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.. DUB is the single replacement for 3mm and 24mm BB spindles options. DUB bottom brackets fit all frame shell standards. DUB does NOT introduce any new frame shell standards.For PressFit frames. -. -. -. Colour-Black. Sizing - 73 mm