CeramicSpeed Bottom Bracket - BB86 - GXP SpindleBB86 for SRAM GXP The CeramicSpeed BB86 SRAM GXP Road Bottom Brackets are compatible with press fit specific bike frames only. The shell diameter is 41mm ID, and when the bearings and cups are pressed in, they fit the 24 22mm SRAM and Quarq spindle. There are two versions of the CeramicSpeed Bearings that come installed in the cups. The first is our low drag, long life Standard Bearing, with hardened steel races and our super round CeramicSpeed Balls.