[Old_Dude]

This is my first bike with disc brakes - I'm using a Manitou SXR (?) fork with Hayes hydraulic disc brakes & when I hit the front brake hard the fork shudders & shakes quite a bit - it's noisy too.
I'm thinking this can't be good for my fork. Is something wrong, or is this just what happens to front forks when a disc brake is used? Will this "go away" as my disc brakes are broken in?

Thanks very much,

OD

 

[KonaDude]

Check the tighteness of your headset, your front hub, your quick release. All should be tight, and with a disc brake your quick release should be tighter than usual.

If you've checked all that, you might have play in your fork. This is slop between the stanchions and the bushings in the lowers. Put your front brake on and rock the bike back and forth as if to check for a loose headset. If you see or feel any play between the upper and lower legs of the fork, that's your problem.

There will be some flex in all forks, and the combined play of anything with the slightest bit of looseness, so don't worry too much about it.

Also with a disc brake newly installed, check ALL the bolts. Disc brakes run pretty high forces on fasteners, so be sure to check that everything is tight.

 

[gtbike]

Also, Loosen the bolts to the disc and tightened them down evenly in a star pattern like on a car wheel then torque to spec. It is pretty easy to create "runout" of the disc by not tightening properly. Also check the fornt wheel bearings to see there is no side slop and lastly, spray your pads and disc with brake cleaner then lightly sand them a little to make sure there is nothing cauing them to grab.

 

[bomberz1qr20]

Originally posted by gtbike
Also, Loosen the bolts to the disc and tightened them down evenly in a star pattern like on a car wheel then torque to spec. It is pretty easy to create "runout" of the disc by not tightening properly. Also check the fornt wheel bearings to see there is no side slop and lastly, spray your pads and disc with brake cleaner then lightly sand them a little to make sure there is nothing cauing them to grab.

No brake cleaner, just rubbing alchohol is fine