Enduro Bearings XD-15 Ceramic Bottom Bracket Bearing Kit - 24mm / BB90 (BKC-54109

Ceramic ball bearing with 3/1,000,000" concentricity. Oversize balls and silicone seals for low rolling resistance. Features of the Enduro Bearings XD-15 ceramic ball bearings 15% enlarged high-precision balls within 3/1,000,000″ concentricity Highly polished raceways Particularly low-friction silicone seals Further reduced friction and extended durability Assembly instructions: When mounting, ensure that the axial pressure remains low. With this type of bearing, the crank axle is only distanced, no axial preload! As with Shimano cranks, for example. When using a shaft washer for axial preload, angular contact / angular contact ball bearings, e.g. frequently used by SRAM/GPX, must be used.