CeramicSpeed BB86 SRAM GXP road bottom brackets are compatible only with specific pressure-adjusted bicycle frames.The diameter of the housing is 41 mm ID, and when the bearings and cups are pressed, they fit the SRAM axle and Quarq 24/22 mm.There are two versions of CeramicSpeed bearings that are installed in the cups.The first is our standard low strength and long life bearing, with hardened steel tracks and our super round CeramicSpeed Balls. Coated Bearing is our second version, which uses those same balls installed on hardened steel coated tracks for a longer life and less resistance