Brake warping and judder

[C M Smith <cmsmith@domain.elided>]

John Fielding hits the nail right on the head.

Warped rotors are by no means the most common fault of disc brakes causing 
noise or juddering. John identifies the problem caused by not using the 
brakes hard enough periodically. Disc brakes require that some pad material 
be embedded in the surface of the discs for maximum braking efficiency. 
Uneven deposit of this can cause juddering. Sometimes you can actually see 
the difference on the rotor surface.

Another cause of this juddering is a floating caliper that doesn't. 
Cleaning the guide pins or slots (depending upon the floating design) can 
cure what otherwise seems a case of warped rotor.

Finally, the no wear ridge on the outer rim of the rotor can cause brake 
noise and vibration through the pedal. If the brakes are not used hard 
enough periodically then the edge of the pad can begin vibrating against 
the no wear ridge that is not wearing down evenly enough, due to slight 
movement of the pads in the calipers (there's no brake yet designed with 
zero clearance for the pads in the calipers).

Bottom line is, for safer brakes use them very hard periodically to keep 
them in tip top shape. If you aren't seeing any brake dust on the wheels, 
then you aren't using the brakes hard enough.

Cheers

Michael


Michael Smith
White 1991 164L
Original owner
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