The SRAM DUB bottom bracket series has a simple job—connect your crankarms and protect the smooth, long-lasting application of power to your drivetrain. To allow that singular focus, SRAM has engineered the DUB™ spindle to be the one true unifying component. One oversized spindle to work across every bottom bracket specification. For better crankarm compatibility. For better protection from the elements. For longer-lasting performance. To be stronger, smoother, and simpler. One oversized spindle to work across every bottom bracket specification Sealed cartridge bearings available in both stainless and ceramic versions Details: Model: BB-DUB-BB30-A1 Spindle Interface Type: SRAM DUB Bottom Bracket Shell I.D.: 42 BB/Frame Interface: BB30 Bearings: Ceramic or Stainless Steel Compatibility: The SRAM DUB BB30 bottom bracket is compatible with the following: Crankset: SRAM DUB Cranksets Frame Interfaces: 68mm (Road Wide) 68/73mm (MTB) 73mm (MTB Wide, 55mm chainline) 73mm (Road) 73mm (Road Wide) 83mm Cannondale Ai (MTB) 83mm Cannondale Ai (Road)