Rotor rubbing only when accelerating

Darryl_1983

Fitted my new Shimano M595 brake last week with 160mm rotors front and back.

Going from BB7's with 203F/160R, I needed a bit more power, so ordered myself a set of alligator windcutters, (203F/180R) the 203 rotor vibratored/juddered, so had to send that back for a refund.

Then tried a set of Superstar Vibe (203F/180R) the front seems ok.

But the rear seems to rub pretty bad whenever i accelerate, tried to refit the 180 Alligator now that does the same. So had to go back to the 160 rotors, But it's doing it with that too (only slightly with this however). Yet there is no rub at all when i set them up and it doesn't seem to be too bad then free rolling. Had 4 different rotors on the back now, anyone got any ideas?

*AJ*

Tighten the rear QR a bit more, and re align the caliper....

Darryl_1983

I've already tightened it up as much as i can, as i though this might have been the problem.

02gf74

as you may have figure out, there is movement between the rotor (fixed to axle) and the caliper (fixed to frame) so either the axle is flexing or the frame is flexing.

A larger diameter disc will highlight the problem.

Is your bike rear suspension? Can you check there is no play in the bushes?

Also check the rear axle bearings are adjusted correctly.

If no luck, eat fewer shredded wheat.

nicklouse

and let them bed in.

Darryl_1983

Bikes a Commencal Combi (2005 hardtail) Never had any issues before, but always used 160mm rotors.

Don't suppose anyone knows if these are flexible frames or not? Oh i'm a leanish 15 stone.

Running with Shimano XT hubs.

sparky.2002

slacken all caliper bolts, hold brake lever in fully and then retighten caliper bolts. This ensures the rotor is sat smack in the middle of the caliper. Hope this helps