threads here on wreck.bike about it
even though engineering people have recognized and understood the
matter.
> I'm not a fan of the "bicycles don't accelerate" style of statement.
> I do understand the point of it, I just don't like it and I'm keen
> to correct what I see as inaccuracies and bring out more of the
> truth. I think making such broad generalisations is just as bad as
> any popular myth in its own way.
I see you have some bad baggage lurking around. If you feel strongly
about bicycle acceleration, how about giving some data and examples of
significant acceleration once a bicycle is underway. Pleas do this
under a new heading.
>>>> Fretting does not rely on clearance
>>> But does is help?
>> Help? No, it causes the damage. What are you talking about???
> Please think about what I might be getting at. Of course I don't
> think fretting could help. I mean: is fretting more likely to
> happen with an over-tight headset than one with more clearance? It
> is generally accepted by respected experienced mechanics that
> overtightening causes more "indexing" problems with headsets than
> leaving a tiny bit of play in, and my problems with notchy ball
> bearing types have reduced after slackening them.
I don't believe you understand what fretting is and how it works. It
is entirely independent of preload. As I pointed out, I have
Campagnolo upper races that are indented. Your experience, judging
from your reports given here, is probably not adequately controlled to
isolate load as a factor. The tandem example showed that flexing of
the steertube is the likely cause of that failure. I think that if
the picture shoed the running surface of the top bearing, it to would
show fretting damage.
>>> In any case there was more than fretting going on with the
>>> pictured headset and there are no such marks on my headset that
>>> has done many more miles.
>> What size frame are you riding (the distance between lower and
>> upper head bearing)? I think that might shed some light on what
>> you are observing.
> As I mentioned, I ride large frames. Head tubes I have used A9's on
> measure 213mm (over 8"), 188mm and 185mm.
That should be enough to cause fretting unless the steer tube is
either unusually thick or large in diameter.
Jobst Brandt
jobst....@stanfordalumni.org
Pete Biggs
>> I'm not a fan of the "bicycles don't accelerate" style of statement.
>> I do understand the point of it, I just don't like it and I'm keen
>> to correct what I see as inaccuracies and bring out more of the
>> truth. I think making such broad generalisations is just as bad as
>> any popular myth in its own way.
>
> I see you have some bad baggage lurking around. If you feel strongly
> about bicycle acceleration, how about giving some data and examples of
> significant acceleration once a bicycle is underway. Pleas do this
> under a new heading.
No I don't feel so strongly about acceleration that I want to start a new
thread on it now - especially after you've now added the subjective word
"significant" (I agree that it's not significant if you mean more than a
very few seconds at a time from a strong rider and that the speed ranges
are small compared to motor vehicles).
It's just the wonderful example that will always stick in my mind of you
making an exaggerated statement that is so obviously untrue in itself to
make a point. You did actually once simply write: "Bicycles don't
accelerate". Let's face it, that ain't true (unless we mean bicycles
without a rider). Sorry I can't promise not to quote it out of context
again - because I love it, in a perverse kind of way.
I understand the need to keep things concise (and I admit that I'm poor at
it) but feel you sometimes go to far too far and therefore make it
difficult to understand the reality - which is not so black and white.
There is room on this newsgroup for fuller explanations (in terms the
average r.b.t reader can understand).
Thank you for the rest of your reply. I'm still not convinced so I'll
have to read up more on fretting, steerer flex/movement and what other
factors can damage headsets.
/snip
>> As I mentioned, I ride large frames. Head tubes I have used A9's on
>> measure 213mm (over 8"), 188mm and 185mm.
>
> That should be enough to cause fretting unless the steer tube is
> either unusually thick or large in diameter.
All 1".
~PB
Pete Biggs
> I think I explained that if there is a depression developing, then
> there is clearance and yet the depression continues to deepen.
At the same rate?
> Logically, if your hypothesis is correct about tight adjustment, then
> these depressions should cease to deepen once formed. This is a
> matter of 0.0001 inches, not a major change.
My logic would be sound if there was more than one cause for the
depressions (different forces having similar results), or if there was
*some* significant pressure on the bearings for some of the time even when
there was clearance when tested.
I'll accept depression can continue even with clearance if that's what you
have found, but in practice users often repeatedly readjust their headsets
as clearance occurs, so applying more load.
Is there any compression when headset is preloaded? I'm wondering if
clearance does occur immediately after the depression starts to develop or
if the loading would continue to cause further accelerated depression for
a while before clearance occurs?
~PB
Pete Biggs
>>> As I mentioned, I ride large frames. Head tubes I have used A9's on
>>> measure 213mm (over 8"), 188mm and 185mm.
>>
>> That should be enough to cause fretting unless the steer tube is
>> either unusually thick or large in diameter.
>
> All 1".
Not unusually thick either.
~PB