So I thought I would get some lightweight disc rotors for my lighter weight wheels.

I’m running XT front and deore rear disc brakes.

I’ve fitted the lightweight rotors and my brakes became next to useless. The rear would barely work and even when un weighting it dragging it down a muddy slope it struggles to lock.

I thought it must have been the rotors so I’ve been and grabbed an XT rotor for the rear with a bit more meat on it and while the brake now seems better it’s still not perfect and the pads are squealing a lot under heavy braking.

Any ideas?

Do I need some new sintered pads instead of the OEM organic stuff?

Will take a few hard uses to let the rotor and pads bed in with each other…go find some watery mud and make sure the rotor is covered in it – ride the bike and brake hard a fair few times, the mud will help roughen up the rotor and pads to make them ‘mate’ well together and your braking will improve.

As above. Good few high speed stops & they will be fine.

I’ll give it a few more days. I’ve done a good 30 – 40 off road miles on these pads/rotors already. After reading some more posts on this subject I may check my alignments are right as well.

The mud is just an accelerant…you still need the high speed stops but the mud tends to help reduce them down to 6-12 hard stops instead of 20+ (from personal experience)…

Apparently pouring Coke onto them helps too.