Disc brakes squeal due to loose pads?

[Michael Press]

I have Avid Ball Bearing Road disc brakes on my commuting (road) bike.
The pads have a little play in them - they'll rock about 1mm if you
push forward and back (along the axis of the bike, not in toward the
rotor) on the little pad mounting stems. (Avid tech support sent me
new pad mounting clips but it only reduced the pad movement slightly.)

Here's the problem - the front brakes squeal when the applied at any
pressure less than death-grip. Rear brake is fine. The brakes work
great, but the squealing is loud and VERY annoying.

Are the pads supposed to move that much? Is that likely the cause of
the squealing, or is this just the kind of disc brake squealing I've
read about on this NG? I recall suggestions about using mud on the
rotors to reduce squeal - any suggestions for that?

Thanks,
Michael

[SDMike]

"Michael Press" > wrote in message
...
> I have Avid Ball Bearing Road disc brakes on my commuting (road) bike.
> The pads have a little play in them - they'll rock about 1mm if you
> push forward and back (along the axis of the bike, not in toward the
> rotor) on the little pad mounting stems. (Avid tech support sent me
> new pad mounting clips but it only reduced the pad movement slightly.)
>
> Here's the problem - the front brakes squeal when the applied at any
> pressure less than death-grip. Rear brake is fine. The brakes work
> great, but the squealing is loud and VERY annoying.
>
> Are the pads supposed to move that much? Is that likely the cause of
> the squealing, or is this just the kind of disc brake squealing I've
> read about on this NG? I recall suggestions about using mud on the
> rotors to reduce squeal - any suggestions for that?
>
> Thanks,
> Michael

Have you tried cleaning off the rotors with Dawn and water? Sometimes when you
get oily fingerprints/etc. on the rotors is screws everything up.

If the Dawn + H2O don't work, then try some really fine mud. It may scrape off
both contaminated layers.

If you haven't done it, reverse the QR on the wheels so you're not tempted to
grab the rotor when you're installing the wheel in the dropout.

HTH,

M

[Werehatrack]

On Tue, 15 Jun 2004 09:57:43 -0400, Michael Press
> may have said:

>I have Avid Ball Bearing Road disc brakes on my commuting (road) bike.
>The pads have a little play in them - they'll rock about 1mm if you
>push forward and back (along the axis of the bike, not in toward the
>rotor) on the little pad mounting stems. (Avid tech support sent me
>new pad mounting clips but it only reduced the pad movement slightly.)
>
>Here's the problem - the front brakes squeal when the applied at any
>pressure less than death-grip. Rear brake is fine. The brakes work
>great, but the squealing is loud and VERY annoying.
>
>Are the pads supposed to move that much?

Yes.

>Is that likely the cause of
>the squealing,

No.

>or is this just the kind of disc brake squealing I've
>read about on this NG?

Disc brake squeal is caused by a high-frequency cyclic oscillation in
the pad/caliper and pad/disc interfaces; stabilize the former, and the
squeal will generally go away. If there is enough clearance for the
pad to move at all, there's enough motion possible to permit squeal.
Since the pad must be able to float a bit in nearly all caliper
designs, squeal is possible in virtually all disc brake systems.

>I recall suggestions about using mud on the
>rotors to reduce squeal - any suggestions for that?

Counterproductive even when effective.

I suggest going to an auto parts store and getting some disc brake
anti-squeal compound; apply it to the back of the pads, NOT the
friction surface. Follow the instructions included with the product.
Be aware that it's sticky, and most types must dry thoroughly before
the pads can be reinstalled. Just about any of these compounds will
usually damp the oscillations and silence the squeal. Short-term
reduction in squeal can sometimes be had by applying a very thin film
of high-temp grease to the back of the pad, but this is an inherently
hazardous method as it is possible for the grease to contaminate the
friction material too easily. I have also seen other anti-squeal
measures used, but I disdain the majority of them due to the fact that
a reasonably reliable and generally inexpensive solution is available
which is likely to be more effective.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

[jim beam]

both my avids & shimanos squealed bad until i discovered e.b.c. pads.
i've used them ever since and have had no problems whatsoever in all
kinds of conditions.

Michael Press wrote:

> I have Avid Ball Bearing Road disc brakes on my commuting (road) bike.
> The pads have a little play in them - they'll rock about 1mm if you
> push forward and back (along the axis of the bike, not in toward the
> rotor) on the little pad mounting stems. (Avid tech support sent me
> new pad mounting clips but it only reduced the pad movement slightly.)
>
> Here's the problem - the front brakes squeal when the applied at any
> pressure less than death-grip. Rear brake is fine. The brakes work
> great, but the squealing is loud and VERY annoying.
>
> Are the pads supposed to move that much? Is that likely the cause of
> the squealing, or is this just the kind of disc brake squealing I've
> read about on this NG? I recall suggestions about using mud on the
> rotors to reduce squeal - any suggestions for that?
>
> Thanks,
> Michael

[Michael Press]

jim beam > wrote:
>both my avids & shimanos squealed bad until i discovered e.b.c. pads.
>i've used them ever since and have had no problems whatsoever in all
>kinds of conditions.

Green or gold?

Thanks,
Michael

[Michael Press]

Werehatrack > wrote:
>On Tue, 15 Jun 2004 09:57:43 -0400, Michael Press
> may have said:

>I suggest going to an auto parts store and getting some disc brake
>anti-squeal compound; apply it to the back of the pads, NOT the
>friction surface. Follow the instructions included with the product.

Wow, sounds perfect. I need some more loctite anyway, so i'll look
for the stuff at the auto parts store.

Thanks,
Michael

[jim beam]

green

Michael Press wrote:

> jim beam > wrote:
>
>>both my avids & shimanos squealed bad until i discovered e.b.c. pads.
>>i've used them ever since and have had no problems whatsoever in all
>>kinds of conditions.
>
>
> Green or gold?
>
> Thanks,
> Michael

[Michael Press]

"SDMike" > wrote:

>
>Have you tried cleaning off the rotors with Dawn and water? Sometimes when you
>get oily fingerprints/etc. on the rotors is screws everything up.
>

Tried it last night. It stopped the squealing for the first 7 miles,
but then it returned... :-(

Michael

[John]

"jim beam" > wrote in message
m...
> both my avids & shimanos squealed bad until i discovered e.b.c. pads.
> i've used them ever since and have had no problems whatsoever in all
> kinds of conditions.
>
> Michael Press wrote:
>
> > I have Avid Ball Bearing Road disc brakes on my commuting (road) bike.
> > The pads have a little play in them - they'll rock about 1mm if you
> > push forward and back (along the axis of the bike, not in toward the
> > rotor) on the little pad mounting stems. (Avid tech support sent me
> > new pad mounting clips but it only reduced the pad movement slightly.)
> >
> > Here's the problem - the front brakes squeal when the applied at any
> > pressure less than death-grip. Rear brake is fine. The brakes work
> > great, but the squealing is loud and VERY annoying.
> >
> > Are the pads supposed to move that much? Is that likely the cause of
> > the squealing, or is this just the kind of disc brake squealing I've
> > read about on this NG? I recall suggestions about using mud on the
> > rotors to reduce squeal - any suggestions for that?
> >
> > Thanks,
> > Michael

I'd love to get the EBC pads. Who might be a good source for them in the
U.S.?

Thanks,
John




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[jim beam]

John wrote:
> "jim beam" > wrote in message
> m...
>
>>both my avids & shimanos squealed bad until i discovered e.b.c. pads.
>>i've used them ever since and have had no problems whatsoever in all
>>kinds of conditions.
>>
>>Michael Press wrote:
>>
>>
>>>I have Avid Ball Bearing Road disc brakes on my commuting (road) bike.
>>>The pads have a little play in them - they'll rock about 1mm if you
>>>push forward and back (along the axis of the bike, not in toward the
>>>rotor) on the little pad mounting stems. (Avid tech support sent me
>>>new pad mounting clips but it only reduced the pad movement slightly.)
>>>
>>>Here's the problem - the front brakes squeal when the applied at any
>>>pressure less than death-grip. Rear brake is fine. The brakes work
>>>great, but the squealing is loud and VERY annoying.
>>>
>>>Are the pads supposed to move that much? Is that likely the cause of
>>>the squealing, or is this just the kind of disc brake squealing I've
>>>read about on this NG? I recall suggestions about using mud on the
>>>rotors to reduce squeal - any suggestions for that?
>>>
>>>Thanks,
>>>Michael
>
>
> I'd love to get the EBC pads. Who might be a good source for them in the
> U.S.?
>
> Thanks,
> John

your lbs should be able to get them for you. or online at places like
cambria bike.

>
>
>
>
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[Michael Press]

(Evan Evans) wrote:
>I won't say that someday disc brake will become useful , but they
>arn't there yet & i won't use them until they are better than v's.

I've never used V-brakes, but discs are far far superior to road rim
brakes, especially in the wet.

Michael

[SDMike]

"Evan Evans" > wrote in message
om...
> I won't say that someday disc brake will become useful , but they
> arn't there yet & i won't use them until they are better than v's.

"Better" depends on how you define it.

In the muck and slop, discs are FAR superior. In general JRA it isn't as big a
difference.

M

[David Damerell]

Michael Press > wrote:
(Evan Evans) wrote:
>>I won't say that someday disc brake will become useful , but they
>>arn't there yet & i won't use them until they are better than v's.
>I've never used V-brakes, but discs are far far superior to road rim
>brakes, especially in the wet.

I can lift or lock the rear wheel with my rim brakes, wet or dry. How
_exactly_ would discs be superior?
--
David Damerell > flcl?

[Chris B.]

On 17 Jun 2004 18:51:46 +0100 (BST), David Damerell
> wrote:

>Michael Press > wrote:
(Evan Evans) wrote:
>>>I won't say that someday disc brake will become useful , but they
>>>arn't there yet & i won't use them until they are better than v's.

>>I've never used V-brakes, but discs are far far superior to road rim
>>brakes, especially in the wet.
>
>I can lift or lock the rear wheel with my rim brakes, wet or dry. How
>_exactly_ would discs be superior?

Dude! Just look at them!

[Michael Press]

David Damerell > wrote:
>I can lift or lock the rear wheel with my rim brakes, wet or dry. How
>_exactly_ would discs be superior?

I can't. When it gets really wet my stopping distances increase
dramatically. I get almost no braking at first, until the pads
squeegee off the water on the rim.

I weigh 210# and ride in urban traffic, so I prefer the shortest
possible stopping distance when I'm approaching a traffic light at the
bottom of a hill at 30mph in heavy rain with a truck coming through
the intersection.

Michael

[SDMike]

"David Damerell" > wrote in message
...
> Michael Press > wrote:
> (Evan Evans) wrote:
> >>I won't say that someday disc brake will become useful , but they
> >>arn't there yet & i won't use them until they are better than v's.
> >I've never used V-brakes, but discs are far far superior to road rim
> >brakes, especially in the wet.
>
> I can lift or lock the rear wheel with my rim brakes, wet or dry. How
> _exactly_ would discs be superior?
> --
> David Damerell > flcl?

By your argument, why did you leave cantis? Or Rollercams, or Scott
Self-Energizing brakes, or... I could endo with my cantis, skid the rear wheel
with U-brakes. They don't do anything that V-brakes do.

How much stronger braking do you need when you can skid the tires with cantis?

Discs aren't really superior to cantis, Vs, or even Rollercams in the respect
that all can lift the rear wheel, or skid it if you want to.

Where discs shine is when the rims get wet, dirty, and/or worn. Discs have none
of the speeding up feeling that brakes do when a rim's wet. They don't grind
down the sides of your rims when you've been running thru the mud.

And best of all, they're easily replaceable vs. rebuilding a wheel.

Now, discs aren't for everyone. If you ride on bridle trails and MUTs, ferget
it. Don't need 'em. Come riding in the woods of the middle Atlantic (or the
UK) when conditions aren't perfect, then they're not a bad thing.

M

[(Pete Cresswell)]

RE/
> How
>_exactly_ would discs be superior?

- Going down a grade that's slippery and/or covered with loose stones you'd be
able to walk a finer line between washing out the front wheel and not having
enough braking power.

--
PeteCresswell

[SteveDel]

x wrote:
> RE/
> > How _exactly_ would discs be superior?
> - Going down a grade that's slippery and/or covered with loose stones
> you'd be able to walk a finer line between washing out the front wheel
> and not having enough braking power.
> --
> PeteCresswell



And not saying anything about how they are'nt bothered when you suddenly
get a warped rim.

cheers from OZ

Stevedel



--

[David Damerell]

Michael Press > wrote:
>David Damerell > wrote:
>>I can lift or lock the rear wheel with my rim brakes, wet or dry. How
>>_exactly_ would discs be superior?
>I can't. When it gets really wet my stopping distances increase
>dramatically. I get almost no braking at first, until the pads
>squeegee off the water on the rim.

Then you need correctly designed and adjusted rim brakes. Obviously a bad
brake of any design is inadequate.

Our man Cholina weighs a great deal more than you and can get the effects
I describe with rim brakes.
--
David Damerell > Kill the tomato!

[David Damerell]

SDMike > wrote:
>"David Damerell" > wrote in message
>>Michael Press > wrote:
(Evan Evans) wrote:
>>>>I won't say that someday disc brake will become useful , but they
>>>>arn't there yet & i won't use them until they are better than v's.
>>>I've never used V-brakes, but discs are far far superior to road rim
>>>brakes, especially in the wet.
>>I can lift or lock the rear wheel with my rim brakes, wet or dry. How
>>_exactly_ would discs be superior?
>By your argument, why did you leave cantis? Or Rollercams, or Scott
>Self-Energizing brakes,

Actually, I have a conventional cantilever on the front and a Suntour SE
cantilever on the rear; so by my argument, I didn't leave cantilevers
because they do the job well.

If people prefer the relatively easy adjustment of Vs to the relatively
long pad live of cantilevers, that's fair enough...

>Now, discs aren't for everyone. If you ride on bridle trails and MUTs, ferget
>it. Don't need 'em. Come riding in the woods of the middle Atlantic (or the
>UK) when conditions aren't perfect, then they're not a bad thing.

Perhaps you missed the words "road rim brakes" above.
--
David Damerell > Kill the tomato!

[David Damerell]

(Pete Cresswell) > wrote:
>RE/
>>How _exactly_ would discs be superior?
>- Going down a grade that's slippery and/or covered with loose stones you'd be
>able to walk a finer line between washing out the front wheel and not having
>enough braking power.

This does not sound like a typical situation for _road_ rim brakes - not
that I have any difficulty modulating my front brake.
--
David Damerell > Kill the tomato!

[jim beam]

evan & david & the other doubters - you are entitled to your opinion,
but /please/ don't dismiss the experience of others without cause. rim
brakes are fine for the majority of users and in moderate conditions,
but /never/ try telling someone that's had to change rim brake pads half
way through a muddy ride that rim brakes are superior to disk.

it's disks that allow you to ride for three hours caked head to toe in
mud and filth and never miss a beat. rim brakes, when the mud is truly
smeared all over the rim acting like a lubricant, just don't work, even
with a death-grip. disks, being up out of the goop & with their drilled
surfaces, just don't have this problem, hence they are superior for
extreme conditions.

and that's why people in this thread are taking a contrary position to
you - they are relating their experiences.

thanks.

Evan Evans wrote:
> "SDMike" > wrote in message news:<WGjAc.5094$tC5.321@fed1read02>...
>
>>"Evan Evans" > wrote in message
om...
>>
>>>I won't say that someday disc brake will become useful , but they
>>>arn't there yet & i won't use them until they are better than v's.
>>
>>"Better" depends on how you define it.
>>
>>In the muck and slop, discs are FAR superior. In general JRA it isn't as big a
>>difference.
>>
>>M
>
> In the old days i.e. 20 years ago all brakes were lacking power in wet
> conditions. Campy even in the dry :)
> Now days dual pivot solved that for the road. Vs solved that for off
> road. I have never ever had any problem stoping or even locking up a V
> brake in any condition. So how can a disc be any better? Disc are
> nothing but a fancy gadgit. They are in the same vain as those
> spinning hub caps you see on hip hop suv's. Cool factor. As far as Vs
> working with a bent rim. If you bend a rim that bad the frame will
> prevent you from riding. Discs have so many negatives & no real
> positives.

[David Damerell]

jim beam > wrote:
>evan & david & the other doubters - you are entitled to your opinion,
>but /please/ don't dismiss the experience of others without cause. rim
>brakes are fine for the majority of users and in moderate conditions,
>but /never/ try telling someone that's had to change rim brake pads half
>way through a muddy ride that rim brakes are superior to disk.

Evidently you missed the word "road" too. Check with your other sock
puppets to see if they saw it, "tux lover" ?
--
David Damerell > Kill the tomato!

[dvt]

Jim Connelley wrote:
> "SDMike" > wrote in message news:<WGjAc.5094$tC5.321@fed1read02>...
>>In the muck and slop, discs are FAR superior. In general JRA it isn't as big a
>>difference.

> Downhill ... Ever blow a tire off a hot rim?

Nope. Have you?

--
Dave
dvt at psu dot edu

[SDMike]

<snip>
>
> Evidently you missed the word "road" too. Check with your other sock
> puppets to see if they saw it, "tux lover" ?
> --
> David Damerell > Kill the tomato!

That's great, but there's people out there saying categorically "disc brakes are
crap." In more extreme conditions, discs are probably the best choice for
braking. All most other places and for more moderate riding, y'all are right:
discs are overkill.

If I lived somewhere where it rained LOTS and I HAD to ride in it, I'd have
discs on my road bike too. There's nothing like being able to stop without
having to squeegee the water off the rim.

I live in San Diego, so I'm happy with the performance of my road calipers. In
fact, I was tickled pink with the performance of my Dia Compe BRS200s (single
pivot) for many years. The only reason I'm not still riding them is that they
went to my little brother in VA. Who is still riding them!

I can still remember almost flipping myself over the bars shortly after DP
brakes came out and I upgraded one of my bikes. I was used to grabbing a
fistful of brakes. The DPs allowed you to grab fingerfuls of brake and do the
same thing.

M

[[email protected]]

On 18 Jun 2004 17:19:14 +0100 (BST), David Damerell
> wrote:

>jim beam > wrote:
>>evan & david & the other doubters - you are entitled to your opinion,
>>but /please/ don't dismiss the experience of others without cause. rim
>>brakes are fine for the majority of users and in moderate conditions,
>>but /never/ try telling someone that's had to change rim brake pads half
>>way through a muddy ride that rim brakes are superior to disk.
>
>Evidently you missed the word "road" too. Check with your other sock
>puppets to see if they saw it, "tux lover" ?

Dear David,

Perhaps you ought to say "paved road" or throw a tantrum?

Carl Fogel

[David Damerell]

SDMike > wrote:
>DAvid Damerell:
>>Evidently you missed the word "road" too. Check with your other sock
>>puppets to see if they saw it, "tux lover" ?
>That's great, but there's people out there saying categorically "disc
>brakes are crap."

I am not responsible for all the people "out there", thank God. :-)
--
David Damerell > Kill the tomato!

[(Pete Cresswell)]

RE/
>>- Going down a grade that's slippery and/or covered with loose stones you'd be
>>able to walk a finer line between washing out the front wheel and not having
>>enough braking power.
>
>This does not sound like a typical situation for _road_ rim brakes - not
>that I have any difficulty modulating my front brake.

The only reasons for putting disk brakes on a road bike that I can think of are

- Reliability in the rain
- Being immune to a taco-d wheel
- Not exposing the sidewall to failure after a crash bends a pad enough so it's
bearing on same and the rider is too dumb to have checked before riding on
(don't ask where I got that one....)
- Interchangability with other bikes...

But these are all stretches IMHO.... Frankly, I think I'd even be just as happy
with a v-brake on the rear wheel of my FS if it weren't for my non-standard
calves banging on the control cable...
--
PeteCresswell

[jim beam]

David Damerell wrote:
> jim beam > wrote:
>
>>evan & david & the other doubters - you are entitled to your opinion,
>>but /please/ don't dismiss the experience of others without cause. rim
>>brakes are fine for the majority of users and in moderate conditions,
>>but /never/ try telling someone that's had to change rim brake pads half
>>way through a muddy ride that rim brakes are superior to disk.
>
>
> Evidently you missed the word "road" too. Check with your other sock
> puppets to see if they saw it, "tux lover" ?

what has "road" got to do with it? you're making blanket condemnations
of disk brakes and i'm merely pointing out that my experience with them
has been extremely positive. exactly why this should trigger a hostile
response from you is something i have trouble understanding.

and you, of all people, should be able to figure out the connection
between "tux lover" and my choice of o.s.

[SDMike]

<snip>
> what has "road" got to do with it? you're making blanket condemnations
> of disk brakes and i'm merely pointing out that my experience with them
> has been extremely positive. exactly why this should trigger a hostile
> response from you is something i have trouble understanding.


Don't let him get to you. I think he just likes being contrary just to be
contrary.

I'll do the same thing, but I'm not quite as snooty when I do it.

M

[David Damerell]

jim beam > wrote:
>David Damerell wrote:
>>jim beam > wrote:
>>>but /never/ try telling someone that's had to change rim brake pads half
>>>way through a muddy ride that rim brakes are superior to disk.
>>Evidently you missed the word "road" too. Check with your other sock
>>puppets to see if they saw it, "tux lover" ?
>what has "road" got to do with it?

On the road one will not have to change rim brake pads halfway through a
muddy ride.

>you're making blanket condemnations of disk brakes

This is not true for two reasons; firstly, I am discussing road use, in
response to another poster's use of "road rim brakes" (so not "blanket");
and secondly, I am merely pointing out that they offer no advantages (so
not "condemnations").

>exactly why this should trigger a hostile
>response from you is something i have trouble understanding.

I've not time for sock puppetteers, especially ones like you who have
obviously changed identity merely because the old identity was correctly
identified as a nutcase.
--
David Damerell > Kill the tomato!

[SDMike]

> On the road one will not have to change rim brake pads halfway through a
> muddy ride.
>
David Damerell > Kill the tomato!

And you're sure of this? I know that if you ride a pair of ceramic rims with
normal pads, sometimes you do have to change pads after one ride. Ditto with
carbon wheels. I have firsthand experience with this one.

Conceivably, if you do go ride a muddy road on a road bike, you COULD have the
situation where you'd need to change brake pads pretty quickly.

Not that a road bike would do real well on a mud-fest ride, but that's another
story. A cross bike maybe, but not a road bike with slicks.

M

[[email protected]]

On 21 Jun 2004 15:11:35 +0100 (BST), David Damerell
> wrote:

>jim beam > wrote:
>>David Damerell wrote:
>>>jim beam > wrote:
>>>>but /never/ try telling someone that's had to change rim brake pads half
>>>>way through a muddy ride that rim brakes are superior to disk.
>>>Evidently you missed the word "road" too. Check with your other sock
>>>puppets to see if they saw it, "tux lover" ?
>>what has "road" got to do with it?
>
>On the road one will not have to change rim brake pads halfway through a
>muddy ride.
>
>>you're making blanket condemnations of disk brakes
>
>This is not true for two reasons; firstly, I am discussing road use, in
>response to another poster's use of "road rim brakes" (so not "blanket");
>and secondly, I am merely pointing out that they offer no advantages (so
>not "condemnations").
>
>>exactly why this should trigger a hostile
>>response from you is something i have trouble understanding.
>
>I've not time for sock puppetteers, especially ones like you who have
>obviously changed identity merely because the old identity was correctly
>identified as a nutcase.

Dear David,

This is not true for two reasons.

So far, you've had time for two replies, the second
amusingly claiming that you have no such time.

Even more entertainingly, Jim isn't the one who looks like a
nutcase.

Cheers,

Carl Fogel

[David Damerell]

SDMike > wrote:
David Damerell:
>>On the road one will not have to change rim brake pads halfway through a
>>muddy ride.
>And you're sure of this? I know that if you ride a pair of ceramic rims with
>normal pads, sometimes you do have to change pads after one ride. Ditto with
>carbon wheels. I have firsthand experience with this one.

Insert a "without demented equipment choices" if you like. I get thousands
of miles - in urban conditions, so with relatively frequent braking at
traffic lights, etc.; and I'm not averse to the occasional impromptu
expedition into mud and gravel off-road.

I expect with any basic design of brake you can get a defective model and
setup which chews through pads quickly.
--
David Damerell > Kill the tomato!

[dianne_1234]

On Mon, 21 Jun 2004 09:58:22 -0700, "SDMike" >
wrote:

>Conceivably, if you do go ride a muddy road on a road bike, you COULD have the
>situation where you'd need to change brake pads pretty quickly.
>
>Not that a road bike would do real well on a mud-fest ride, but that's another
>story. A cross bike maybe, but not a road bike with slicks.

Found a report about Eki wearing down his brake pads in 100km. From
http://www.cyclingnews.com/news/?id=2003/mar03/mar13news3

"Ekimov suffered during the two Belgian season openers, particularly
the second one, Kuurne-Brussels-Kuurne, which followed Het Volk."

"The Sunday race was held in cold rain and the road was so slippery
and the tempo so brisk that there was no end to the braking in the
peloton. After 100 km Ekimov found that his brake pads had worn down
right to the metal."

[[email protected]]

Dianne_1234? writes:

>> Conceivably, if you do go ride a muddy road on a road bike, you
>> COULD have the situation where you'd need to change brake pads
>> pretty quickly. Not that a road bike would do real well on a
>> mud-fest ride, but that's another story. A cross bike maybe, but
>> not a road bike with slicks.

> Found a report about Eki wearing down his brake pads in 100km. From
> http://www.cyclingnews.com/news/?id=2003/mar03/mar13news3

> "Ekimov suffered during the two Belgian season openers, particularly
> the second one, Kuurne-Brussels-Kuurne, which followed Het Volk."

> "The Sunday race was held in cold rain and the road was so slippery
> and the tempo so brisk that there was no end to the braking in the
> peloton. After 100 km Ekimov found that his brake pads had worn down
> right to the metal."

There is something wrong here. Either he was using some esoteric
coated rim or flimsy brake pads, because I wore out an MA-2 rim on a
2500mi all rain tour in the alps with brake pad material left on my
Kool-Stop Continental. I have several dozen of these pads that were
worn to the metal in better weather. People ask why I save them while
at the same time claiming that that is impossible. You be the judge.

Jobst Brandt

[jim beam]

wrote:
> Dianne_1234? writes:
>
>
>>>Conceivably, if you do go ride a muddy road on a road bike, you
>>>COULD have the situation where you'd need to change brake pads
>>>pretty quickly. Not that a road bike would do real well on a
>>>mud-fest ride, but that's another story. A cross bike maybe, but
>>>not a road bike with slicks.
>
>
>>Found a report about Eki wearing down his brake pads in 100km. From
>>http://www.cyclingnews.com/news/?id=2003/mar03/mar13news3
>
>
>>"Ekimov suffered during the two Belgian season openers, particularly
>>the second one, Kuurne-Brussels-Kuurne, which followed Het Volk."
>
>
>>"The Sunday race was held in cold rain and the road was so slippery
>>and the tempo so brisk that there was no end to the braking in the
>>peloton. After 100 km Ekimov found that his brake pads had worn down
>>right to the metal."
>
>
> There is something wrong here.

it's definitely extreme, but entirely possible if it's muddy enough.
i've worn out brand new mountian bike brake pads in less than 5 miles of
descent in bad mud. standard rims.

> Either he was using some esoteric
> coated rim or flimsy brake pads, because I wore out an MA-2 rim on a
> 2500mi all rain tour in the alps with brake pad material left on my
> Kool-Stop Continental. I have several dozen of these pads that were
> worn to the metal in better weather. People ask why I save them while
> at the same time claiming that that is impossible. You be the judge.
>
> Jobst Brandt
>

[[email protected]]

Tom Young writes:

>>>> Conceivably, if you do go ride a muddy road on a road bike, you
>>>> COULD have the situation where you'd need to change brake pads
>>>> pretty quickly. Not that a road bike would do real well on a
>>>> mud-fest ride, but that's another story. A cross bike maybe, but
>>>> not a road bike with slicks.

>>> Found a report about Eki wearing down his brake pads in 100km. From
>>> http://www.cyclingnews.com/news/?id=2003/mar03/mar13news3

>>> "Ekimov suffered during the two Belgian season openers, particularly
>>> the second one, Kuurne-Brussels-Kuurne, which followed Het Volk."

>>> "The Sunday race was held in cold rain and the road was so slippery
>>> and the tempo so brisk that there was no end to the braking in the
>>> peloton. After 100 km Ekimov found that his brake pads had worn down
>>> right to the metal."

>> There is something wrong here. Either he was using some esoteric
>> coated rim or flimsy brake pads, because I wore out an MA-2 rim on a
>> 2500mi all rain tour in the alps with brake pad material left on my
>> Kool-Stop Continental. I have several dozen of these pads that were
>> worn to the metal in better weather. People ask why I save them while
>> at the same time claiming that that is impossible. You be the judge.

> Perhaps I came into this thread too late or don't know your history
> when it comes to claims about brake pads, but the last two sentences
> leave me puzzled. Why do you keep brake pads that are worn to the
> metal while claiming that such a thing is impossible?

Perhaps you didn't read what was written. In the rain, descending
Alpine passes I wore out practically new rims with one set of pads. I
have worn out many pads (and rims) but my pads were worn out in dry
weather where rims do not wear significantly while pads do. That
they can be worn to the metal is why I keep them and also to stop
people from educating me on break usage and wear. Some don't even
get the gist when they see the bag of 30 or more worn out Kool-Stop
Continentals.

Jobst Brandt

[[email protected]]

On 21 Jun 2004 20:58:44 -0700, (Tom Young)
wrote:

wrote in message >...
>> Dianne_1234? writes:
>>
>> >> Conceivably, if you do go ride a muddy road on a road bike, you
>> >> COULD have the situation where you'd need to change brake pads
>> >> pretty quickly. Not that a road bike would do real well on a
>> >> mud-fest ride, but that's another story. A cross bike maybe, but
>> >> not a road bike with slicks.
>>
>> > Found a report about Eki wearing down his brake pads in 100km. From
>> > http://www.cyclingnews.com/news/?id=2003/mar03/mar13news3
>>
>> > "Ekimov suffered during the two Belgian season openers, particularly
>> > the second one, Kuurne-Brussels-Kuurne, which followed Het Volk."
>>
>> > "The Sunday race was held in cold rain and the road was so slippery
>> > and the tempo so brisk that there was no end to the braking in the
>> > peloton. After 100 km Ekimov found that his brake pads had worn down
>> > right to the metal."
>>
>> There is something wrong here. Either he was using some esoteric
>> coated rim or flimsy brake pads, because I wore out an MA-2 rim on a
>> 2500mi all rain tour in the alps with brake pad material left on my
>> Kool-Stop Continental. I have several dozen of these pads that were
>> worn to the metal in better weather. People ask why I save them while
>> at the same time claiming that that is impossible. You be the judge.
>>
>> Jobst Brandt
>>
>
>
>Perhaps I came into this thread too late or don't know your history
>when it comes to claims about brake pads, but the last two sentences
>leave me puzzled. Why do you keep brake pads that are worn to the
>metal while claiming that such a thing is impossible?

Dear Tom,

Possibly what Jobst was saying was that people ask him why
he saves worn brake pads while at the same time the same
people (not Jobst) claim that (something about wear and
weather) is impossible.

Since no one was claiming in this thread that brake pads
could not be worn to the metal in better weather than Ekimov
wore his brake pads down to the metal, it's a somewhat
puzzling post.

There may be something intended about brake pad wear versus
rim wear, but I couldn't figure it out, either. Let's hope
for clarification.

Carl Fogel

[Michael Press]

David Damerell > wrote:
>
>>you're making blanket condemnations of disk brakes
>
>This is not true for two reasons; firstly, I am discussing road use, in
>response to another poster's use of "road rim brakes" (so not "blanket");
>and secondly, I am merely pointing out that they offer no advantages (so
>not "condemnations").

Well, that's still a blanket generatlity (condemnation? ;-), just of
disc brakes for road bikes rather than disc brakes in general.

I'm the original poster of disc vs. rim brakes for road bikes, and
disc brakes absolutely provide an advantage over rim brakes. I've got
a road bike with Ultegra double pivot calipers and a road bike with
Avid mechanical disc brakes. I frequently alternate them, in wet and
dry conditions, so I have frequent direct comparisons between
high-quality rim and disc brakes in various weather conditions.

And, as I stated earlier in this post, 1) in dry weather the disc
brakes stop me slightly faster, 2) in light rain conditions the disc
brakes stop me noticeably faster (i.e. the rim brakes start increasing
stopping distance), and 3) in heavy rain conditions the disc brakes
lose no stopping power at all over dry conditions, while the rim
brakes double or triple their stopping distances. The discs also
retain "modulation", meaning good feel for how much brake is being
applied, in all conditions; the rim brakes lose modulation in the
wet, where you pretty much have to mash them to get any stopping
power.

This is my experience. Others may have different experiences, but
unlike other posters, I won't discount their experiences with blanket
generalities.

Michael

[Michael Press]

Werehatrack > wrote:
>On Tue, 15 Jun 2004 09:57:43 -0400, Michael Press
> may have said:
>
>>I have Avid Ball Bearing Road disc brakes on my commuting (road) bike.
<snip>
>>Here's the problem - the front brakes squeal when the applied at any
>>pressure less than death-grip. Rear brake is fine. The brakes work
>>great, but the squealing is loud and VERY annoying.
<snip>
>I suggest going to an auto parts store and getting some disc brake
>anti-squeal compound; apply it to the back of the pads, NOT the
>friction surface. Follow the instructions included with the product.
>Be aware that it's sticky, and most types must dry thoroughly before
>the pads can be reinstalled. Just about any of these compounds will
>usually damp the oscillations and silence the squeal.

Worked perfectly! No squeal at all now. Thanks.

Michael

[David Damerell]

Michael Press > wrote:
>David Damerell > wrote:
>>>you're making blanket condemnations of disk brakes
>>This is not true for two reasons; firstly, I am discussing road use, in
>>response to another poster's use of "road rim brakes" (so not "blanket");
>>and secondly, I am merely pointing out that they offer no advantages (so
>>not "condemnations").
>Well, that's still a blanket generatlity (condemnation? ;-), just of
>disc brakes for road bikes rather than disc brakes in general.

Manifestly it is not a blanket generality when you must first describe the
specifics involved.

>And, as I stated earlier in this post, 1) in dry weather the disc
>brakes stop me slightly faster, 2) in light rain conditions the disc
>brakes stop me noticeably faster (i.e. the rim brakes start increasing
>stopping distance), and 3) in heavy rain conditions the disc brakes
>lose no stopping power at all over dry conditions, while the rim
>brakes double or triple their stopping distances.

Then your rim brakes are incompetently adjusted or designed. A good rim
brake will lift the rear wheel. You cannot have more braking than that.
What part of this escapes you?

>applied, in all conditions; the rim brakes lose modulation in the
>wet, where you pretty much have to mash them to get any stopping
>power.

This sounds more like the days of steel rims than modern equipment.

>This is my experience. Others may have different experiences, but
>unlike other posters, I won't discount their experiences with blanket
>generalities.

Unfortunately the "blanket generality" I am using is elementary applied
mathematics.
--
David Damerell > flcl?

[Michael Press]

David Damerell > wrote:

>>And, as I stated earlier in this post, 1) in dry weather the disc
>>brakes stop me slightly faster, 2) in light rain conditions the disc
>>brakes stop me noticeably faster (i.e. the rim brakes start increasing
>>stopping distance), and 3) in heavy rain conditions the disc brakes
>>lose no stopping power at all over dry conditions, while the rim
>>brakes double or triple their stopping distances.
>
>Then your rim brakes are incompetently adjusted or designed. A good rim
>brake will lift the rear wheel. You cannot have more braking than that.
>What part of this escapes you?

The "wet" part seems to escape you.

>>applied, in all conditions; the rim brakes lose modulation in the
>>wet, where you pretty much have to mash them to get any stopping
>>power.
>
>This sounds more like the days of steel rims than modern equipment.

Again, discounting others' experiences...

>>This is my experience. Others may have different experiences, but
>>unlike other posters, I won't discount their experiences with blanket
>>generalities.
>
>Unfortunately the "blanket generality" I am using is elementary applied
>mathematics.

Uh huh. Oh yeah, NOW I remember learning "disc brakes suck" in math
class.

Just so you know, I won't be responding any more to your posts. It's
not worth my time to argue with someone who just likes to be contrary.

Michael

[David Damerell]

Michael Press > wrote:
>David Damerell > wrote:
>>Michael Press > wrote:
>>Then your rim brakes are incompetently adjusted or designed. A good rim
>>brake will lift the rear wheel. You cannot have more braking than that.
>>What part of this escapes you?
>The "wet" part seems to escape you.

A good rim brake will lift the rear wheel in the wet. You cannot have more
braking than that. What part of this escapes you?

>>>applied, in all conditions; the rim brakes lose modulation in the
>>>wet, where you pretty much have to mash them to get any stopping
>>>power.
>>This sounds more like the days of steel rims than modern equipment.
>Again, discounting others' experiences...

That is not true. I am not disputing that your brakes do not perform well;
I am merely pointing out that, since rim brakes can work perfectly well in
the wet, that is because yours are inferior, not because of an inherent
limitation of the design. Obviously one can equally well obtain an
inferior disc brake; that would not imply that no disc brake works well.

>>>This is my experience. Others may have different experiences, but
>>>unlike other posters, I won't discount their experiences with blanket
>>>generalities.
>>Unfortunately the "blanket generality" I am using is elementary applied
>>mathematics.
>Uh huh. Oh yeah, NOW I remember learning "disc brakes suck" in math
>class.

Evidently you didn't learn anything, or you would be able to see how the
position of the CoG relative to the front contact patch informs maximum
braking.

>Just so you know, I won't be responding any more to your posts.

Of course not; you don't have an argument, merely a set of vague
insinuations. This is an attempt to conceal that fact.
--
David Damerell > flcl?

[jim beam]

David Damerell wrote:

> Michael Press > wrote:
>
>>David Damerell > wrote:
>>
>>>Michael Press > wrote:
>>>Then your rim brakes are incompetently adjusted or designed. A good rim
>>>brake will lift the rear wheel. You cannot have more braking than that.
>>>What part of this escapes you?
>>
>>The "wet" part seems to escape you.
>
>
> A good rim brake will lift the rear wheel in the wet. You cannot have more
> braking than that. What part of this escapes you?
>
>
>>>>applied, in all conditions; the rim brakes lose modulation in the
>>>>wet, where you pretty much have to mash them to get any stopping
>>>>power.
>>>
>>>This sounds more like the days of steel rims than modern equipment.
>>
>>Again, discounting others' experiences...
>
>
> That is not true. I am not disputing that your brakes do not perform well;
> I am merely pointing out that, since rim brakes can work perfectly well in
> the wet, that is because yours are inferior, not because of an inherent
> limitation of the design. Obviously one can equally well obtain an
> inferior disc brake; that would not imply that no disc brake works well.
>
>
>>>>This is my experience. Others may have different experiences, but
>>>>unlike other posters, I won't discount their experiences with blanket
>>>>generalities.
>>>
>>>Unfortunately the "blanket generality" I am using is elementary applied
>>>mathematics.
>>
>>Uh huh. Oh yeah, NOW I remember learning "disc brakes suck" in math
>>class.
>
>
> Evidently you didn't learn anything, or you would be able to see how the
> position of the CoG relative to the front contact patch informs maximum
> braking.

david, you are correct that when the brakes are fully effective, maximum
braking is defined in terms of the above. but it is incorrect to assume
that all brakes are effective to this level in all conditions. foreign
material [mud] between the brake pad & the braking surface has a
substantially negative impact on their friction coefficient and can
easily cause the brake to not be able to approach the above limit.

please also remember that not everyone lives in flat country like you.
in my case, 210lbs [15 stone?] of lard contending with several miles of
gradient 6" deep in winter effluent are not optimum conditions for rim
brakes. next time you're in the san francisco bay area, you're welcome
to borrow my guest bike and see what i mean. you'll enjoy it -
california rain is much warmer than british rain.

>
>
>>Just so you know, I won't be responding any more to your posts.
>
>
> Of course not; you don't have an argument, merely a set of vague
> insinuations. This is an attempt to conceal that fact.

[[email protected]]

David Damerell writes:

> That is not true. I am not disputing that your brakes do not perform
> well; I am merely pointing out that, since rim brakes can work
> perfectly well in the wet, that is because yours are inferior, not
> because of an inherent limitation of the design. Obviously one can
> equally well obtain an inferior disc brake; that would not imply
> that no disc brake works well.

I disagree on your assessment of rim brakes on wet rims. I have
performed tests on wet braking that conclusively show that it doesn't
work the way most riders visualize. I have had the opportunity to
brake in water deep enough to submerge the rim and found that there
was practically no brake effect during the immersion. Subsequently I
rode in snow so there was a snow pack on the inner periphery of the
rim. On braking, this snow melts supplying a continuous flow of water
to the braking surface. Braking came back to typical wet weather
effect as the snow was gone and shortly after that full effectiveness
returned.

This is a good test to perform if you ride in snow. I did it because
I ride in snow on occasion and had the distinct feeling of no brakes
in such circumstances. It's not riding through snow but getting it on
the rim that does the mean trick and exposes water lubrication for
what it is. That's also why chains work well until the rain stops,
and then they squeak. RR trains have skidding problems on wet track.

Braking in rain, rims are not as wet as one might assume judging from
these experiments. The effect is mainly a partially wet and warm rim
which is not what occurs on a disc brake that is rapidly heated above
boiling temperatures in use.

Jobst Brandt

[Michael Press]

Jobst, I'm having some trouble understanding exactly what you're
saying here, so please indulge some (possibly obvious to you)
clarifications. I believe that you're agreeing with my subjective
impressions of rim brakes becoming ineffective in the presence of lots
of water, and are stating that you have done some studies to validate
those theories.

wrote:
>> I am not disputing that your brakes do not perform
>> well; I am merely pointing out that, since rim brakes can work
>> perfectly well in the wet, that is because yours are inferior, not
>> because of an inherent limitation of the design.
>
>I disagree on your assessment of rim brakes on wet rims. I have
>performed tests on wet braking that conclusively show that it doesn't
>work the way most riders visualize.

I have no idea what most riders visualize. I've stated my impression
that wet rims brake ineffectively; is that what your tests
conclusively show? Can you provide more detail on these tests?

> I have had the opportunity to
>brake in water deep enough to submerge the rim and found that there
>was practically no brake effect during the immersion.

By "No brake effect during immersion" you mean that braking was
completely ineffective during immersion?

>Subsequently I rode in snow so there was a snow pack on the inner periphery of the
>rim. On braking, this snow melts supplying a continuous flow of water
>to the braking surface. Braking came back to typical wet weather
>effect as the snow was gone and shortly after that full effectiveness
>returned.

So by "Braking came back to typical wet weather effect" you're stating
that when the melting snow supplied a flow of water on the rim, the
effect was the same as during immersion, that is little or no braking
ability?

Thanks,
Michael

[SDMike]

<snip>
>
> >> There is something wrong here. Either he was using some esoteric
> >> coated rim or flimsy brake pads, because I wore out an MA-2 rim on a
> >> 2500mi all rain tour in the alps with brake pad material left on my
> >> Kool-Stop Continental. I have several dozen of these pads that were
> >> worn to the metal in better weather. People ask why I save them while
> >> at the same time claiming that that is impossible. You be the judge.

<snip>Kool-Stop Continentals.
>
> Jobst Brandt
>

See, there's the difference. You're riding some aftermarket pad while Eki is
probably riding the stock D/A pad. I know that I've had wear issues on my D/A
pads pretty quickly.

As always YMMV,

M

[SDMike]

<snip>
> Just so you know, I won't be responding any more to your posts. It's
> not worth my time to argue with someone who just likes to be contrary.
>
> Michael
>
See! Told ya so!

M

[Tom Sherman]

David Damerell wrote:

> ...
> Then your rim brakes are incompetently adjusted or designed. A good rim
> brake will lift the rear wheel. You cannot have more braking than that....

While the above is true theoretically, in the real world a brake that
provides better control of its modulation will allow the rider to apply
a force closer to the theoretical maximum than a brake with poorer
modulation would. This MIGHT allow for shorter stopping distances on a
bicycle equipped with a front disc brake (all else being equal), even
though both the disc brake and rim brake are strong enough to cause the
rear wheel to lift.

--
Tom Sherman – Quad City Area

[[email protected]]

Michael Press writes:

>> I have had the opportunity to brake in water deep enough to
>> submerge the rim and found that there was practically no brake
>> effect during the immersion.

> By "No brake effect during immersion" you mean that braking was
> completely ineffective during immersion?

Yes, there was practically no brake effect as long as the rim was in
the water although there was a small and unacceptably low retardation
that fits the description of complete brake fade.

>> Subsequently I rode in snow so there was a snow pack on the inner
>> periphery of the rim. On braking, this snow melts supplying a
>> continuous flow of water to the braking surface. Braking came back
>> to typical wet weather effect as the snow was gone and shortly
>> after that full effectiveness returned.

> So by "Braking came back to typical wet weather effect" you're stating
> that when the melting snow supplied a flow of water on the rim, the
> effect was the same as during immersion, that is little or no braking
> ability?

Yes. Try it, you'll like it... as the old saying goes.

Jobst Brandt

[Tim McNamara]

jim beam > writes:

> david, you are correct that when the brakes are fully effective,
> maximum braking is defined in terms of the above. but it is
> incorrect to assume that all brakes are effective to this level in
> all conditions. foreign material [mud] between the brake pad & the
> braking surface has a substantially negative impact on their
> friction coefficient and can easily cause the brake to not be able
> to approach the above limit.

Mud, perhaps, but not just water as in rain on the road.

> please also remember that not everyone lives in flat country like
> you.

Have you ever been to England? It's not exactly Holland-like in its
terrain. San Francisco type hills are not hard to find in England.

> in my case, 210lbs [15 stone?] of lard contending with several miles
> of gradient 6" deep in winter effluent are not optimum conditions
> for rim brakes. next time you're in the san francisco bay area,
> you're welcome to borrow my guest bike and see what i mean. you'll
> enjoy it - california rain is much warmer than british rain.

You should try Minnesota's winter riding conditions... ;-)

[Tim McNamara]

Michael Press > writes:

> Jobst, I'm having some trouble understanding exactly what you're
> saying here, so please indulge some (possibly obvious to you)
> clarifications. I believe that you're agreeing with my subjective
> impressions of rim brakes becoming ineffective in the presence of
> lots of water, and are stating that you have done some studies to
> validate those theories.
>
> wrote:
>
>> I have had the opportunity to brake in water deep enough to
>>submerge the rim and found that there was practically no brake
>>effect during the immersion.
>
> By "No brake effect during immersion" you mean that braking was
> completely ineffective during immersion?

Think of it as a water film between the brake pad and the rim. Riding
through a deep puddle, the water competely coats the rim and is
constantly resupplied. Once you're out of the puddle, the rim dries
off rapidly when the brakes are applied. Riding in the rain, water
gets onto the rim in a random pattern from falling raindrops and
splashing from the road surface, so the film is not as fully coating
the surface of the rim and is not as constantly resupplied, so the
brake pads have the chance of drying off the water and getting more
friction against the rim (I think this is what David D. was referring
to).

>>Subsequently I rode in snow so there was a snow pack on the inner
>>periphery of the rim. On braking, this snow melts supplying a
>>continuous flow of water to the braking surface. Braking came back
>>to typical wet weather effect as the snow was gone and shortly after
>>that full effectiveness returned.
>
> So by "Braking came back to typical wet weather effect" you're
> stating that when the melting snow supplied a flow of water on the
> rim, the effect was the same as during immersion, that is little or
> no braking ability?

Yup, that's how I read it. If it's cold enough, the layer of water on
the rim will freeze and then you've really got no brakes. This is
common here in Minnesota for winter riders as the temperatures are
below the freezing point for about 7 months out of the year. An
outlying town recorded an overnight low of 33 deg F last night... We
haven't had summer yet and may not, at the rate things are going.

In really cold weather I either find something else to do, or I ride a
bike with some kind of hub brake (a coaster brake wheel on my track
bike, in my case). It's way too dangerous to be riding in an urban
area- chock full of oblivious latte-sipping cell-phone-talking SUV
drivers- without any damn brakes. Life's too short to be stupid.

[Mark South]

"Tim McNamara" > wrote in message
...
> jim beam > writes:
>
> > david, you are correct that when the brakes are fully effective,
> > maximum braking is defined in terms of the above. but it is
> > incorrect to assume that all brakes are effective to this level in
> > all conditions. foreign material [mud] between the brake pad & the
> > braking surface has a substantially negative impact on their
> > friction coefficient and can easily cause the brake to not be able
> > to approach the above limit.
>
> Mud, perhaps, but not just water as in rain on the road.

The roads I've ridden have enough grit on them that the rain splashes up an
unpleasantly abrasive-sounding mixture onto the rims.

One good reason for having hard brake pad material is that the grinding sound of
wet braking goes away once the grit washes or scrapes out of the pads.

With soft pads, it embeds permanently and the scraping never seems to go
away....

> > please also remember that not everyone lives in flat country like
> > you.
>
> Have you ever been to England? It's not exactly Holland-like in its
> terrain. San Francisco type hills are not hard to find in England.

I had a laugh over this comment by "jim beam". It's not unusual to find roads
in England with gradients of more than 1 in 7.

> > in my case, 210lbs [15 stone?] of lard contending with several miles
> > of gradient 6" deep in winter effluent are not optimum conditions
> > for rim brakes. next time you're in the san francisco bay area,
> > you're welcome to borrow my guest bike and see what i mean. you'll
> > enjoy it - california rain is much warmer than british rain.
>
> You should try Minnesota's winter riding conditions... ;-)

In fact, rain is always at slightly above freezing temp. The difference is in
the ambient temperatures of the air you experience with it.
--
Mark South: World Citizen, Net Denizen

[jim beam]

Tim McNamara wrote:
> jim beam > writes:
>
>
>>david, you are correct that when the brakes are fully effective,
>>maximum braking is defined in terms of the above. but it is
>>incorrect to assume that all brakes are effective to this level in
>>all conditions. foreign material [mud] between the brake pad & the
>>braking surface has a substantially negative impact on their
>>friction coefficient and can easily cause the brake to not be able
>>to approach the above limit.
>
>
> Mud, perhaps, but not just water as in rain on the road.
>
>
>>please also remember that not everyone lives in flat country like
>>you.
>
>
> Have you ever been to England? It's not exactly Holland-like in its
> terrain. San Francisco type hills are not hard to find in England.

yup! and i've been to cambridge too, which is where dd lives. it is
indeed very holland-like. fewer canals perhaps...

>
>
>>in my case, 210lbs [15 stone?] of lard contending with several miles
>>of gradient 6" deep in winter effluent are not optimum conditions
>>for rim brakes. next time you're in the san francisco bay area,
>>you're welcome to borrow my guest bike and see what i mean. you'll
>>enjoy it - california rain is much warmer than british rain.
>
>
> You should try Minnesota's winter riding conditions... ;-)

[[email protected]]

Mark South writes:

> The roads I've ridden have enough grit on them that the rain
> splashes up an unpleasantly abrasive-sounding mixture onto the rims.

This is how riders discovered their rear brake was dragging with dual
pivot brakes and moved them to climb with the rear brake QR open.
Since the QR was often not closed again before the descent, they had
no rear brake. In response, Campagnolo made a single pivot 4:1 brake
for the rear so this would not recur.

> One good reason for having hard brake pad material is that the
> grinding sound of wet braking goes away once the grit washes or
> scrapes out of the pads.

> With soft pads, it embeds permanently and the scraping never seems
> to go away...

Not so with Kool-Stop salmon red pads. That they do not do this is
one of their main features. They do not pick up gouging grit that
eats rims and degrades braking. If there is road grit in the pad,
pumping the brake a couple of sharp times expels these and allows good
braking. That is how I got to these pads in the first place.

Jobst Brandt

[David Damerell]

jim beam > or "tux lover" or whatever sock puppet he's using
this week wrote:
>that all brakes are effective to this level in all conditions. foreign
>material [mud] between the brake pad & the braking surface has a
>substantially negative impact on their friction coefficient and can
>easily cause the brake to not be able to approach the above limit.

This is not an issue in road riding - grit and muck, sure, but not the
thick mud that makes disc brakes a more sensible choice when riding
offroad.

>please also remember that not everyone lives in flat country like you.

I don't. I have been fairly consistently too lazy to update my Web page
since circa 1997.

>in my case, 210lbs [15 stone?] of lard contending with several miles of
>gradient 6" deep in winter effluent are not optimum conditions for rim
>brakes.

You simply cannot beat someone who rides in the UK in terms of filthy
weather conditions - and while multiple-mile hills are a rare enough
affair, steep ones certainly are not. With full panniers I have quite a
bit more than 210 pounds to stop, let alone the addition of a trailer
(which does not change the CoG much, being well-balanced on its own
wheels, but does increase the work to be done in braking.)
--
David Damerell > flcl?

[David Damerell]

> wrote:
>David Damerell writes:
[That rim brakes work well in the wet]
>I disagree on your assessment of rim brakes on wet rims. I have
>performed tests on wet braking that conclusively show that it doesn't
>work the way most riders visualize. I have had the opportunity to
>brake in water deep enough to submerge the rim and found that there
>was practically no brake effect during the immersion. Subsequently I
>rode in snow so there was a snow pack on the inner periphery of the
>rim.

Hang on; I am perfectly willing to grant that rim brakes do not work well
when the bottom of the rim is underwater, or in heavy snow that coats the
rim; I've done both.

I'm not _too_ worried about that, however, because I can't ride very
quickly in such conditions.

However, what is being said is that rim brakes cannot lift the rear wheel
when simply riding in the rain; and that is manifestly false.
--
David Damerell > flcl?

[David Damerell]

Tom Sherman > wrote:
>David Damerell wrote:
>>Then your rim brakes are incompetently adjusted or designed. A good rim
>>brake will lift the rear wheel. You cannot have more braking than that....
>While the above is true theoretically, in the real world a brake that
>provides better control of its modulation will allow the rider to apply
>a force closer to the theoretical maximum than a brake with poorer
>modulation would.

True, but I know well enough that I can get the rear wheel to unload
momentarily in emergency braking situations - thankfully a rare
occurrence, but they happen.

Now, if you want to say that some V-brakes do not modulate well, I'm not
going to argue with that.
--
David Damerell > flcl?

[Benjamin Lewis]

David Damerell wrote:

> > wrote:
>> David Damerell writes:
> [That rim brakes work well in the wet]
>> I disagree on your assessment of rim brakes on wet rims. I have
>> performed tests on wet braking that conclusively show that it doesn't
>> work the way most riders visualize. I have had the opportunity to
>> brake in water deep enough to submerge the rim and found that there
>> was practically no brake effect during the immersion. Subsequently I
>> rode in snow so there was a snow pack on the inner periphery of the
>> rim.
>
> Hang on; I am perfectly willing to grant that rim brakes do not work well
> when the bottom of the rim is underwater, or in heavy snow that coats the
> rim; I've done both.
>
> I'm not _too_ worried about that, however, because I can't ride very
> quickly in such conditions.
>
> However, what is being said is that rim brakes cannot lift the rear wheel
> when simply riding in the rain; and that is manifestly false.

I can lift my rear wheel in heavy rain too. However, I've still found
there to be an increase in stopping distance; the brakes don't start
grabbing as quickly. It hasn't had a large enough effect to make me want
to rush out and buy disc brakes, but it's quite noticeable.

--
Benjamin Lewis

Base 8 is just like base 10, if you are missing two fingers.
-- Tom Lehrer

[foldedpath]

Benjamin Lewis > wrote in
:

> I can lift my rear wheel in heavy rain too. However, I've still found
> there to be an increase in stopping distance; the brakes don't start
> grabbing as quickly. It hasn't had a large enough effect to make me
> want to rush out and buy disc brakes, but it's quite noticeable.

That's why I'm leaning toward disc brakes on a new town commuter/light
trail bike. It's more about quick response than the degree of stopping
power, when a car or a dog pulls out in front of you. I live in the Pacific
Northwest, and the roads are sloppy and wet for about half the year. I've
never loved the way rim brakes work in the rain, so I thought I'd try disc
brakes with this project.

On the other hand... I remember reading someplace (maybe here?) that the
slower reaction time with wet wheels and rim brakes is a better match for a
wet/slippery road surface. I think the idea was that if you couldn't
instantly lock the wheel, you'd be less likely to skid on a wet road. Or
something like that.

I'm not sure that makes sense, but I'm curious what everyone else here
thinks about it. It seems to me that if you have good modulation and an
experienced rider, it's always an advantage if the brakes are immediately
available, instead of having a delay to wipe water off the rim. But I don't
know (never having used disk brakes). Maybe there is a kind of automatic
safety factor in the balance between reduced tire grip on wet roads, and
delayed response with a wet wheel and rim brakes?

--
Mike Barrs

[Tim McNamara]

"Mark South" > writes:

> "Tim McNamara" > wrote in message
> ...
>> jim beam > writes:
>>
>> > david, you are correct that when the brakes are fully effective,
>> > maximum braking is defined in terms of the above. but it is
>> > incorrect to assume that all brakes are effective to this level
>> > in all conditions. foreign material [mud] between the brake pad
>> > & the braking surface has a substantially negative impact on
>> > their friction coefficient and can easily cause the brake to not
>> > be able to approach the above limit.
>>
>> Mud, perhaps, but not just water as in rain on the road.
>
> The roads I've ridden have enough grit on them that the rain
> splashes up an unpleasantly abrasive-sounding mixture onto the rims.
>
> One good reason for having hard brake pad material is that the
> grinding sound of wet braking goes away once the grit washes or
> scrapes out of the pads.
>
> With soft pads, it embeds permanently and the scraping never seems
> to go away....

I use Mathauser or Koolstop salmon pads, which do not seem to get grit
imbedded in them, for this very reason. Brake pads should be one
smooth chunk of material with no grooves or whatever- all those do is
entrap grit.

>> > please also remember that not everyone lives in flat country like
>> > you.
>>
>> Have you ever been to England? It's not exactly Holland-like in
>> its terrain. San Francisco type hills are not hard to find in
>> England.
>
> I had a laugh over this comment by "jim beam". It's not unusual to
> find roads in England with gradients of more than 1 in 7.

Like 1 in 4... :-o

>> > in my case, 210lbs [15 stone?] of lard contending with several
>> > miles of gradient 6" deep in winter effluent are not optimum
>> > conditions for rim brakes. next time you're in the san francisco
>> > bay area, you're welcome to borrow my guest bike and see what i
>> > mean. you'll enjoy it - california rain is much warmer than
>> > british rain.
>>
>> You should try Minnesota's winter riding conditions... ;-)
>
> In fact, rain is always at slightly above freezing temp. The
> difference is in the ambient temperatures of the air you experience
> with it.

Rain? Minnesota winter? Bwahh-haah-hah! Not much rain falls at 20
below F. ;-) Although the last few winters have been very mild with
very little of this, allowing more winter time riding in
above-freezing temps (and greater likelihood of cold rain). Once the
water bottles freeze up on a ride, I park the bike and wait for warmer
weather. I admit it, I ride 6,500 miles a year but I pretty much am a
fair weather rider. I see no reason to be miserable in the pursuit of
having fun.

[Tim McNamara]

foldedpath > writes:

> Benjamin Lewis > wrote in
> :
>
>> I can lift my rear wheel in heavy rain too. However, I've still found
>> there to be an increase in stopping distance; the brakes don't start
>> grabbing as quickly. It hasn't had a large enough effect to make me
>> want to rush out and buy disc brakes, but it's quite noticeable.
>
> That's why I'm leaning toward disc brakes on a new town commuter/light
> trail bike. It's more about quick response than the degree of stopping
> power, when a car or a dog pulls out in front of you. I live in the Pacific
> Northwest, and the roads are sloppy and wet for about half the year. I've
> never loved the way rim brakes work in the rain, so I thought I'd try disc
> brakes with this project.

Well, not only is the water an issue but anodized sidewalls on rims
also adversely affect wet braking. With bare aluminum braking tracks
on the rims and Koolstop salmon pads, wet weather braking is pretty
good (relatively speaking).

[[email protected]]

Tim McNamara writes:

>> With soft pads, it embeds permanently and the scraping never seems
>> to go away....

> I use Matthauser or Kool-stop salmon pads, which do not seem to get
> grit embedded in them, for this very reason. Brake pads should be
> one smooth chunk of material with no grooves or whatever- all those
> do is entrap grit.

It is not grooves that embed grit in the brake pad. The damaging
effect is that the pad so securely holds a piece of grit that it
becomes a cutting tool without dislodging. If you inspect such a
brake pad, you'll find that the major component is oxidized aluminum
shavings that have created a pocket in the pad. Kool-Stop salmon pads
are not immune to grit entrapment but pumping the brake will dislodge
any particle that gets between pad and aluminum rim.

Jobst Brandt

[David Damerell]

Tim McNamara > wrote:
>Well, not only is the water an issue but anodized sidewalls on rims
>also adversely affect wet braking. With bare aluminum braking tracks
>on the rims and Koolstop salmon pads, wet weather braking is pretty
>good (relatively speaking).

Unfortunately, we ask ourselves what's the best way to wear the
anodisation off so we can brake more readily in the rain... and the answer
is, of course, to ride in the rain. :-(
--
David Damerell > flcl?