front brake drag

[rz500guytexas]

I use EBC GPFX pads on the track bike. My wheel spins like no calipers are installed. I twice a year, depending on use, clean the pistons and calipers. Do the same way as someone else mentioned. I get all of the piston pushed out individually past their normal working distance. Takes a bit of time to get them all out the same and clean with simple green and a stiff tooth brush. After a good clean i apply a small amount of brake grease around the pistons and slowly push each back in the same distance. Wipe any excess grease from pistons. Then I will shim both calipers so all pistons are same distance out and bleed. Make sure the little bleeder is clear in the master cylinder. I use Motul 660 in the TZ and 500. I believe the higher the boiling point the more likely the fluid will absorb moisture. I am in Houston always having high humidity. A drier climate might not need same maintenance schedule. I flush the fluid yearly unless I see discoloration sooner.

There are also steps in installing the axle and brake calipers in the proper sequence to be sure the wheel is centered in the axle and also to be sure the calipers are centered on the rotors. Some calipers do not have alignment pins when bolted and can be off center or angled if not installed correctly.

Watch this DAVE MOSS VIDEO. https://www.youtube.com/watch?v=DYHV78tWs1c

Both bikes are stopping from 136 MPH to 40 on back straight at COTA. I have seen up to 1.2G on the 500.

[wolfgangh]

Hi, thanks alot for the detailled feedback.
Calipers are freshly rebuilt, I cleaned polished the cylinder and pistons, put all new seals in and used a very thin coat of brake caliper grease. I did find the root cause today: the calipers are not centered on the rotors, the have contact to the discs at the inside. Now, I was curious how this can be. Since I have a second icentical stock bike, I compared all distances between the 2. Distance between rotors and rotor thickness is identical. Distance between rotor outside and fork leg is identical. Distance between fork legs is identical. So the only difference can be in the caliper mounts on the fork leg or the caliper itself. It is easy to correct - I just put a 0,5mm - 1mm shim between fork leg and caliper. If I loosen the caliper bolts to allow some free play between caliper and fork, the wheel already spins freely. It will remain a miracle though.

[bruceco]

I just joined the forum and wondered the part numbers for both front and rear rebuild kits for the calipers and ebc pads.I am in canada.