The minimum thickness of the rear brake disc is 4 mm.
If the disc thickness is less, it must be replaced. If the disk is bent, has cracks, chips and other mechanical damage, it must be replaced.

Removing
Removing the brake disc is done with the rear wheel removed from the motorcycle (see «Rear wheel - removal and installation»).
1. With a 6 mm hex wrench, unscrew the four disc mounting bolts and remove the disc. The operation is similar to removing the front wheel brake disc.
Installation
Before installing the disc, treat all mounting bolts with an anaerobic thread locker. Tighten the bolts crosswise to a torque of 42 Nm.