Check the listing for details. Wolf Tooth T47 External Bottom Bracket for DUB - Ultraviolet Purple,. Color: Purple, Condition: New. Listed at 139.95 USD. Wolf Tooth T47 External Bottom Brackets are engineered to be smooth, durable, lightweight, fast, and user-serviceable. Our 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 , 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.