New Disc Brakes - Do They Always Sound Like This?

cannonbong said:

Hi,

I got a new bike recently (Scott Sportster P55)... anyway, it's got Disc Brakes, which I've never had on a bike before...

Out on the road, I don't here anything, but back home during maintenance, when I spin the wheel you can hear a 'brushing/whisping' sound (click link to see video)

62218686.flv video by photo-d-u-m-p - Photobucket

It could be something I'm doing wrong, as I'm more-or-less a beginner when it comes to bike maintenance... I don't have a proper work stand, so my current means for installing the wheels is to turn the bike upside down...

Putting the wheel on, I just slot it into the wheel cut-outs, then tighten back up the quick-release bolt... But, no matter whether I let the wheel rest back into the cut-outs or try and manouvre it a bit, the end result, when I spin the wheel, is there's still that brushing against the brake pads in the caliper.

Thanks,

Graham.

Mechanical discs move only one pad. It's important to adjust the caliper so that the rotor is close to the stationary pad. Rotors are all a little bit 'warped', not flat. If you adjust the caliper close to the inner pad, you may get some rubbing, noise. Not uncommon with bicycle discs, even hydraulic ones. Your caliper has some tilt, in and out adjustment. Make it as close as possible, hopefully to reduce the noise but if you put it too far, you will reduce your braking response.

Peter@vecchios said:

Mechanical discs move only one pad. It's important to adjust the caliper so that the rotor is close to the stationary pad. Rotors are all a little bit 'warped', not flat. If you adjust the caliper close to the inner pad, you may get some rubbing, noise. Not uncommon with bicycle discs, even hydraulic ones. Your caliper has some tilt, in and out adjustment. Make it as close as possible, hopefully to reduce the noise but if you put it too far, you will reduce your braking response.

Thank's for the help Peter and the correction about there being only one moving pad...

I had a go at adjusting the inner pad, so that's something more I've learnt, thanks to you.

There's still a slight rubbing on the brake pad... this is due to a bit of lateral movement when the wheel spins... it feels fine to ride, but the movement is noticable... it'll have to do till I get it checked out by the shop.

Graham.

cannonbong said:

Thank's for the help Peter and the correction about there being only one moving pad...

I had a go at adjusting the inner pad, so that's something more I've learnt, thanks to you.

There's still a slight rubbing on the brake pad... this is due to a bit of lateral movement when the wheel spins... it feels fine to ride, but the movement is noticable... it'll have to do till I get it checked out by the shop.

Graham.

There are tools to help to straighten rotors. All are a little out of plane and as they wear, get hot, etc, maybe more so. They are so thin, tough to keep them flat.

Peter@vecchios said:

There are tools to help to straighten rotors. All are a little out of plane and as they wear, get hot, etc, maybe more so. They are so thin, tough to keep them flat.

What do you do when/if you get this sort of thing happening?

Just had a check online... found this webpage from UtahMountainBiking.com: Disk Brake Rotor Precision Truing ... are these the tools you mention?