ak_foxtrot

Can anyone recommend any good degreasers for disc brakes? I've tried using isopropyl alcohol to stop the constant honking that I hear when I use my rear brakes, but it hasn't helped at all and seems to have made the noise louder. I was told by some people at my school's bike shop that it's normal (it's a new bike), but it hasn't gone away. Thanks.

vasracer

Check the adjustment of the caliper. If the brake is not properly positioned that could be the cause of the noise.

Marrock

If it's new it could also be the leading edge of the brake pads chattering against the disc, not much to do for that except be patient till the pads are worn in a bit.

ak_foxtrot

The brake seems properly positioned. There is an even amount of space on either side of the disc also. The "honking" starts when I apply just a little bit of pressure on the disc.

Marrock

That's definitely pad chatter then, if it happens with just a bit of pressure and then stops when you really clamp down on them.

It's the same thing that makes disc brakes on a car squeal.

ak_foxtrot

wait - on further inspection i noticed that the disc is already against pad nearest the axle.

wrench

Put the disc in the dishwasher next time you do a load to decontaminate it. Disc Brake cleaner is ok but a dishwasher is better!!
Ensure the springs that hold the pads apart are at full strength to prevent 'pad chatter'
Don't be tempted to put anti-seize or Coppaslip on the back of the pads.
You could try a sintered metal compound pad. They are usually quieter.

nadimk

That is probably fine, depending on the model. Sometimes the inside pad is fixed and the outside pad moves in toward the rotor when the brake is actuated. The outside pad may be worn, so you can move it in, but you need to know how to do this properly depending on the model. If there is a lot of space, the rotor bends a lot and may become noisy. Don't use anything other than denatured isopropyl alcohol to clean the rotors...or maybe soap and water. If you have an LBS nearby, take it in and have someone experienced look at at. Don't take chances with brakes.

Marrock

I use lighter fluid to clean mine, takes mung off in an instant and evaporates just as fast.

tellyho

Not sure if I can avoid sounding smartass here, but what about brake cleaner?

madman451

We use Finish Line Speed Clean Degreaser (spray then let dry(it dries with no residue)- wipe if there is visible dirt). Afterwards I usually ride the brakes hard for a block, the brakes will squeal at first then stop by the end of the block. You may want to spray the pads as well.

AJU

I used automotive brake cleaner on my discs once and the first ride (more than 30-40 minutes later) left me without brakes. Levers to the bars and practically nothing. I had to run downhill with the brakes on for some time before braking power gradually came back. Not sure what happened, as that stuff should be ideal (I can only guess that the pad material reacted with the cleaner).