Upgrade your stock bottom bracket. Enduro bottom brackets are designed to spin more efficiently and for longer.ÊProven time and again in World Cup race conditions, the ZERO Ceramic bearings are the ultimate race day weapon. Oversized Grade 3 balls roll on races which are ground to a mirror finish after receiving Magnetite and then Cryogenic treatments for hardness and longevity. More durable and with even lower rolling resistance than any 2RS bearings, they come closer to that magic ÒzeroÓ rolling resistance number. ÊEnduro Bearings uses Silicone seals which are more slippery than rubber seals used by other ceramic bearing suppliers.Fits BB86 frames - 41mm diameter with a shell width from 86.5mmLightweight, durable Delrin cupsZero CeramicÊBearingsIncludes BB30 adaptors to fit 22mm chainset60.84g