SRAM DUB English Bottom Bracket - English/BSA, 68/73mm, MTB Boost 55mm CL, Black Designed for use with SRAM Boost cranksets with 55mm chainlines Gutter Seal Technologyâ„¢ drastically improves sealing against the elements Sealed cartridge bearings One oversized spindle to work across every bottom bracket standard Spindle Interface Type: SRAM DUB BB Shell Width (mm): 68 , 73 Bottom Bracket Shell I.D.: 1.