The race face cinch bb92 bottom bracket is designed to allow you to use a 30mm spindle with a shimano press fit shell without a decreasing the ball bearing size the custom made 19 ball flanged retainer bearing have fully coated races and are factory filled with phil wood grease for improved corrosion resistance and long life the are all sealing in with an inner sleeve that is exclusive to race face and protect against water getting in from inside your frame for xc all mountain free ride and