disk brake squeal

my xt disks squeal like tortured piglets.

if i change pads, the squeal goes for one ride, and returns about half way through the next.

does anyone have any recommendations regarding pad material/manufacture that might help?

jb

I doubt that there is enough variability in pad material to make a difference and especially
from/for a particular manufacturer. Automobile disk pads squeal also and a elastic material is
available to prevent this. IIRC it is applied wet to the pad/piston interface and shifts the squeal
up into inaudible ranges.

"jim beam" <uce@ftc.gov> wrote in message news:TVcza.45$Sh5.5497102@newssvr15.news.prodigy.com...
> my xt disks squeal like tortured piglets.
>
> if i change pads, the squeal goes for one ride, and returns about half way through the next.
>
> does anyone have any recommendations regarding pad material/manufacture that might help?
>
> jb

jim beam wrote:
> my xt disks squeal like tortured piglets.
>
> if i change pads, the squeal goes for one ride, and returns about half way through the next.
>
> does anyone have any recommendations regarding pad material/manufacture that might help?
>
> jb

You probably have grease on the rotor. I just put mud on the rotor and ride 'em. Fine mud without
stones. Stones get in the holes of the rotor and gouge the pads -- not a show stopper, but there's
no stopping power where the gouges are (until you've worn the pads back to even) . I've tried all
kinds of other things and they don't work for me: alcohol, boiling in water, heating with a torch,
simple green, dish detergent. I just keep a tin can with dirt that I sifted through an old screen
near the bike and add water when I need mud. If I'm on the trail and I can't find mud (we had a
drought here last summer), I get dirt in the palm of my hand and add water from my hydration pak.

My theory is that over time, a stubborn layer of chain lube (very slick and designed to stay put)
and oils from the trail water crossings where people have dunked chains (and around here, RVs and
ORVs have dripped engine oil <sigh>) forms a glaze/film on the rotor and the pads. The mud acts
like a cutting agent to scour this off and I believe it also absorbs some as the pads heat up. Give
it a try .

I also use EBC brake pads -- they handle this better than Hayes pads, but I don't know about
Shimano. I like the green. Red wear too fast and are more prone to squeeling and gold just squeel
from day 1 and don't stop very well. YMMV.

David

david-<< I just put mud on the rotor and ride 'em. Fine mud without stones. << I've tried all kinds
of other things and they don't work for me: alcohol, boiling in water, heating with a torch, simple
green, dish detergent. I just keep a tin can with dirt that I sifted through an old screen near the
bike and add water when I need mud.

yikes.......

Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
(303)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"

>I've tried all kinds of other things and they don't work for me: alcohol, boiling in water, heating
>with a torch, simple green, dish detergent.

Have you tried auto disc brake cleaner? Spray can. Smells BAD. Wear safety glasses!

AJS

"David Kunz" <davidk21770@earthlink.net> wrote in message news:3ECDE80D.50402@earthlink.net...
> jim beam wrote:
> > my xt disks squeal like tortured piglets.
> >
> > if i change pads, the squeal goes for one ride, and returns about half way through the next.
> >
> > does anyone have any recommendations regarding pad material/manufacture that might help?
> >
> > jb
>
> You probably have grease on the rotor. I just put mud on the rotor and ride 'em. Fine mud without
> stones. Stones get in the holes of the rotor and gouge the pads -- not a show stopper, but
> there's no stopping power where the gouges are (until you've worn the pads back to even) . I've
> tried all kinds of other things and they don't work for me: alcohol, boiling in water, heating
> with a torch, simple green, dish detergent. I just keep a tin can with dirt that I sifted through
> an old screen near the bike and add water when I need mud. If I'm on the trail and I can't find
> mud (we had a drought here last summer), I get dirt in the palm of my hand and add water from my
> hydration pak.
>
> My theory is that over time, a stubborn layer of chain lube (very slick and designed to stay put)
> and oils from the trail water crossings where people have dunked chains (and around here, RVs and
> ORVs have dripped engine oil <sigh>) forms a glaze/film on the rotor and the pads. The mud acts
> like a cutting agent to scour this off and I believe it also absorbs some as the pads heat up.
> Give it a try .
>
> I also use EBC brake pads -- they handle this better than Hayes pads, but I don't know about
> Shimano. I like the green. Red wear too fast and are more prone to squeeling and gold just squeel
> from day 1 and don't stop very well. YMMV.
>
> David

I haven't any experience with bicycle brake pads, but I have some experience with motorcyle pads.
The squeal might be caused by vibration between the pad and the rotor, especially if the design of
the caliper has the pad free-floating in the caliper, I am not sure if this is the same for bicycle
pads. Rotor run out can induce noise too.

If cleaning the rotor and pad does not help, then a very thin coating of thick grease applied to the
back of the pad (which is attached to the caliper) might serve as a damper for the vibration. There
was also a product on the market for this at one time. It was in liquid or spray form and it dried
into a layer of soft plastic film. I found that the film tended to create a slightly spongy feel to
the brake lever, but it did stop the squeal for me.

David Kunz <davidk21770@earthlink.net> wrote:

> I just put mud on the rotor and ride 'em. Fine mud without stones. Stones get in the holes of the
> rotor and gouge the pads

There is an exceedingly fine mud available that even contains a bit of soap to help things along.
It's called "rubbing compound" and you can get it at an auto supply.

Note that the traditional way to dress glazed disc brake pads is to wet-sand them carefully on a
flat surface, using a figure-eight motion to help keep them from developing a convex curvature.

Chalo Colina

vecchio51@aol.com (Qui si parla Campagnolo) wrote:

> david-<< I just put mud on the rotor and ride 'em. Fine mud without stones. << I've tried all
> kinds of other things and they don't work for me: alcohol, boiling in water, heating with a torch,
> simple green, dish detergent. I just keep a tin can with dirt that I sifted through an old screen
> near the bike and add water when I need mud.
>
> yikes.......

Makes ya wonder how he might go about truing a wheel, don't it?

Chalo Colina

david wrote:

"I just put mud on the rotor and ride 'em. Fine mud without stones.

I've tried all kinds of other things and they don't work for me: alcohol, boiling in water, heating
with a torch, simple green, dish detergent. I just keep a tin can with dirt that I sifted through an
old screen near the bike and add water when I need mud."

And to think for all these years I thought one of the main reasons for having disc's on an MTB was
to keep the brakes OUT of the mud.

Shows what I know... ;-3)

May you have the wind at your back. And a really low gear for the hills! Chris

Chris'Z Corner "The Website for the Common Bicyclist": http://www.geocities.com/czcorner

In article <8b4b7de4.0305231510.4aad35bb@posting.google.com>, chumpychump@hotmail.com says...
> vecchio51@aol.com (Qui si parla Campagnolo) wrote:
>
> > david-<< I just put mud on the rotor and ride 'em. Fine mud without stones. << I've tried all
> > kinds of other things and they don't work for me: alcohol, boiling in water, heating with a
> > torch, simple green, dish detergent. I just keep a tin can with dirt that I sifted through an
> > old screen near the bike and add water when I need mud.
> >
> > yikes.......
>
> Makes ya wonder how he might go about truing a wheel, don't it?
>
Ride strategically-space stairs?

Rick

vecchio51@aol.com (Qui si parla Campagnolo) wrote in message
news:<20030523232922.14902.00000235@mb-m14.aol.com>...
> chump-<< vecchio51@aol.com (Qui si parla Campagnolo) wrote:
>
> > david-<< I just put mud on the rotor and ride 'em. Fine mud without stones. << I've tried all
> > kinds of other things and they don't work for me: alcohol, boiling in water, heating with a
> > torch, simple green, dish detergent. I just keep a tin can with dirt that I sifted through an
> > old screen near the bike and add water when I need mud.
> >
> > yikes....... >><BR><BR>
>
> ALL I wrote was the 'yikes'....

I left in your attribution (david-<<) because I thought it was clear. I think we're on the same page
WRT this "maintenance" technique.

Chalo Colina

Qui si parla Campagnolo wrote:
> chump-<< vecchio51@aol.com (Qui si parla Campagnolo) wrote:
>
>
>>david-<< I just put mud on the rotor and ride 'em. Fine mud without stones. << I've tried all
>>kinds of other things and they don't work for me: alcohol, boiling in water, heating with a torch,
>>simple green, dish detergent. I just keep a tin can with dirt that I sifted through an old screen
>>near the bike and add water when I need mud.
>>
>>yikes....... >><BR><BR>
>
>
> ALL I wrote was the 'yikes'....
>
> Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
> (303)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"

Hey, it works. It was recommended to me by the head wrench at my LBS who's also a long time
mountain biker.

David

A-J-S wrote:
>>I've tried all kinds of other things and they don't work for me: alcohol, boiling in water,
>>heating with a torch, simple green, dish detergent.
>
>
> Have you tried auto disc brake cleaner? Spray can. Smells BAD. Wear safety glasses!

I have Hayes brakes and they specifically say not to use it (or any other auto brake product). I'm
guessing that they use a glue that it disolves (to adhere the brake material to the metal backing).
Since I use EBC pads, this may be moot, but I hesitate to try it...

Someone also recommended trying Comet -- since it has the fine grit and a heavy duty detergent. I
haven't yet .

I started doing this when I had an American Classic hub that used to dump grease on the rear
rotor at random. After dealing with their customer service, I'll NEVER buy another American
Classic product.

David

>
>
> AJS
>
> "David Kunz" <davidk21770@earthlink.net> wrote in message news:3ECDE80D.50402@earthlink.net...
>
>>jim beam wrote:
>>
>>>my xt disks squeal like tortured piglets.
>>>
>>>if i change pads, the squeal goes for one ride, and returns about half way through the next.
>>>
>>>does anyone have any recommendations regarding pad material/manufacture that might help?
>>>
>>>jb
>>
>>You probably have grease on the rotor. I just put mud on the rotor and ride 'em. Fine mud without
>>stones. Stones get in the holes of the rotor and gouge the pads -- not a show stopper, but
>>there's no stopping power where the gouges are (until you've worn the pads back to even) . I've
>>tried all kinds of other things and they don't work for me: alcohol, boiling in water, heating
>>with a torch, simple green, dish detergent. I just keep a tin can with dirt that I sifted through
>>an old screen near the bike and add water when I need mud. If I'm on the trail and I can't find
>>mud (we had a drought here last summer), I get dirt in the palm of my hand and add water from my
>>hydration pak.
>>
>>My theory is that over time, a stubborn layer of chain lube (very slick and designed to stay put)
>>and oils from the trail water crossings where people have dunked chains (and around here, RVs and
>>ORVs have dripped engine oil <sigh>) forms a glaze/film on the rotor and the pads. The mud acts
>>like a cutting agent to scour this off and I believe it also absorbs some as the pads heat up.
>>Give it a try .
>>
>>I also use EBC brake pads -- they handle this better than Hayes pads, but I don't know about
>>Shimano. I like the green. Red wear too fast and are more prone to squeeling and gold just squeel
>>from day 1 and don't stop very well. YMMV.
>>
>>David
>>
>

Bluto wrote:
> David Kunz <davidk21770@earthlink.net> wrote:
>
>
>>I just put mud on the rotor and ride 'em. Fine mud without stones. Stones get in the holes of the
>>rotor and gouge the pads
>
>
> There is an exceedingly fine mud available that even contains a bit of soap to help things along.
> It's called "rubbing compound" and you can get it at an auto supply.
>
> Note that the traditional way to dress glazed disc brake pads is to wet-sand them carefully on a
> flat surface, using a figure-eight motion to help keep them from developing a convex curvature.

Mud's faster, easier, and more readily available -- especailly on the trail! My rotors have about
18k miles on them, have been regularly treated to mud, and both front and rear are still working
quite well .

David