Disc brake service/maintenance

[orgasmicliving!!]

I just took my mountain bike for a ride and the brakes squealed the whole way. I don't mean just when I applied them, rather the whole time that the rotor rotates through the caliper, ie all the time that the front wheel is turning. It was quite annoying!

So, any tips on how to make the pads sit further apart, or anything else I should do to make this horrible noise go away?

The bike is a Cannondale Rush 800, with a single-sided front shock called a Lefty.

Thanks!

Edited by orgasmicliving!! on Monday 28th August 05:05

[Locoblade]

What brakes do you have fitted?

[orgasmicliving!!]

Shimano LX

[Locoblade]

I think the LX are very similar to my XT calipers, in which case there isnt really a way you can adjust the clearance. However, they only usually squeal if the pads have got contaminated (with oil etc) or sometimes if Ive been covering the brakes quite a bit but not using them that hard, so the pads glaze a bit. First off try taking the pads out and giving the pad surface a quick rub with a fine sandpaper and clean the discs with a proper disc brake degreaser, then see if it improves. You could also try a smear of grease on the back of the pads to see if that helps, although be careful it doesnt get on the discs or front of the pads obviously!
Failing all that I'd replace the pads as if they've become contaminated they can't usually be salvaged

Edited by Locoblade on Monday 28th August 16:53

[orgasmicliving!!]

OK, thanks. I didn't think there was a way to adjust the clearance, but I wanted to be sure. Yeah, I am suspecting glazing. I will take it in, as it's under warranty. It felt really heavy going up hills yesterday, so I suspect the disc may be dragging on the pads, and I don't see anything to adjust.

Edited by orgasmicliving!! on Monday 28th August 18:54

[rico]

You can take a light file to the pad to take off the surface glazing if thats whats happened.

Might help

[orgasmicliving!!]

Thanks for all the help, guys. I took the bike in today, and the guy did some fidgeting after loosening a couple of screws on top of the calipers (they are mounted with oblong holes, so can be repositioned if the screws are loosened) and the noise went away. So it was just a case of poor adjustment/assembly. The bike feels a lot easier to ride, so I guess it was more than just a case of the rotor "kissing" the pads, it was actually dragging. I can't believe I rode 24 miles like that the other day!

Edited by orgasmicliving!! on Wednesday 30th August 19:17