SRAM DUB is the single replacement for 30mm and 24mm bottom bracket spindles options. They fit all frame shell standards and DUB does NOT introduce any new frame shell standards. The new 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, 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. For better protection from the elements. For longer-lasting performance. To be stronger, smoother, simpler. Now, back to the ride. Features: One oversized spindle to work across every bottom bracket standard. Gutter Seal Technology™ drastically.