Wolf Tooth Bottom Bracket - English (BSA), 68/73mm, For 30mm Spindle, Raw SilverWolf Tooth English (BSA) bottom brackets are engineered to be durable, reliable, lightweight, and smooth. The weather sealing is best in class, with o ring seals on the spindle and inner shell, a wiper connection seal between the bearing and end cap, bearing race seals, and a labyrinth end cap design. To prevent creaking, spindle bushings separate the bearing inner race and crank spindle to eliminate metal on metal contact. The custom chrome bearings