Ritchey pro headset bearingsritchey strive for at least 2 x the standard laid out by cen the european committee which determines minimum safety standards for bicycles and components sold in europe by the time you put a ritchey product on your bike it has passed a global testing and approval process second to none features 1 angular contact pro bearings for ritchey press fit semi integrated headsets outer diameter od 41 0mm inner diameter id 30 15mm angles 45d45d material steel 454