Originally Posted by neversummer78
I believe that M6 rear brake is the same as non M model. Only the front is different, so I think it should fit without modification.
I don't believe that's right.
I want to say even the non-ceramic brakes on the M6 are bigger at the rears.
The 6er rear disks are something like 13.6 inches. The standard M6 rear disks are something like 15.6, and cross-drilled of course.