Ritchey pro headset bearinggenuine ritchey replacement parts, the pro headset bearings are compatible with frames with fully integrated headtubes and deliver super smooth rotation for precise handling'. '.strtoupper('a')n ideal addition to your road or mountain bike mtb these hard wearing fully sealed angular contact bearings acbs will maintain their performance in all riding conditions.ritchey strives for at least twice the standard laid out by cen the european committee which determines minimum safety standards for bicycles and components sold in europe'. '.strtoupper('b')y the time you put a ritchey product on your bike, it has passed a global testing and approval process second to none.features material steel bearing type angular contact pro bearings acb for ritchey fully integrated headsets angles 45deg 45deg dimensions three separate options available, 41x30.15mm, 41.8x30.5mm and 51.9x40mm width 7mmsteerer tube compatibility separate 1.1 8 and 1.1 8 1.5 optionscontains 2 bearings for press fit and campy spec options and only 1 bearing is supplied for taper optiongenuine ritchey replacement partsmanufacturer's part numbers 41mm 200.hs247.178 41.8mm 200.hs247.173 51.9mm 200.hs247.175please note the 41mm and 41.8mm options are a pair of headset bearings, the 51.9mm 1.5 taper option is a single lower headset bearing only.buy ritchey components from chain reaction cycles, the world's largest online bike store.