Hope Tech X2 Problem
So I have always had a problem with an X2 rear brake running a 160mm Hope 2-pc rotor. It has always been rather noisy and also, when braking very hard, causes a vibration that resonates through the entire rear end and bike. I never could figue out what was going on with it or fix it despite trying different brake pads (both semi-metallic and organic). After inspecting it the other day, it appears that the caliper is sitting too low on the rotor, and thus causing the pad to not fully engage the braking surface of the rotor. It appears that the pads are engaging partly on the "arms" of the rotor (possibly even touching the rivets in the Hope rotor) which is causing the "unevenness" leading to the noise and extreme vibration. Attached picture shows the braking surface of the rotor and you can clearly see where it's contacting the rotor. Notice the braking surface is sitting slightly below the top of the rotor and continues to the "arm" of the rotor. I also looked at some other Hope brakes on other bikes and they don't sit this low on the rotor (and thus, don't have the same problem).
Has anyone seen this or heard of it before? Could it be a manufacturing defect with the caliper?
Probably just your frame. Not every frame is exactly a 160mm IS mount.... nor the same angle.. etc..
Just throw a couple washers under the caliper, see if it stops.
i started having the same issue after installing the 160mm 2 piece rotor on the rear of my bike. my braking track is just a bit below the surface (1-1.5mm or just barely into the set of holes right above the rivet) but it was the same on the standard rotor i replaced which had zero issues so i figured it was not due to that.
after messing with cleaning and resurfacing the rotor and pads (organic) i finally took the time to reset the pistons and center the caliper perfectly to make sure both pads contact the rotor at the same time. i still get a bit of noise at very slow speeds (and it seems to be slowly disappearing as they bed in) but the resonating seems to be gone. i may still shim the caliper up just because but i don't see it making much of a difference.
the other thing to check is your suspension pivots if you have any. my bearings are almost shot and my rear end feels a bit flexy at times - i figure anything that is not tight can play into the resonating issue with the pivots getting worked under hard braking. a combination of anything not exactly right can cause issues.
with your braking track i'd definitely spacer it up though - that's quite a bit off.
I had this same problem with my Avids, and a washer under the mount worked perfectly.
Originally Posted by Borgschulze
The more you ride, the easier it gets........
the easier it gets, the more you ride.
I agree with adding a couple of washers to raise the caliper so it contacts the rotor correctly. Re-centering the caliper is a good idea too, but I couldn't get rid of the "shutter" on my X2's until I got rid of the Hope pads. I tried both the organic and sintered hope pads in dry and wet conditions and could never get them right. Switched to EBC organics and have never had the problem again. You would think that the OEM pads would be the best for that brake, like Maguras are, but IMO the Hope pads are just crap.
If it were me, I would build up the caliper with enough washers to get it braking on the rotor track, and also reset up the brakes, making sure to centralise the pistons/rotor. That should solve the issue.