How long should a rim last with rim brakes?
Andre Jute
ali rim, used in wet but clean conditions, no salt, Magura hydraulic
rim brakes with standard black pads. I need to know if I should keep
on on standby. My annual distance is about 2600km/1600m.
Andre Jute
I'm not a know-all. I don't need to be. I know who to ask.
thirty-six
The rim should last until it splits. Honest.
Norman
> How many miles should a rim last with rim brakes? I'm talking about an
> ali rim, used in wet but clean conditions, no salt, Magura hydraulic
> rim brakes with standard black pads. I need to know if I should keep
> on on standby. My annual distance is about 2600km/1600m.
>
Brake use varies: I rarely use the brake while riding,
even with a freewheel. I've ridden with people who
brake all of the time for no good reason without the
least warning.
Also, I have never worn a rim out that way: they all die
from whanging on expansion joints or turn into tacos
from playing too hard off-road. (this is not very true, I
get blind drunk and barrel into ravines in the middle
of the night and then have to walk 6 miles home, in
the rain, bleeding)
Clive George
news:729b8d16-a0c1-4f69...@13g2000prl.googlegroups.com...
> How many miles should a rim last with rim brakes? I'm talking about an
> ali rim, used in wet but clean conditions, no salt, Magura hydraulic
> rim brakes with standard black pads. I need to know if I should keep
> on on standby. My annual distance is about 2600km/1600m.
Massively variable, but it's easy enough to have a spare anyway. 'course
being able to fit it yourself means the spare is all you need.
datakoll
in rain on roads in silica territory. Brake surfaces wore thin.
Andre Jute
> 3000-3500 miles ? Sunrims double wall. Concientiously Cleaned but run
> in rain on roads in silica territory. Brake surfaces wore thin.
Hokkay, this is useful information at last. Fangs!
I'd cry if my rims needed replacing after so few miles...
Being slow on the uptake on Thursdays, it only just occurred to me
that the manufacturers of my Utopia, who give copious information
(hundreds of pages in the catalogue, discussion booklet for aspiring
owners and handbook, plus a lively netsite) and test every component
to destruction, might have something to say, and so it turned out.
They reckon those particular rims (Exal XL25 designed and made
specifically to their desires to have a long-lasting wheel) should
last 15,000 to 25,000km.
Fair enough. I should hope to be at the high end of this, which would
be nine to eleven years away, but even at the short end, I'm still
five or six years from having to rebuild a wheel.
I don't even think it is worth getting a set of spare rims (one 36
front and one 32 rear for the Rohloff HGB) for an event that far into
the future. Maybe when the time comes, I'll try Chalo's fave of those
Kris Holm monocycle rims, which are 25 per cent wider even than the
Exal XL25s.
Lou Holtman
If you don't brake forever ;-)
I have rims on one of my road bikes that have 25000 km on them and are
half through. On one of my ATB's (wordt case conditions) they lasted for
about 6000 km.
Now I have ceramic rims on my rim brake Rohloff ATB. After 800 km they
look as new. They are 2 times more expensive though.
Lou
Bernhard Agthe
Andre Jute wrote:
> How many miles should a rim last with rim brakes? I'm talking about an
> ali rim, used in wet but clean conditions, no salt, Magura hydraulic
> rim brakes with standard black pads. I need to know if I should keep
> on on standby. My annual distance is about 2600km/1600m.
Basically a rim should last you anywhere from five to ten years, but
that does vary with brake use and with the type of brake pads you have -
there used to be some Shimano ones available that eroded a 5mm-wide
section of the rim away quickly - but they are known to collect Alu bits...
With my Magura brakes I didn't have to replace a rim yet - after 12.000
km. But I did have to replace one because it had a bump in it (hit a
block of wood at 30km/h) and I replaced a complete wheel because the
axle was worn and replacing the rim would have cost more than the new
wheel (even with all the extras I wanted). The replacement wheel has a
very boxy high rim which allows me to move the brake pads inwards so
they run on the hollow part of the rim (and are safe from minor bumps on
the outside ;-)
Go figure ;-)
Ciao...
Graham
"Andre Jute" <fiul...@yahoo.com> wrote in message
news:729b8d16-a0c1-4f69...@13g2000prl.googlegroups.com...
> ali rim, used in wet but clean conditions, no salt, Magura hydraulic
> rim brakes with standard black pads. I need to know if I should keep
> on on standby. My annual distance is about 2600km/1600m.
I have two sets of Open Pros (like em or hate em!) one with
16,000m/25,700kms and one with 11,000m/17,700kms and both sets look to be
still OK and both have remained true since built. I am no feather weight I
guess at 182lbs/83kgs. Most of my riding is out of town on country roads so
braking is minimal. I guess urban riding would make a significant
difference.
Graham.
pdlamb
20,000 miles or so on the front, and still going. The bearings on the
rear were shot before I figured I needed to repack them occasionally,
so I built a whole new wheel. Probably have 6,000 mi. or so on each
of two different rears on that bike and 8,000 on another one before it
was replaced (along with most of the rest of the bike under warrantee
-- I love REI!). No hydraulics in sight, but I've worn out a couple
sets of Kool-stop Salmon pads.
I imagine you could chew up a rim in a few thousand miles riding in
mud/dirt/sand with Shimano pads, if you could stand the racket!
N8N
I dunno about Yurrup but over her eit seems that mfgrs. do not expect
you to ride your bike in the rain.
I took about a 30 mile ride in the rain a few weeks back because I was
getting stir crazy and had a noticeable amount of rim wear just from
that one ride. I immediately purchased a set of KS salmons. (have
not received/fitted them yet however.)
nate
Simon Lewis
Are you related to Bill Baka?
How often did you apply your brakes on this 30 mile ride?
thirty-six
I get it. Y'all have your rims wearing out have your pads too close.
I ride through sand and mud and don't generally use my brakes.
Another thing is I inspect the pads for contamination, usually just by
releasing the QR at the handlebars. If you are picking up grit and it
is rubbing then open your brake calipers to prevent uneccesary wear.
Brake lever QR is good because maximum braking force is retained.
Or are modern rims made of butter and brake pads of diamond grit?
N8N
Not that I know...
> How often did you apply your brakes on this 30 mile ride?
At some points during the ride, every block :(
not too many places that I can ride where I can completely avoid
traffic control devices...
nate
landotter
I used Tektro and Avid shite last year after I built some non-machined
rims in the spring. They did a great job "machining" the rim. I put a
plain old KS Eagle 2 blacks on the front this spring. The pads are
still 90% good, and the rims are happy. I got three years out of a
set once! Non-KS shoes last me 3-4 months in the city. Salmon, red,
black, green, grey--they're all good.
N8N
Actually my pads currently are Eagle 2 black. No noticeable brake
track thickness reduction, but my front rim went from smooth to
grooved in about 30 miles.
I am thinking of using the KS "cross pads" because if I understand it
correctly those are cantilever style holders for Dura-Ace inserts,
therefore I can use salmon inserts, and also they appear to be shorter
than the Eagle 2s so I could open my front brakes all the way for a
quick hose down after a dirty ride. (rear edge of the Eagle 2s hits
on the fork.) I ordered a set of salmon Eagle 2's before I figured
that out, but I ended up receiving threaded style pads and I need
smooth stud.
nate
thirty-six
So do manufacturers fit abrasive pads to make up for mechanical
inadequacies of the braking system or user? Or even the operatiion
of the brake lever. It is OK to pull harder in the wet, you know.
It's called feedback. For example "Yikes, I'm gonna crash", thinks"
pull harder", "ooh, that did it". "I'm OK" "it's my magic foam cap
working again".
Bill Sornson
> N8N <njn...@hotmail.com> writes:
{snippage}
>> I took about a 30 mile ride in the rain a few weeks back because I
>> was getting stir crazy and had a noticeable amount of rim wear just
>> from that one ride. I immediately purchased a set of KS salmons.
>> (have not received/fitted them yet however.)
>> nate
> Are you related to Bill Baka?
> How often did you apply your brakes on this 30 mile ride?
In fairness, a jillion years ago I did a mtb ride at Nobel Canyon (very
"technical" just for Jute) that turned into a snowy, gritty death roll. My
(V-)brake pads literally wore down to the holders on the descent. Frozen,
numb fingers squeezing the levers to the bar and barely slowing the bike
was...well, adventuresome.
And now I see that Nate mentioned RIM wear*, not pad.
Never mind...
BS
*My old rims wore to concavity (?) and severe brake surface thinness more
than once, but can't pinpoint any single rides that did it. Dirty snow not
helpful.
landotter
I'm not aware of the cartridge style being available in a shorter
length with smooth post other than these VOs:
http://www.velo-orange.com/voadbrsh.html
Which I believe use Shimano road-compatible carts, usually the easiest
KS product to find, in these parts at least.
Most canti and LP brake shoes take the longer style made popular with
direct pull brakes:
http://www.velo-orange.com/vosqfrbrshan.html
EDIT: A quick search showed a few different smooth post with road size
cart--with inflated speshul cxcross pricing. The VO stuff seems like
the best deal going--or Tektro if you want the longer holders.
N8N
hey, thanks, those are $10 less than the Kool Stops and the angle
adjustment might be handy.
nate
landotter
Can't vouch for the included inserts, but if they suck--KS ones are
only $10. ;-)
datakoll
yawl know rain riding right ? wetness picksup sand grit spreads over
lower bike during useage not after ride cleanups. that's it. wore
right thru.
Andre Jute
delight in riding in it, it is probably worth mentioning Rigida's CSS
rims. When I was speccing up my Utopia, I considered the Rigida
Grizzly (which Utopia offers as an alternative to the Exal XL25) but
it isn't wide enough to be comfortable with the 60mm Big Apples were
more important to me.
Here's the story on Rigida's CSS-treated rims: "Ultra hard wearing
Carbide Super Sonic brake surface, allowing fantastic braking and wear
characteristics. The carbide is projected at seven times the speed of
sound on to the rim embedding it into the alloy. Unlike a ceramic
surface it cannot flake away as it is part of the rim (not a layer).
The only recommended brake blocks are Swisstop C.S.S. Blue V brake
blocks.”
That last bit is very likely out of date. Koolstop also makes a
suitable brake block, and for those fortunate enough to have Magura
hydraulic rim brakes, the grey blocks are also said to work and last
well with the Rigida CSS rims.
Let me stress that, while I do have Rigida rims and have found them
good, I have no experience of the CSS type or the brake blocks
suitable for it; that's all hearsay.
Andre Jute
"Cycling wisdom" is an oxymoron
Andre Jute
Unless yawl live innadah tropics yawl know nuffink of rain. This arvo
the rain on the street in front of my house washed away the new
tarmacadam around a manhole cover they put in on Monday.
Andre Jute
One shortcut to the divorce courts is using a Porthault towel off the
top of the downstairs laundry cupboard stack to wipe down your bike...
N8N
That was kind of my reasoning behind being attracted to a Dura-Ace
format holder - besides hopefully clearing my fork, if I decide I
don't like the pad compound, ASSuming my brakes aren't too worn, I can
just buy another set of inserts and change them without even
readjusting my brakes, and for cheap.
nate
Andre Jute
> Simon Lewis wrote:
Snow? What's that? You musta made it up. Sorni. Here on the Costa del
Tax Exile we know everything, so I asked a man who stopped his Roller
next to me to admire my new bike, "What's snow?" He said, "Y'know,
when you go skiing, it's what the poor Swiss gnomes live in, that
white stuff underfoot. They spread it when the skiers don't want it
anymore." He's the lead singer of a famous rocknroll band and a telly
pundit on the war on hunger in Africa, so yawl can bet he knows what
he's talking about. Anyhow, his girlfriend assured me, "Snow doesn't
grow anywhere except in cuckoo-land. Not the real stuff anyhow."
So there you are.
Andre Jute
17 degrees Celsius on 30 October -- Global Warming is doing some good
at last!
Andre Jute
Nah, I have clean rain. This is good news. Thanks. -- Andre Jute
Andre Jute
wrote:
> "Andre Jute" <fiult...@yahoo.com> wrote in message
Even less of a featherweight at around 210-215 pounds, and rising a
great big touring bike with the biggest Big Apples. But my riding
milieu is the same as yours: clean roads -- cow dung more likely than
mud -- and clean rain, no salt, little traffic. I'm starting feel less
exposed to big bills on short notice already. -- Andre Jute
Andre Jute
This is good, Bernhard, cos I bet your roads throw up more rubbish
than mine, and you use your bike more and harder than I use mine. I'll
inspect my rims in daylight tomorrow to try and gauge how much wear in
the 2000km they've done, but I've just about given up the idea of
bothering to keep spare rims.
Andre Jute
A little inaccuracy sometimes saves tons of explanation. --H.H.Munro
("Saki")(1870-1916)
Visit Jute on Amps at http://members.lycos.co.uk/fiultra/
"wonderfully well written and reasoned information
for the tube audio constructor"
John Broskie TubeCAD & GlassWare
"an unbelievably comprehensive web site
containing vital gems of wisdom"
Stuart Perry Hi-Fi News & Record Review
Andre Jute
For 50,000km on my sort of roads they might be worth double. Which
brand ceramic rims did you get? -- Andre Jute
Lou Holtman
The Rigida CSS Grizzly's you mentioned.
On my Magura rimbrake-bike I run them at the moment with the grey
blocks. They came with the bike and braking is great. I ordered a spare
set specific for ceramic rims and they are green(ish). On another bike
with V brakes I use the KS pads and they are also green(ish). First I
used the standard black pads and they wore very fast but braking was
excellent.
Lou
Jobst Brandt
> How many miles should a rim last with rim brakes? I'm talking about
> an ali rim, used in wet but clean conditions, no salt, Magura
> hydraulic rim brakes with standard black pads. I need to know if I
> should keep on on standby. My annual distance is about
> 2600km/1600m.
> Andre Jute I'm not a know-all. I don't need to be. I know who to
> ask.
I hope you also know whom to ask, or as Ernest Hemingway said in your
reading: "For WHO the bell tolls."
As for rims (what is ali?), the wear rate is determined by abrasives
in the brake-pad-to-rim interface. This effect is greatest when
riding on paved wet mountain roads. Of course descending wet dirt
roads can cause even faster wear, but then I don't know many fast road
bicycle descenders on wet dirt roads.
Jobst Brandt
AMuzi
"what is ali? "
Ali is The Greatest of course:
http://www.artafterdark.com/muhammadali_mini.htm
'float like a butterfly, sting like a bee'
--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971
Andre Jute
> Andre Jute wrote:
> > How many miles should a rim last with rim brakes? I'm talking about
> > an ali rim, used in wet but clean conditions, no salt, Magura
> > hydraulic rim brakes with standard black pads. I need to know if I
> > should keep on on standby. My annual distance is about
> > 2600km/1600m.
> > Andre Jute I'm not a know-all. I don't need to be. I know who to
> > ask.
>
> I hope you also know whom to ask, or as Ernest Hemingway said in your
> reading: "For WHO the bell tolls."
Poor Jobst, you're the only guy I know who has absolutely zero street
cred. It's the vernacular, my man. Get with it.
> As for rims (what is ali?), the wear rate is determined by abrasives
> in the brake-pad-to-rim interface. This effect is greatest when
> riding on paved wet mountain roads.
Mmm. I hope you're wrong, because I do fast descents on tarmac every
time I go out.
>Of course descending wet dirt
> roads can cause even faster wear, but then I don't know many fast road
> bicycle descenders on wet dirt roads.
Oh dear. I've been eyeing a gravel road down a steep hill on a private
estate for a thrill before I give my bike its annual wash'n'wax.
Andre Jute
Visit Andre's books at
http://www.audio-talk.co.uk/fiultra/THE%20WRITER'S%20HOUSE.html
Andre Jute
Sometimes I think Jobst entirely missed the second half of the
twentieth century. Hey, Jobst, I can get a grant if you'll leave me
your brain to study.
> --
> Andrew Muzi
> <www.yellowjersey.org/>
> Open every day since 1 April, 1971
Andre Jute
Just shooting through to Lapaloosa -- Granddad Simpson
Marcin J.
Corratec pads, all weather, city, smooth/medium terrain:
rear - 5000 km,
front - 10000 km and is still alive.
--
Cheers
marcin
Brian Huntley
> As for rims (what is ali?), the wear rate is determined by abrasives
> in the brake-pad-to-rim interface. This effect is greatest when
> riding on paved wet mountain roads. Of course descending wet dirt
> roads can cause even faster wear, but then I don't know many fast road
> bicycle descenders on wet dirt roads.
Stop and go in rainy/snowy/salty conditions isn't all that great for
rims, either. I got about 20,000 km on a rear CR18 before visible
cracks on the braking surface opened up, and I mainly use the front
brake. The front rim will probably not last to 25k km.
Note this bike carries heavy loads as a commuter/shopper/tourer, and I
wasn't able to use "salmon" pads on it due to local unavailability in
the required size (V-brake style pads on cantilevers.) I've since
switched out the rear brake to a more standard one, partially so as to
go back to salmons.
thirty-six
It is because of the changing nature of a bike rim with brake wear
that what may be deemed acceptable spoke tension with a new rim is not
necessarily acceptable as it wears. The rim becomes thinner and will
distort more with high spoke tension from thin spokes, and with riding
load.
Andre Jute
Why does your rear rim wear out first? -- AJ
Andre Jute
So what we're getting down to is that the brake blocks have a major
influence (in addition to the obvious influences like road salt eating
ali). The manufacturer of my bike give a very strong recommendation to
use only the black Magura pads; they go as far as to say the other
pads will significantly cut rim life. -- AJ
Clive George
news:f95190f2-65f7-4a15...@y10g2000prg.googlegroups.com...
>So what we're getting down to is that the brake blocks have a major
>influence (in addition to the obvious influences like road salt eating
>ali). The manufacturer of my bike give a very strong recommendation to
>use only the black Magura pads; they go as far as to say the other
>pads will significantly cut rim life. -- AJ
The grey and green ones definitely will - they're designed for use on
ceramic coated rims.
The pink ones are kool-stop salmon compound. Not sure how they compare with
the blacks for rim wear.
thirty-six
> "Andre Jute" <fiult...@yahoo.com> wrote in message
Fibrax now make the old X pattern by Weinmann, doesn't seem as hard as
the the Weinmann blocks were. Still seems to stop as well. Anyone
else use these and their long term experience?
Bill Sornson
Aversion to endos.
Clive George
news:c17a75c5-5326-4154...@l13g2000yqb.googlegroups.com...
> Fibrax now make the old X pattern by Weinmann, doesn't seem as hard as
> the the Weinmann blocks were. Still seems to stop as well. Anyone
> else use these and their long term experience?
For Maguras?
thirty-six
> "thirty-six" <thirty-...@live.co.uk> wrote in message
Uh? Am I not paying attention?
thirty-six
Do you use an anchor for quick stops?
Bill Sornson
Next time think before you post.
HTH!
Nate Nagel
It was a valid question; you can't stop nearly as fast on the back brake
as you can with the front. Stopping using primarily the front brake is
good practice as it educates you hand as to how the front responds, when
you really need it for a panic stop.
nate
--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel
Bill Sornson
> Bill Sornson wrote:
>> thirty-six wrote:
>>> On 1 Nov, 19:54, "Bill Sornson" <so...@noyb.com> wrote:
>>>> Andre Jute wrote:
>>>>> On Nov 1, 12:42 pm, "Marcin J." <xc-ri...@wp.pl> wrote:
>>>>>> Cheap Al rims without special braking surfaces, most of the time
>>>>>> with yellow Corratec pads, all weather, city, smooth/medium
>>>>>> terrain: rear - 5000 km,
>>>>>> front - 10000 km and is still alive.
>>>>> Why does your rear rim wear out first? -- AJ
>>>> Aversion to endos.
>>> Do you use an anchor for quick stops?
>> Next time think before you post.
> It was a valid question; you can't stop nearly as fast on the back
> brake as you can with the front. Stopping using primarily the front
> brake is good practice as it educates you hand as to how the front
> responds, when you really need it for a panic stop.
Now try reading the THREAD. (Hint: braking more with the rear does not
mean never using the front. HTH.)
Nate Nagel
Peter Cole
I almost never use a rear brake. My fixer doesn't even have one. The
rear brake is only of any use in really slippery conditions or long
braking descents.
Bill Sornson
I'll type this slowly and then I'm done.
Andre asked why someone's rear rim wears out faster than the front. I
replied because endos are not fun. "36" then asked if I use an anchor for
quick stops -- a complete non-sequitur. Of course I grab a handful of
brake -- front and rear -- in must-stop-now scenarios. But if I "panic
squeeze" the front I'm asking for trouble.
It's less true of road bikes than mountain, but generally one uses the rear
brake more than the front -- if for no other reason than that the forces on
the front wheel are considerably higher. That is why people's rear pads and
rims will /generally/ wear out faster than their fronts. No anchors
involved.
One last time: HTH.
BS (out)
Nate Nagel
No, one does not "generally use the rear brake more than the front" save
for special cases like descending a hill (especially in low-traction
situations.) In a true panic stop you use the front brake ONLY so it
makes sense to use the front brake for general stopping so it becomes
reflexive.
nate
thirty-six
>
> No, one does not "generally use the rear brake more than the front" save
> for special cases like descending a hill (especially in low-traction
> situations.) In a true panic stop you use the front brake ONLY so it
> makes sense to use the front brake for general stopping so it becomes
> reflexive.
I grab both together, hard, then modulate. Releasing the rear to stop
the skid and releasing the front to prevent rear tyre lift. When
sliding on gravel I find it OK to keep the wheels locked(just, ready
for immediate release) with exagerrated steering movements. I ride
two bikes with left front for one and right front for the other. I do
a hard stop only fifty yards from my door just to lodge in the correct
response. I sometimes dont get it right first time and do skid the
rear a little long. it only takes a moment to start again and then my
brain braking mode i sset for the ride. I leave space for this error,
but there is usually a dire need to stop. I make sure that somewhere
else in the ride I do a hard stop, usually going downhill. I'll do
this even if wet. If i get back to my door and realise I havn't done
a hard stop, then I
'll doo it for my last stop.
If I'm riding with company who is experienced, I will ride rubbing
shoulders and knuckles. But the difficult skill is 'borrowing' a
bottle from the frame mountings. Legs tend to get in the way,
particularly if the rider likes to spin.
Same as I'll always make sure I do a forced turn, a bunnyhop (when I
remember), out of the saddle riding, and riding no hands for 100 yards
(if safe).
pm
My rear rims and pads outlast the front by a factor of 2 to 4, as do
most competent (road) riders.
Because I am used to braking with the front to I am able to brake up
to and including the point of lofting the rear wheel (seated, with
panniers on) and have done so more than once in emergency stops, but
have never endoed.
"I find this lever difficult to control, therefore I will only use it
in emergencies where I need an instinctive reaction" is among the
least adroit pieces of reasoning a bicyclist can make.
-pm
Brian Huntley
I think you misread my posting. My rim did not crack around the spokes
- they were fine. The braking surfaces (sides) of the rim wore
through.
I happen to have taken a photo:
http://www.crazyguyonabike.com/doc/page/pic/?o=RrzKj&pic_id=426142&v=1w&size=large
Andre Jute
> It's less true of road bikes than mountain, but generally one uses the rear
> brake more than the front -- if for no other reason than that the forces on
> the front wheel are considerably higher. That is why people's rear pads and
> rims will /generally/ wear out faster than their fronts.
I have a hard time believing that any cyclist wears out a rear rim
faster than a front one because he brakes more on the back. Simple
consideration of the relative retardation of front and rear brakes
will tell you that for anything but gentle commuting that is unlikely.
I was in fact expecting an explanation about the back wheel being more
highly loaded by either the rider and luggage weight or by the driving
forces.
All the same, I wouldn't dream of riding with only a front brake. Too
much slippery cow dung on some of my downhills; when you get into the
shit and you cannot avoid braking, you need to have control of both
wheels if you're not to take a spill.
Andre Jute
http://www.audio-talk.co.uk/fiultra/Andre%20Jute's%20Utopia%20Kranich.pdf
thirty-six
I didn't misread. I find the use of the term crack to be misleading,
I decided to play it as a crack (not open) and not a split (or hole)
for which I expected you really meant. Why use such a misleading
term? You know what you mean. I had to guess on that there was
nothing else to suggest it anything but a split caused by brake wear.
thirty-six
What a pile of shite. If you brake on sloppy dung, you go down. If
you corner on dung, you go down. If you sneeze when riding through
dung, you go down. You have to ride around it to be safe. If you
can ride through it fast enough, then it is possible to sneeze withou
falling into the shite.
Bill Sornson
> On Nov 1, 11:48 pm, "Bill Sornson" <so...@noyb.com> wrote:
>
>> It's less true of road bikes than mountain, but generally one uses
>> the rear brake more than the front -- if for no other reason than
>> that the forces on the front wheel are considerably higher. That is
>> why people's rear pads and rims will /generally/ wear out faster
>> than their fronts.
>
> I have a hard time believing that any cyclist wears out a rear rim
> faster than a front one because he brakes more on the back.
When I was learning to mountain bike, it was drummed into me to use a lot
more rear brake than front. (70-30 was pretty close.) Whole idea was to
equalize the braking forces on both wheels. Since the front naturally draws
the most force (due to gravity and inertia), grabbing too much lever will
throw you over or cause loss of control. Grabbing too much rear (pardon the
expression) only causes skidding -- not cool on trails, of course, but not
generally dangerous. So you brake the rear wheel firmly and baby the front
to maintain control AND stop/slow quickly and predictably. Rear rim gets a
LOT more braking action and -- hard to believe -- wears out faster.
Granted, on road bikes (with drop bars at least) the center of gravity is
different, but the same forces apply. Gotta grab a whole lot more rear to
balance out the front. (Rim wear not as profoundly different though.)
Bill "and I STILL don't need no stinkin' anchor" S.
Dan O
Andre Jute
Okay, now I get it. And when you add wet and mud, all becomes clear,
as in a reference Danno sent, which I reproduce below. Thanks Bill,
Dan, all who contributed. -- Andre Jute
******
Oivind Toien writes:
> My question is: My rear brake pads tend to wear 2-3 times as fast at
> those at the front. I have some difficulty beleaving that this only is
> due to more dirt on the rear rim, or that I use the rear brakes more
> than the front. Most of the wear occur during wet conditions. Any
> opinions? (A possible control would be if someone are riding their
> bikes with clean rims all the time..).
Jobst Brandt replied:
Assuming you are using the same pads front and rear, it seems
reasonable
that your rear brake should wear faster because it is the one that
usually
gets the most use in bad traction and bad traction with wet grit eats
rims.
In dry conditions, rims hardly wear and in dry conditions you can
break
hard with the front brake. This heavier use of the front brake in the
dry
does not make up for the wear in a few gritty wet miles.
jobst_bra...@hplabs.hp.com
*******
Tosspot
> How many miles should a rim last with rim brakes? I'm talking about an
> ali rim, used in wet but clean conditions, no salt, Magura hydraulic
> rim brakes with standard black pads. I need to know if I should keep
> on on standby. My annual distance is about 2600km/1600m.
'Pends, hilly terrain will kill them quicker, but ime, 10,000+ miles
all weather commuting on Rigida Zax 19s (or whatever they call them
this year) and V's.
I can't see the hydraulics affecting it much because I would have
thought the pressure on the rims is more a function of how fast you
want to stop.
Marcin J.
Don't know. For sure it is not due to heavy panniers since all my luggagee
is carried in a rucksack and I don't overuse rear brake. On my other mtb
with disc brakes both sets of pads wear out at the same rate. I think I vote
for Jobst explanation linked by Dan O. Also the argument that more loaded
(rear in this case) wheel sinks deeper in mud/ wet soil is in accordance
with my observations. The bike can be best described as a mudguarded rigid
aggressive mtb commuter.
Here are some pics
http://picasaweb.google.pl/xc0rider/BeautifulFracture#
This is the second rim in that bike (Fir Polar). The first one (Gipiemme
Techno M416) has broken in the more usual fashion - one flange just snapped
away but the "intersection" remained intact. None of them was a catastrophic
failure. I've ridden more than 20 km with the latest fracture. Perhaps the
fact that it is 16 spoke wheel has something to do with the fracture or very
small indent at the edge of the broken flange but natural wear-off remains
the most imortant factor IMO.
--
Cheers
marcin
thirty-six
> How many miles should a rim last with rim brakes? I'm talking about an
> ali rim, used in wet but clean conditions, no salt, Magura hydraulic
> rim brakes with standard black pads. I need to know if I should keep
> on on standby. My annual distance is about 2600km/1600m.
>
> I'm not a know-all. I don't need to be. I know who to ask.
Aluminium rims are not measured in miles. They are measured according
to wheel diameter (including tyre) in inches or millimetres. A last
for a rim is most unusual, but perhaps feasible for low output
production. What material do you intend to use for the last?
Marcin J.
thirty-six
> Andre Jute wrote:
> > On Nov 1, 12:42 pm, "Marcin J." <xc-ri...@wp.pl> wrote:
> >> Cheap Al rims without special braking surfaces, most of the time
> >> with yellow Corratec pads, all weather, city, smooth/medium terrain:
> >> rear - 5000 km,
> >> front - 10000 km and is still alive.
>
> >> --
> >> Cheers
> >> marcin
>
> > Why does your rear rim wear out first? -- AJ
>
> Don't know. For sure it is not due to heavy panniers since all my luggagee
> is carried in a rucksack and I don't overuse rear brake. On my other mtb
> with disc brakes both sets of pads wear out at the same rate. I think I vote
> for Jobst explanation linked by Dan O. Also the argument that more loaded
> (rear in this case) wheel sinks deeper in mud/ wet soil is in accordance
> with my observations. The bike can be best described as a mudguarded rigid
> aggressive mtb commuter.
>
>
> This is the second rim in that bike (Fir Polar). The first one (Gipiemme
> Techno M416) has broken in the more usual fashion - one flange just snapped
> away but the "intersection" remained intact. None of them was a catastrophic
> failure. I've ridden more than 20 km with the latest fracture. Perhaps the
> fact that it is 16 spoke wheel has something to do with the fracture or very
> small indent at the edge of the broken flange but natural wear-off remains
> the most imortant factor IMO.
>
Peculier that you should ride the fractured rim. I'm thinking that
perhaps the rim was designed to have a specific tape stuck down and
this would have mitigated failure.
AMuzi
Trevor, every time I think you are a human, your idiot robot
software reveals itself again.
--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971
thirty-six
Duh, fibreglass, cabon or metal tape, stuck with a resin of some
tenacious type. Seems entirely appropriate to close those holes for
they serve no purpose except to aid the insertion of the spoke
nipple. What specifically do you object to, or are you just being
purely objectionable.
Andre Jute
> Andre Jute wrote:
> > On Nov 1, 12:42 pm, "Marcin J." <xc-ri...@wp.pl> wrote:
> >> Cheap Al rims without special braking surfaces, most of the time
> >> with yellow Corratec pads, all weather, city, smooth/medium terrain:
> >> rear - 5000 km,
> >> front - 10000 km and is still alive.
>
> >> --
> >> Cheers
> >> marcin
>
> > Why does your rear rim wear out first? -- AJ
>
> Don't know. For sure it is not due to heavy panniers since all my luggagee
> is carried in a rucksack and I don't overuse rear brake. On my other mtb
> with disc brakes both sets of pads wear out at the same rate. I think I vote
> for Jobst explanation linked by Dan O. Also the argument that more loaded
> (rear in this case) wheel sinks deeper in mud/ wet soil is in accordance
> with my observations. The bike can be best described as a mudguarded rigid
> aggressive mtb commuter.
>
>
> This is the second rim in that bike (Fir Polar). The first one (Gipiemme
> Techno M416) has broken in the more usual fashion - one flange just snapped
> away but the "intersection" remained intact. None of them was a catastrophic
> failure. I've ridden more than 20 km with the latest fracture. Perhaps the
> fact that it is 16 spoke wheel has something to do with the fracture or very
> small indent at the edge of the broken flange but natural wear-off remains
> the most imortant factor IMO.
>
> --
> Cheers
> marcin
Okay. We have two explanations, one of deliberately greater use of the
rear brake in particular circumstance from Sorni, one of naturally
greater wear on rear wheels in the wet because of greater load from
Jobst. Seems a pretty comprehensive answer to me.
The practical upshot is that I will start not using the rear brake
routinely in situations where it isn't really required to control the
bike.
Slainte!
Andre Jute
The rest is magic hidden in the hub.
For rare hub gear bikes, visit Jute on Bicycles at
http://www.audio-talk.co.uk/fiultra/BICYCLE%20%26%20CYCLING.html
Norman
wrote:
> "Marcin J." <xc-ri...@wp.pl> considered Mon, 2 Nov 2009 20:37:16 +0100
> and dirty water over the rear wheel has more than a little to do with
> it.
> The front rim stays relatively clean, so doesn't get abraded as much.
> The degree does vary with the conditions you ride in, but I can't
> think of any conditions where the rear stays cleaner than the front.
The front also kicks most of its grit & such back against
the down tube, or forward into the open air (& back into
my face, bleh), where the rear, what doesn't fly freely back
goes against the seat-tube, preserving it for future rotations.
Unless you have fenders, in which case it's nearly the same.
datakoll
What has.... ?
72 on rim life.
left out off course is soil composition, percentage of clay, silica,
and moist importante, silica type for there are rounded silica;s and
very sharp nasty silica's blended with a light admixture of real
sticky clays.
In our country, one may inquire of the county agent or state ag
university of what soil types are found in your area
or if actually interested, collect samples, examine with mag glass or
microscope if nabberly available.
soil type is prob the moist important variable here beyond sloth.
as for those wet downhills moist likely forced on the rider,
sandstones wih silica or granites, dacites compoundavailable
abrasives
how that for BS ?
Tom Sherman °_°
> [...]
> I almost never use a rear brake. My fixer doesn't even have one. The
> rear brake is only of any use in really slippery conditions or long
> braking descents.
My trike lacks a rear brake, not that it would be of much use other than
skidding the wheel.
--
Tom Sherman - 42.435731,-83.985007
I am a vehicular cyclist.
Tom Sherman °_°
> AMAZIN'
>
> What has.... ?
>
> 72 on rim life.
>
> left out off course is soil composition, percentage of clay, silica,
> and moist importante, silica type for there are rounded silica;s and
> very sharp nasty silica's blended with a light admixture of real
> sticky clays.
>
> In our country, one may inquire of the county agent or state ag
> university of what soil types are found in your area
>
> or if actually interested, collect samples, examine with mag glass or
> microscope if nabberly available.
>
You also need a hand auger, Munsell color charts and the skill to do
textural classification by feel, unless equipped to do particle size
distribution analysis.
> soil type is prob the moist important variable here beyond sloth.
>
Eh: <http://www.hedweb.com/animimag/sloths.jpg>? They are arboreal.
> as for those wet downhills moist likely forced on the rider,
> sandstones wih silica or granites, dacites compoundavailable
> abrasives
>
> how that for BS ?
Does he have you kill-filed?
datakoll
aw Tom don't discourage the already inflicted. Yawl can see sharp sand
particles. One good test is dropping a few on a microcloth then
rubbing same over ur camera lens/
Am I killlfilled ? Read 'Spy Who CIFTC' ?
Chalo
>
> I almost never use a rear brake. My fixer doesn't even have one. The
> rear brake is only of any use in really slippery conditions or long
> braking descents.
I used to ride that way too, almost never touching the rear brake.
After a number of bent forks, buckled frames, and surprise front wheel
skids, I have arrived at the conclusion that it's generally better to
distribute the braking load over both wheels.
Chalo
thirty-six
wrote:
> Peter Cole wrote:
> > [...]
> > I almost never use a rear brake. My fixer doesn't even have one. The
> > rear brake is only of any use in really slippery conditions or long
> > braking descents.
>
> My trike lacks a rear brake, not that it would be of much use other than
> skidding the wheel.
To initiate a sliding turn, or do you use gloves for that?
thirty-six
Slamming on the rear on soft ground can work better than trying to be
delicate with the brakes as the rear tyre digs down and improves
braking by using the sides of the tyre. This even helps with
relatively smooth tyres but a protective rubber skin on the sidewall
is indeed helpful if you want your tyre to last. It is probably the
best way to stop a bicycle on deep gravel.