took the ccm for MOT last week failed due to warped front brake disc, had it on the brake rollers and the needle was up and down quite a lot, fair enough

ordered new disc fitted and and with a DTI on the disc have 10 thou of variation on the new disc

booked in for retest later today, but just wondered if there was a "warp limit" i can quote if he fails me again?.

cheers
Ray

Disc run out should not exceed 0.1mm or 25 thou. The problem that gives judder or uneven braking effort is more usually thickness variation which should not be more than 0.01mm over 8 points in the middle of the disc 45° apart.

It's the runout that eventually causes the thickness variation over time and mileage.

haynes z1000 states 0.3 mm max.

like most things test related excessive is the term used not actual measurements if the it feels ok on the road i doubt the bike rollers will pick it up as they only turn at a few mph