Originally Posted by monkeyracing

They're just plain stronger. We used to have people burning through gears like mad, but since the black ones became available there's less wrenching and more racing.

Originally Posted by GreazyFinger

ive just installed the black gear set into an m03 , no speed difference , noise about normal but quieter than what it was before i changed out the stuffed pinion , with any luck they will simply last longer as they are supposedly reinforced..ive only used two of the gears as im running a ball diff so the gear diff part wasnt required