Check the listing for details. Wolf Tooth Purple BSA Bottom Bracket - Durable Sealed English (BSA) for 68/73mm. Color: Purple, Condition: New. Listed at 129.95 USD. Wolf 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 has been hardened for improved durability and reduced friction with ZNA corrosion-resistant coating, while the ball diameter, width, and counts were custom selected by Wolf Tooth for top quality based on spindle diameter. Wolf Tooth bottom brackets are machined at Wolf Tooth in Minnesota, USA.Best-in-class sealing protects bearings from water.