Wolf Tooth BSA Bottom Brackets are engineered to be smooth, durable, lightweight, fast, and user-serviceable. Wolf Tooth's ground-up design features custom bearings, seals, bushings, and cups, which eliminate creaking and balance best-in-class weather sealing with optimized bearing radial compression, alignment, and preload for low drag. They're available for 24mm Shimano, 29mm DUB, and 30mm spindle diameters for maximum compatibility, and four colors to match your other Wolf Tooth Color Shop components. The bearings in Wolf Tooth Bottom Brackets feature a custom design. The balls and race are made from a hardened chrome bearing steel. This has a higher surface hardness than stainless, which improves the durability of bearing races and reduces spinning resistance and noise. An ACOSUR ZNA c