BEARINGS: ENDURO XD-15 angular contact. High-nitrogen stee alloy does not corrode or wear. Period. Grade 3 pure silicon nitride (SI3N4) ceramic balls are the best available.

This press-in bottom bracket is specifically designed for Pivot Cycles OLDER aluminum mountain bike frames (scroll through the product pictures for more information). The aluminum cups are machined to the perfect tolerance to fit the Pivot BB shells. The bearing-to-cup clearance has also been custom engineered to prevent ovalized BB shell tubes from distorting the bearings--leading to much longer bearing life than the OE bottom brackets provide. The machined aluminum center sleeve is a special narrow design that won't interfere with the extruded supports that protrude inside the Pivot aluminum BB shells.