fopianki

Hi folks, I just purchased a Scott mountain bike with disc brakes. The first few times I road it I would start hearing and intermitent squeeking coming from the rear brake area which would stop for about 30 seconds after I briefly squeezed the rear brake lever. Now I'm getting a rubbing sound...kind of like when you wet your finger and rub it around the top of a crystal glass. It doesn't start when I first ride...it take 5-10 minutes before it starts and it goes away briefly if I squeeze the rear brake lever. It also kind of "fads away" if I stop pedaling and just coast.
I know nothing about disc brakes, the shop I bought the bike from is 3 hours away and the manual is useless! Is this an adjustment issue that is easy to handle? Are there any on-line resources I can access for disc brake maitenance? Help!!!! Frankp

pmseattle

It sounds like one pad is just barely brushing against the rotor. What brand of brakes does your bicycle have ?

mtbikerinpa

usually, disc pad centering is a simple enough operation if you have patience and a good eye. It may take some practice at first(depending on the brand) but I cannot say what the method would be without knowing which it is.

fopianki

I have Shimano BR-M405 mechanical brakes. Interestly, when I went down to look at the brakes I found that if I held the bike vertical and barely moved it I got a pronounced rubbing sound. If it is the brake pad...is it easy to adjust myself? thanks for your feedback Frank

mtbikerinpa

I have not directly worked on that model of shimano brake, though mechanicals tend to operate roughly similar to one another.
1st make note of your cable feel at the lever for reference purposes in case it changes. Next, with the bike inverted(you may do it upright if you have a stand but the wheel needs to spin freely), spin the wheel slowly. If there is any rubbing it should sound like a slight slicing noise.
There will be some form of adjuster to compensate for this effect. Some use a screw on the side of the caliper, inline with the pad mechanism, and others(many hydraulics too) will use the mounting bracket slots. If there are no fasteners or holes for allen keys(usually small ones) then it probbably will use the caliper mounting bolts as the adjusters. These will be mounted 90 degrees to the angle of the axle.
For centering this type, loosen the bolts just enough to allow it to wiggle. Next, grab the lever firmly and tighten the caliper bolts. Recheck for rubbing. Lather, rinse, repeat until satisfied.
For the type with side adjusters, insert said allen-key into said hole and turn gently. If it does not want to go with relative ease, double check that it is in fact an adjuster. Always remember how many turns you made to the adjuster until the desired result is achieved, as rabbit-trail insurance. Some side adjuster models use a thumb-screw as well. When you get down to it, one principle applies. Be observant, be careful, and you will be able to figure it out.

fopianki

Hey, I really appreciate you taking the time to help out a total stranger...and a Hoosier to boot! I'm riding my road bike in the Sunstroke 74 tomorrow and then on Wednesday morning I'll tackle the disc brake in the cool of the morning...I'll let you know how I do! regards Frank