The SRAM DUB BB30 bottom bracket series has a simple jobconnect your crankarms and protect the smooth, long-lasting application of power to your drivetrain. To allow that singular focus, we’ve engineered the DUB spindle to be the one true unifying component. One oversized spindle to work across every bottom bracket standard. For better crankarm compatibility. SPECIFICATIONS: BB-frame interface: BB30 Crank-BB interface: DUB Bearing type: Standard Spindle diameter: DUB Cup material: Aluminium For better protection from the elements. For longer-lasting performance. To be stronger, smoother, simpler.