Bicycle Mechanics - Yet another squealing brake problem...

Hello to all........Here's my set-up: GT XCR-4000 bike with RockShox Judy fork, Mavic 521 rims & Shimano XT parallel-push brakes. Problem: I'm going deaf!!!!! The front brakes squeal so loud it's embarassing. I tried toe-in, toe-out, no-toe, toe-up, toe-down, deglazed the rim (scotchbrite) and sanded the pads. I checked all mounting bosses and linkages for play and there ain't none. Replaced the cable and housing, increased the spring tension on the caliper and even installed a brake booster. I flipped the wheel over to run it in the opposite direction and even swapped the pads off my daughter's Huffy. No luck! It squeals on anything more than light pressure on the brake lever. Funny thing is....the rear brake is set up exactly the same way as the front and not a sound from it. I have Koolstop dual-compound pads on order but for now it's really pissing me off. If anybody has any OTHER suggestions I'm wide open.

I have no answer, only sympathy. I can't think of anything that you say that you haven't already tried. I kind of think it's like raising kids, the only people who are sure they know how to do it are people who either don't have any kids or whose kids are safely grown. If it's driving you deaf, I think I'd try a different set of brake arches and see how that goes.

The Kool Stop pads will silence that. Stock shimaNO pads are garbage.

I have Kool Stop pads and they squeal. But I don't care. :p

You might try using something more abrasive on the rim.I have used emory cloth to stop squealing on new bikes when nothing else worked. The roughened surface seemd to keep the pads from chattering. Improved grip as well.
I tar my trials rims and you can hear them two blocks away.

This may sound like a strange idea, but it worked on a cantilever brake on my cyclocross bike that was giving me fits. It was an Avid Shorty 4 with Kool Stop pads. The rear worked fine with a slight toe in like it should be, but I tried almost as many things as you did for the front, and what ended up working for me was to toe in slightly one side and toe out slightly on the other side. Worked like a champ. YMMV.

Oh, and what's funny is that I had Shorty 4's on another bike that worked fine(different rims though), but i was almost thinking of swapping brakes between the bikes, but it didn't need to come to that :)

Thanks everyone for the responses. I took a 32 mile ride yesterday with some spots at a steep downhill. I'm so upset with these brakes that I thought I'm going to fry these pigs and see what happens. They sqeauled all the way down and got super hot but the hotter they got the less squeal there was. I'm trying to glaze the pads so maybe they might slip a little instead of being so grabby. No luck! As soon as they cooled off it was back to squealing again. When I get my KoolStop dual-compound pads I'll post again so everyone can get the results. Thanks again to all.............JimB

I once got a cleaner on my rims, that I used to clean my cassette. OT stop it from screeching I gave it a good rub down with a cloth and a powerful citrus degreaser, then took it up to the hills and brought it to a screeching halt a few times from 60/70kmh.... was fine after that till I got cleaner on them again!

Brendon
:beer:

What a coincidence......I just got my KoolStops today in the mail from Harris Cyclery and rushed to put them on. First I followed the instructions and installed them with a little toe in, followed by "zero" toe, and then with some toe-out. The S.O.B. squealed again, and this time there's also some chattering. These pads are really grabby and stopping power is awesome. I got sandpaper and roughed-up the braking surface on the rims...no luck! I think I will try taking off the XT parallel-push calipers and putting the Avid single digit calipers back on just to see what the hell is going on. Anybody know of a good priest that can do an excorcism on my bike.......I really think it's possesed!!!! I also have a crap-load of brake pads that'll probably last me a lifetime.

Take your bike to your LBS and have them set up your brakes. I hav enever had a problem with Kool Stop pads squaling, except in the rain. The red or salmon compunds from Kool Stop usually are very spot on with no problems at all.

JimB - I feel your pain. I used to have a set of the Shimano XT brakes...oh my, they squealed like pigs. I thought I read somewhere about the parallel linkage being the cause, but I eventually gave up trying to silence them. I ended up buying a set of XTR v-brakes and have been happy since.

BTW - if anyone wants a set of Shimano XT v-brakes (used a couple of times), let me know....i will part ways with them real cheap ;-)

- Paul

I'm ordained, If you want to bring it to Raleigh, I'll take a crack at it. I've never really done much casting out of demons tho, as I am comfortable with the ones I have.

LOL!!! -- That's quite a distance to bring my bike so I think I just might offer it as a sacrifice to the volcanoes over here. With my luck the lava would probably "squeal" as it oozes out. I'm going to put my original Avid calipers back on and see (or rather hear) what happens. Will keep everyone posted with the results.......JimB

If you want you can fly me out. I will put up with some hardship to help a brother out.

I have the exact same problem with my XT Vs. I've tried everything and so far my best success is with a hard compound Fibrax pad. Usually they will be OK but hard braking on a fast road descent will get them hot enough to start the squeal again. They are fine again the next day.

I did get a shim kit for them but it didn't fit, as mine are a later model than the kit was for, and supposedly my model didn't have the squeal problem and so there is no kit for them. I am going to try to drill out the shims and make them fit, or it just may be time for a disk up front.

I will check out those "Fibrax" pads on the 'net. Seems like I need harder pads to stop the squealing. Mine are just the opposite though........when I fry them they get quiet and are noisy when cold. Last nite I did some experimenting: first put on my old Avid single digit caliper with Shimano and Koolstop pads but still squealed. Just for laughs I took the caliper off my kid's Huffy and put it on but still made same noise. I have come to the conclusion that it's my rim that needs some work. The wearing surface is maybe too smooth. I've tried Scotch-brite and #400 sandpaper so far. I hate to screw up the anodized finished on my Mavic 521D rim but no sense it looking nice and performing ****ty. I will reinstall my XT caliper with Shimano pads as a baseline and move up to rougher sandpaper and see what happens..................and the saga continues.

the owner of my LBS said that grooves around the braking surface can cause squealing, somewhat like a record player (remember vinyls :) )

The shim kit I got from my LBS was a factory fix for the squealing but only fits BR-M739 Vbrakes. My brakes are BR-M750. If yours are the earlier part you should be able to get this kit and it may help. It was only $5 AUD.

Thanks for the info. Here's what I'm trying out: I thought about the brakes on my truck and noticed that when the brake pads seat-in they have a natural shiny glaze as well as the disk. When I sanded the pads on my bike they became very grabby so I thought what if I put a glaze on my pads? I took a small piece of metal and heated it up with my propane torch and ran it across my pads to lightly melt the surface of the pads to produce a glaze (I have lots of extra pads to experiment on). I slapped them on my caliper, adjusted them to a slight toe-OUT and rode around my driveway. I couldn't believe it........NO SQUEAL!!!!!!! I tried a slight toe-in and zero-toe but it produced a small squeal. I am riding to work this weekend (about 30 miles) and will update this post with the results. I hope this works as I'm out of ideas. If it doesn't..........hello disk brakes!!!

My Raceline has squeaky rear brakes, but I don't mind. I normally use mostly the front only, and jst a bit on the rear when needed. When I'm riding in a pack or pace-line however, I'll use the rear brake more just so as people know I'm slowing, as it makes a HUGE noise!

Don't get me started on Shimano.

Change the pads.

Rode in to work this morning (my boss is at a meeting right now) and the front brake only squeals when it's cold. After about 75 feet of braking the squeal goes away but returns when the pads cool off. I think this the best it's going to get. I will try my idea on my KoolStop pads (glazing them) (see above post) and see what happens. As far as the stopping power after I "glazed" them there is absolutely no difference. Still seems weird that the rear brake is running great with NO squeal what-so-ever. I wish it was the other way around as I do most of my braking with the front.

I'm still riding old stuff (I mean old, Mafac brakes on my Peugeot UO-8. I DO have a Trek 520 with modern components, too).

Anyway, in those old days, the method for eliminating brake squeal was to slightly toe-in the brake pads at the end toward the front of the bike. I assume this would still work on the modern stuff. I can't see why it wouldn't. The brakes on my 520 are not squealing, so I have no experience trying to get rid of it on the Avid Single Digit 5 on that bike.

I already tried adjusting some toe-in into the pads..........along with no-toe, toe-out, toe-up, toe-down. I have Shimano XT parallel-push calipers which replaced my old Avid single digits. I think I will run the current set-up I have now (see above posts) and hope that the pads will seat-in a bit. The squeal now is a lot less than before but will still re-try the KoolStop pads. Thanks for your input!!!

i had the same problem when i got my gt! I find that ex v brakes do tend to squeal, I changed them out to avids and all was good, then i went hope m4/3's and im in heaven

oops thats supposed to be xt v brakes

Right now the brakes are running good with all of the modifications I did. They only squeal slightly when the pads are cool but once they warm up they're dead silent. I tightened everything down real snug and I ain't messing with them because I think this is the best they're going to get.

cool good on ya mate! Its funny up here in whistler its kinda good to have squealing brakes it scares the bears away!

I just had a thought.....I have Mavic 521D rims on my bike. Does anybody know if these rims are ceramic coated? When I was sanding the braking surface I did notice a white powder (hopefully not anthrax) coming off. I don't know what ceramic rims look like, mine look like a dark gray anodized finish with some kind of clear coating over it. If they are ceramic then I'm using the wrong pads and it might be the cause of my squealing.

I know getting rid of a noisey brake can be as simple has taking a cresent wrench and re position the brake pad some what?experiment

I take a cresent wrench and force the brake pad into a new positon,you'll be surprised how easy they can be forced with a little english on the wrench.Sometimes times that is all it takes is a little re positioning and no more squeak?

Wouldn't that be doing the same thing as adjusting the toe on the pads? I hate to screw-up my XT calipers by bending stuff. I did try extreme toe adjustments with the pads. Would using regular brake pads on a ceramic rim cause a squeal?

Same problem as all of you. Installed new front and rear XT V-brakes with ceramic rim surface and the squealing would not stop. Toeing in the pads did not help either.

Just found out that Shimano makes a special pad for ceramic surfaces.

http://www.performancebike.com/product_images/400/00_1762.jpg

http://www.performancebike.com/shop/Profile.cfm?SKU=551

I had this same problem, that's what brought me here in the first place. I cleaned my rims and sanded my pads a little to try and improve braking performance. Next day I was squealing down the street like a car with fan belt issues. I came here and tried all these things (citrus cleaner, alcohol, sanding...), other than replacing the pads (my budget is very limited). Finally I had enough. I spun the rims with the bike upside down and applied pressure to each pad individualy to figure out which ones were actually causing the noise. Then I took a pencil and held it against the rim for a minute while spinning it. I repeated this a couple of times, test riding the bike each time. Presto, no more squeaky brakes. (Stop spelling it breaks) This could be done much easier with a tube of graphite but I didn't have any. I know everyone says don't lube your rim. I agree, don't use WD-40, Tri-flow or anything like that, but I haven't noticed any difference in stopping power with the graphite (pencil lead) and even if it did affect it in some small way it is worth not having my bike scream at me whenever I stop.

I've never been able to get KoolStops to be quiet. Avid Pro 20's work for me. Never a squeal. bk

My Kool Stop Eagle 2's squealed when new on my Mavic Open Pro Ceramic wheels. So I braked hard to set them a few times, and it's only a mild squeak now under strong downhill stops. Interesting your trick though. I'll keep that one in reserve.

The cost on the special brake-pads for ceramic rims, and the stories of how quickly they disintegrate, did not justify the purchase in my opinion. But whatever works for you - by all means go ahead. It's one of the costs of having funky, gritty rims on your speed-demon.

EDIT - I stand corrected. The Shimano pads aren't to bad price wise. But from the review, they also don't work! LOL! At least the guy didn't shell-out $50 for the Swiss Stop pads.