Mountain Biking - Disk brake clearance issue

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View Full Version : Disk brake clearance issue


kleng
08-20-08, 11:42 PM
Hi

I've just replaced my old Giant branded MPH Disc brake system with the new Deore XT BL-M775 Disc Brake Lever and BR-M775 Disc Brake calipers, both front and rear are IS post mount 160mm disks. After following the set up instructions I can't get engough clearance between the disk pads and the rotor. This is even after pushing in the pistons and rebleeding the system and adjusting the caliper mounting/ angle on the IS post adaptor.

As I am reusing the old MPH rotors can anybody confirm whether original Shimano XT rotors would be thinner in width than the MPH rotors. This would account for the lack of clearance between the pads and MPH rotor.

Thanks for the help


mic2377
08-22-08, 07:42 AM
You may need to shim the caliper in the side to side direction. I believe shimano provides .2 and .5 mm spacers to accomplish this. You use them between the post adapter and the frame. This should alleviate all of your problems, however, it is trial and error to get it right.

I don't know anything about the MPH system... if the MPH rotor is much thicker this could be the problem. Maybe you could just head down a couple 35+ mph downhills and get on the brakes hard. Sometimes minor rubbing problems tend to be "self-clearancing".

Have you given any thought to the true-ness of your rotors? Maybe they are the right thickness but just aren't straight enough to clear the pads....?

Dannihilator
08-22-08, 08:14 AM
Replace rotors as well and problem should be resolved.


kleng
08-23-08, 09:25 AM
Thanks for the advice, I'll replace the rotors and look at the spacers.