Mountain Biking - Noise from disc brakes

[FONT=Arial]I just purchased a Bianchi mountain bike with disc brakes. The first few rides were fine but then I came up with a screeching sound form the rear wheel. The bike shop says the disc brakes are acting up due to the cold weather. Has anyone had a similar experience? :D ;)

Has anyone had a similar experience? :D ;)

Yes. Quite annoying, eh? I haven't found really any way to completely stop them from squeaking when they really want to.

I don't much about bicycle disks, but in cars, organic brake pads are less noisy at low temperatures than semi-metallic or metallic pads. Do you know what kind are used?

No problems with mine during semi-cold weather.

[FONT=Arial]I just purchased a Bianchi mountain bike with disc brakes. The first few rides were fine but then I came up with a screeching sound form the rear wheel. The bike shop says the disc brakes are acting up due to the cold weather. Has anyone had a similar experience? :D ;)

Yeah, me too on the Hayes hydros. But it's my front brake on my newest bike, bought in early October which still has less than 10 hours of riding on it (hey, I've been busy!).

I guess it's still in the break-in period.

The rub was quite bad at first causing resistance against the wheel turning. As you say, it was "screeching" while I rode. Quite embarassing as other people would think, "what a piece of junk!"

The fix:

I loosened the brake on the mounts on the forks, then stuck thin cardboard on either side of the break shoes and disk, squeezed down on the brake lever, tightened the mount back on while still squeezing the brake, then let go of the brakes and removed the cardboard spacers. This re-aligned the brake pads.

It's usually silent but I still get a bit of break rub sometimes, especially if I pop a wheelie. It comes and goes intermittently. Doesn't screech anymore though. Just a metallic ringing sound the odd time (usually after my front wheel comes down after a wheelie, a bunnyhop or something to jar the bike a little), or after riding in wet conditions. Maybe I just need time to break the damn thing in.

Damn work before pleasure... :(

If your rotor squeaks occaisionally during riding you may have warped discs. Mine squeaks intermittently because the rotors are warped. Your pads or rotors may be contaminated as well causing it to squeal.

I just purchased a Bianchi mountain bike with disc brakes. The first few rides were fine but then I came up with a screeching sound form the rear wheel. The bike shop says the disc brakes are acting up due to the cold weather. Has anyone had a similar experience? :D ;)
of the two sets of disc brakes i got, my magura julie hydros squeel the most, the front brake is perfectly fine, but the rear screams like a banshee when i apply them, especially on downhill sections.

my hayes mechs (which are newer than my maguras) squeel a bit from both the front and the rear – the rear more than the front, but that’s really only when i apply them lightly. they probably just need a bit of cleaning.

usually, disc brakes need a bit of time to break in, and because i generally use the front brake more than the rear, the rear takes a lot longer to break in than the front.

you’ll also get a little bit of rubbing while riding here and there. it’ll come and go. i think this is kind of normal. the only other “weird” sounds i get from my brakes usually come when i’m riding in the rain or if i’ve just gone through a puddle or something.

my avid mechs squeel in wet conditions and they are well broken in already... can't figure it out

My Hayes hydros squeel in all conditions. I've tried everything in the book to quiet them, without success. It really doesn't bother me that much though. :/ All I care is that they stop. Now, when my other bike's rim brakes squeel, that bothers me, because it means they aren't working very well, errrrr. :(

A few things you could try, as mentioned check the discs to see if they are warped, clean them to be sure they are not contaminated and chage the pads.
You might have sintered or pads with more metal in them, try some organic pads.
Also, remove any paint between the mounts on the frame and the calipers. Be sure that the disc is running stright and the caliper is centered on it.

Some brakes will also squeel more when they heat up. If you are riding the brakes alot that could also be your problem.

Lastly, some brakes will always squeel and you will have to get used to it.

:beer:

Plenty of good suggestions, here's my cheap and quick fix. Swap the front and rear pads. Sometimes the pads and rotors wear into a particular pattern that causes squealing and just swapping the front and rear pads takes the pads and rotors out of the squeal inducing alignment they were in.

It only works about half the time in my experience but it's free and only takes five minutes so why not give it a shot?

Plenty of good suggestions, here's my cheap and quick fix. Swap the front and rear pads. Sometimes the pads and rotors wear into a particular pattern that causes squealing and just swapping the front and rear pads takes the pads and rotors out of the squeal inducing alignment they were in.

It only works about half the time in my experience but it's free and only takes five minutes so why not give it a shot?


good way to get more life out of the pads ;)