Just looked at the brake rotors on my Process , rear one is looking Scarey thin , ordered a replacement , will get my tin hat on waiting for the ” stop dragging the brakes ” comments ! 18 month old Shimano SLX RT66 rotors . 😳

One of the manufacturers has a minimum thickness stated in the manual somewhere.

I tend to go for 2/3rds of new thickness.

Get about 2 years out of the ones on my most used bike and i’ve never worn one out on a race bike.

1.5mm min on Shimano rotors. Measure with micrometer. Using Metal pads wears them down quicker than resin ones.
Only noticeable problem with running them right down is increased squeel and tendency to warp with heat build up, perhaps increased lever throw.

If in doubt change it – this is Stevo from the Whiteroom just after his rear disc failed while decending in the Alps in September, he’d changed the front because it was worn thin but thought the rear would be alright for a few more rides!

Hope say 1.5mm. Watch out for some rotors with some Kevlar pads, they can noticeably dish the braking surface.

Disks wear out? Who knew?

(rushes off to check 15yo disks on MTB tandem…)

18 months!! just shows how gritty the Quantocks are. 🙂

they wear out?
Mini rotor on front of the M2, still there 15 years later 🙂