Wolf Tooth MK0 BSA Bottom Bracket - For SRAMCeramic speed. Zero compromise on durability. The Wolf Tooth MK0 BSA Bottom Bracket brings ceramic bearing performance to BSA threaded shells without the durability concerns that have long followed ceramic BBs. Custom ceramic bearings built to Wolf Tooth's exacting specifications pair with best-in-class weather sealing - a combination the industry rarely gets right. Custom polymer spindle bushings eliminate metal-on-metal contact between the bearing inner race and crank spindle, the most common source of BB creak. An adjustable-width sleeve fits 68mm and 73mm BSA shells with the same BB (with 83mm and 100mm sleeves available separately) Designed, machined, and assembled at Wolf Tooth HQ in Minnesota. Fully user-serviceable, with replacement parts available. Features Custom ceramic bearings built to Wolf Tooth's specifications with low-drag seals, delivering reduced friction without sacrificing the weather resistance that makes them last Best-in-class weather sealing protects the bearings from water, mud, and debris for reliable performance in harsh and inclement conditions Custom polymer spindle bushings eliminate metal-on-metal contact between the bearing inner race and crank spindle, removing the primary cause of bottom bracket creak Adjustable-width sleeve fits 68mm and 73mm BSA bottom bracket shells with a single BB; 83mm and 100mm sleeves available separately Installs with standard 46-12 spline tools - no proprietary tooling required100% user-serviceable with replacement bearings, bushings, and o-rings available, and full service guides provided Designed, machined, and assembled at Wolf Tooth HQ in Minnesota, USASPECIFICATIONSSpindle Compatibility SRAM DUB (29mm)Shell Compatibility BSA threaded, 68mm and 73mm (included sleeve); 83mm and 100mm (sleeve sold separately)Bearing Type Ceramic (Silicon Nitride balls, AISI 52100 chrome steel race with ACOSUR-ZNA corrosion-resistant coating)Cup Material6061-T6 aluminum Shell Material POMSpindle Bushing Material POMSeal Materials NBR, Urethane Weight82g (without spacers)Installation Tool Standard 46-12 spline Includes2x 2. 5mm shell spacers; 2x 0. 5mm, 2x 1mm, 3mm, 5mm, 7. 5mm spindle spacers Made In Minnesota, USA | Wolf Tooth Components | Mk0 Bsa Bottom Bracket - For Sram | Shadow Gray | 29Mm