Hi,

I recently posted a thread about my new hayes stroker disc brakes causing my bike to judder/vibrate when braking. It turns out (I think) that this is because the pads are making contact with the rotor below the rotor itself onto the rotor blades. Its only about 2mm or so, but I think that it is catching and causing uneven braking.

Does this sound about right?

If so whats the best way to cure the problem. I guess I could just use a small spacer to raise the caliper slightly in the mount taking it slightly away from the rotor. This would stop it catching but would also mean that the whole pad was not making contact with the rotor. That seems like a waste of power and is going to leave a big chunk of pad left when the rest has worn down.

Can anybody suggest any better ways of solving this problem...?

That shouldn't be a problem, I think your barking up the wrong tree there.

Fair enough! What could it be then? I mean I've already stripped the brakes down and realligned brakes and tightened hubs etc...

Interestingly I put in an old softer compound pad and the problem went away (at least temporarily as I road down the road and back) When I took the pad out there was a big gauge in the pad at the point where the disc overlapped onto the rotor blade.

If it's only 2mm then take the pads out and file a chamfer on the bottom edge so the rotor arms don't make contact.  If it stops the vibration then look into a permanent soultion like moving the caliper as you've suggested.

so it could be whats causing the problem?

A friend has just suggested that it could just be that the pads are glazed and need to be sanded down a bit - how does that sound?

To align the brakes, I put the wheel in with the callipers slightly loose. Put the brake on and tightened up the bolts. The wheel is spinning perfectly freely.

The same effect happened on both brakes within about 5 mins after about 3 hours riding from new. The rotors are also brand new so could they really have warped?

Ben Franks wrote (see)

so it could be whats causing the problem?

I doubt it but if you eliminate it then you can move on to finding the real cause, which is probably one of the things that MSP has mentioned.