Thread: Shimano XT squeal

2012 brakes
Never had an issue with them last summer. Now, when they heat up, they start squealing, then vibrating... new metals pads with the cooling fins. They are silent until they get hot.... I'm not even talking crazy long descents. Been riding the new pads for 4 days or so. I cleaned the caliper and pads before installing the new pads. Ideas?

Originally Posted by funkendrenchman

2012 brakes
Never had an issue with them last summer. Now, when they heat up, they start squealing, then vibrating... new metals pads with the cooling fins. They are silent until they get hot.... I'm not even talking crazy long descents. Been riding the new pads for 4 days or so. I cleaned the caliper and pads before installing the new pads. Ideas?

I have the same brakes and they are great. Got tired of replacing pads and tried the metallic. Just too loud. Went back to the composite and have never had a problem. i just carry an extra set in my bag in case I burn through them mid ride and have to change them. Have had this some conversation with four or five others. It's the pads.

Originally Posted by Canada1

I have the same brakes and they are great. Got tired of replacing pads and tried the metallic. Just too loud. Went back to the composite and have never had a problem. i just carry an extra set in my bag in case I burn through them mid ride and have to change them. Have had this some conversation with four or five others. It's the pads.

The pads I used last summer were metallic and I had no issues.

I want to try CL's mountain bike pads. Not sure how well known they are but I have a lot of experience with their race car stuff and it's awesome.

What brand pads?

Originally Posted by goldenboy

What brand pads?

Shimano...same ones I used last summer.

I had the same issue this season with my XT's and metal pads. Old one were loud all of a sudden once a little hot. Replaced my old with new ones, cleaned rotors and pads with rubbing alcohol, all the tricks etc. Still loud. It's been super dusty in CB vs last year and I think that might have something to do with it. Switched to Jagwire's semi-metalic and noise issues went away. Actually like them better than the Shimano metalic. Stopping power is fine, little to no fade on long downs, and I'm about 195lbs.

Originally Posted by funkendrenchman

Shimano...same ones I used last summer.

Weird. I've had big issues with koolstops and jagwires in the past, but never with shimanos. good luck.

We're talking about XT m785 brakes, right?

Are you running the ice tech rt -86 rotors? If not, get some, they're awesome. If you already have them, you may need new ones. I've seen some of the rt -86 rotors get worn ultra thin. Like as thin as anything I've ever seen, and seeing as they've only been easy to find for about a year I think they may wear out quickly in exchange for how well they work new.

M-785's should be quiet with either Shimano metallic or resin pads.

Not sure what pads I have (they are stock) but last fall the brakes were silent. After a dormant winter, they were squealing like crazy the first few rides out. Seems to have gone away now, and I didn't do any maintenance. Pretty weird.

Yep, that doesn't help, sorry.

Edit: non Ice-tech rotors.

Switched to Jagwire's semi-metalic and noise issues went away. Actually like them better than the Shimano metalic. Stopping power is fine, little to no fade on long downs, and I'm about 195lbs.

I had the same problem last year, got metallics and the noise started. Cleaned the pads numerous times, replaced both rotors, horrible noise kept up all season. This spring I put a 15$ pair of Serfas semi metallic pads on the front and now no noise from that end. Stopping power is fine and I am happy. Can't wait till the rear metallics wear out.

Originally Posted by donkeykong

Not sure what pads I have (they are stock) but last fall the brakes were silent. After a dormant winter, they were squealing like crazy the first few rides out. Seems to have gone away now, and I didn't do any maintenance. Pretty weird.

.

One of my juicy's quit working so well after just riding 400kms on the back of my car, did you carry the bike on a car, maybe some road shit got on the brakes ?

cleaned / baked / broke in the pads and power returned

Originally Posted by XXX-er

One of my juicy's quit working so well after just riding 400kms on the back of my car, did you carry the bike on a car, maybe some road shit got on the brakes ?

cleaned / baked / broke in the pads and power returned

Good thought but no, I like to keep my bike inside with the backseats down for transport. I thought an alcohol clean of the rotors would help, but one day the noise was just gone so I never bothered.

Originally Posted by funkendrenchman

2012 brakes
Never had an issue with them last summer. Now, when they heat up, they start squealing, then vibrating... new metals pads with the cooling fins. They are silent until they get hot.... I'm not even talking crazy long descents. Been riding the new pads for 4 days or so. I cleaned the caliper and pads before installing the new pads. Ideas?

Exact same thing just happened to me yesterday! I have had these brakes for appx. 6 weeks. They are quiet when cool but as soon as I have a descent longer than 2 minutes they squeal like crazy. I do have the ICE rotors as well. I am not sure what the move is.

Some of the first 785 brakes produced had a problem with leaking mineral oil through where the banjo fitting on the hose attaches to the caliper. Most of the affected brakes came to light and were resolved last summer, but you guys should inspect there to see if maybe that is your problem with the noise. If it seems like your losing oil in those spots and contaminating your rotors the first thing I'd do would be to put a wrench on those fittings to be sure they're tight. If they are leaking and tight, contact Shimano or your LBS.

Other than that I'm out of ideas. Those things should be quiet.

Originally Posted by Finstah

Some of the first 785 brakes produced had a problem with leaking mineral oil through where the banjo fitting on the hose attaches to the caliper. Most of the affected brakes came to light and were resolved last summer, but you guys should inspect there to see if maybe that is your problem with the noise. If it seems like your losing oil in those spots and contaminating your rotors the first thing I'd do would be to put a wrench on those fittings to be sure they're tight. If they are leaking and tight, contact Shimano or your LBS.

Other than that I'm out of ideas. Those things should be quiet.

I had that issue, but solved it with a little super glue. The difference with that problem is that the oil affects the braking power and the squeal occurs no matter how hot the rotor is. My brakes are silent and powerful, until they heat up.

Brought mine in yesterday and talked to them about my brakes. My rear rotor was completely black from rubbing and heating up. The LBS basically told me I am riding them too hard. I have no idea what that means. They are brakes. I need to use them. I can't afford to keep replacing rotors and am not impressed with these to be honest. I had Hayes on my previous bike. They sucked in terms of stopping power, etc. but the rotors never went black!

Use your front brake.

Get a bigger rotor.

Originally Posted by kidwoo

Use your front brake.

Get a bigger rotor.

My front brake gets used. Thank you for answering my question about rotor size. It does matter huh?

Originally Posted by kidwoo

Use your front brake.

Get a bigger rotor.

Why didn't I think of this? Oh wait, because it wasn't a problem the 50 times I rode them last summer or the first 20 days this year.

I wouldn't be suprised if they came out with a bad batch of pads.

Search function? http://www.tetongravity.com/forums/s...t=#post3675333

Short answer; resin pads or hope rotor. Long answer below.

At least in my case this whole thing started because fox generously offered a crash replacement for my 2007 TALAS-X.

The old fork had an IS mount with an XTR caliper. The new TALAS RLC has post mount. If anyone has had to make this switch you probably already know that you can get a IS to post mount adapter, but will have to step up to a 180mm rotor (from 160mm). This probably would have worked out fine if I had gone with resin pads with this set-up, but with the metal ones all I got was squeel and really grabby braking.

I tried all the solutions above; cleaning, sanding; even tried some disc brake anti-squeel stuff that home depot sells which just made for poor braking for the first half of the first ride and then back to godawful squeeling and grabby braking.

I suspected the problem was vibration related and that the IS-post adapter might be introducing some extra flex in the system so I ditched the adapter and put on an XT post mount caliper and went back to a 160mm rotor (new ICE). Still squeely and grabby.

As a last resort I tried the resin pads and voila, smooth braking and no squeel!

If anyone's interested I've now got an extra hope IS-post mount adapter and a 180mm XT ICE rotor, slightly used. 180mm seemed like overkill for a 5.5" travel all-mountain rig (2007 stumpy FSR), especially since I'm only using a 140mm rear rotor (hope floating sawtooth).

FWIW, I think the hope rotor is less problematic than the shimano ICE stuff, but couldn't find it in center-lock for the front and didn't want to use yet another adapter. I also recently replaced an XTR rear wheel with an Easton Haven so could use the hope 6-bolt on the rear. Still running an XTR front wheel because I haven't been able to break it yet, but will probably get a haven to replace it when it finally dies.

Originally Posted by GoldenBear

Thank you for answering my question about rotor size. It does matter huh?

Oh god yeah. The exact same brake caliper on a bigger rotor is very noticeable......and spreads heat over a larger surface of metal.

Brakes squeal when something reverberates/vibrates. This can happen from warped rotors, rotors that deform when heated, gunk on them causing sticking that's uneven with the friction of brake pad material, or just some funky alignment with the caliper itself.

But a bigger rotor will reduce the effect of many of those factors.

Originally Posted by funkendrenchman

Why didn't I think of this? Oh wait, because it wasn't a problem the 50 times I rode them last summer or the first 20 days this year.

Well it is now, so you better figure something out

Your rotors are a different shape than they were 50 rides ago.

Originally Posted by kidwoo

Well it is now, so you better figure something out

Your rotors are a different shape than they were 50 rides ago.

If I buy a new rotor and it still makes noise, I'm sending you an invoice.

Originally Posted by funkendrenchman

If I buy a new rotor and it still makes noise, I'm sending you an invoice.

Send me your old rotor.


I don't mean it's fucked. I just mean that since you originally lined up the brake it's been through all kinds of heat cycles it hadn't been through, it's been under torque loads it hadn't seen yet......it's just a different piece of metal now.

Come on man, you've been riding bikes a long time, you know the things to check......alignment, bent rotor tongs........throw your front pads on the back just to see what happens........ You can figgir it out. But check all the things that don't involve money before you spend money.