The race face cinch bsa30 bottom bracket to designed for frames with a bsa threaded bottom bracket the standard 6806 retainer bearings are placed on the external of the shell to allow for a 30mm spindle to make this setup stiff and reactive the cups are machined to a high tolerance to help them fit tightly to the frame and include an exclusive inner sleeve that protect against water getting in from inside your frame for cu all mountain free ride and down hill use