I've seen these also...obviously good against surface rust. I also read that another company claims the plated brake rotors are bad on the bearings! Is there any truth to this? Should I be buying Zinc plated or raw? Thanks...

 

I read once where this guy thought that because the brake pad contact surface rusts on his zinc plated rotors after a few weeks of sitting outside that it means the plating doesn't work.

Wouldnt they plate the raw casting before the machining?
The bearings run in a race so how would the plating do anything??
Maybe they don't dissipate heat as well as a bare rotor??
Painting them so they don't rust with high-heat paint doesn't seem like it would be much different, do guys powdercoat them?
Need the thermodynamic engineers to reply I guess.

 

They usually plate , or wash ,I've seen it both ways , the rotors after machining to keep the rotors from rusting . The coating is removed by your brake pads during break in , on the friction surfaces .
The rest of the rotor stays nicer looking awhile longer than bare or uncoated rotors .
It shouldn't affect the bearings , unless the races were installed before the plating , and that wouldn't be so good .