Shaving Rotors

[BEAR-AvHistory]

Its my understanding the rotors are "soft" & the shiny is the rotor being polished down. Don't think I ever had a BMW pad change without a rotor change.

[Speed25]

Originally Posted by fe1rx

I agree it is sometimes appropriate, but given the aggressive wear characteristics of OE pads, probably only if you are using a pad that is much easier on the rotors. In my experience, one set of OE pads wears a bit more than half the usable rotor thickness away (given my driving), so a second set would take the rotor very close to or below the minimum, even without turning. If that is your situation too, it would be better to replace them rather than turn them.

Also, the concentric texture of a turned rotor is not ideal. Rotor faces should have a random texture, hence new rotors are ground not turned. Turned rotors shouldn't be used "as turned", they should be given a random texture with a sanding disk.

If the pads wear the rotor so fast, what difference could the slight surface texture possibly make? My wife's old e46 once sat for a month and rotors got rusty. One mile and three stops later I got out and looked; back to shiny. It's nothing like cross-hatching a cylinder bore.

[fe1rx]

Originally Posted by Speed25

If the pads wear the rotor so fast, what difference could the slight surface texture possibly make? My wife's old e46 once sat for a month and rotors got rusty. One mile and three stops later I got out and looked; back to shiny. It's nothing like cross-hatching a cylinder bore.

You make a good point.