Thanks for all the replies.
I think I'll try to get a Centerlock spacer/washer to rule out that my lockring is bottoming out before reaching the necessary clamping force to keep the rotor in place. The thin metal washer gets crushed when tightening down the lockring though, so I'm not convinced that's the problem.
I had the torque wrench calibrated last year. Both threads are clean and had a small amount of grease applied so friction in the thread shouldn't be an issue either.
Centerlock shims and a different style lockring are what's left.
Thanks for all the replies.
I think I'll try to get a Centerlock spacer/washer to rule out that my lockring is bottoming out before reaching the necessary clamping force to keep the rotor in place. The thin metal washer gets crushed when tightening down the lockring though, so I'm not convinced that's the problem.
I had the torque wrench calibrated last year. Both threads are clean and had a small amount of grease applied so friction in the thread shouldn't be an issue either.
Centerlock shims and a different style lockring are what's left.