Agree with RR. I've had 10, 11, 12 mm's..broke them all except the original 10 mm bar. Thought the hardening process was cured but I guess not. Doesn't matter, I filled the progressive springs with made up rubber wedges and the handling was excellent, so went back to the softer bar. No ski lift. Also, front preload soft..maybe 7 threads showing above. Front suspension spring shimmed and set soft too..this on an RX, not a warrior.