SRAM has made a tremendous effort to simply bottom bracket systems and standards for their crankset systems system. No one wants yet another standard, but by making a system that features one crank spindle diameter and BB cup options for most, if not all of of today's framesets, SRAM has at the least looked forward and backward in developing the Durable Unified Bottom Bracket system, or thankfully, DUB. The key to the system is a single spindle diameter that fits a traditional threaded bottom bracket shell, and is still oversized enough to add stiffness while keeping weight low for PF30 and BB30 shells. Amazingly enough, this diameter is 28.99mm. With this design and improved bearing quality, you get all the benefit and simplicity of a threaded bottom bracket option, or press-in cups, for all new SRAM DUB cranksets.

DUB is the current SRAM MTB and road crank standard, but SRAM will continue to support GXP and BB30 spindle set-ups. DUB does afford SRAM the ability to offer the system from the aforementioned 68/73mm BSC threaded shells, Italian threaded 70mm road shells, larger press fit options and even widths way out to fat, snow, and e-bike crank set-ups. In addition to bearing improvement, SRAM developed a whole new seal set-up that effectively protects the bearings from any infiltration. The threaded DUB has machined aluminum cups, while the press fit options use a steel for additional stiffness and strength for these larger shells. All in all DUB not only makes sense in simplicity, but offers tangible benefits in weight reduction when combined with DUB spindle cranksets. There will always be new standards, but SRAM is well positioned to utilize DUB in nearly every conceivable option. This model is the road bike 70mm Italian threaded version for external cup/bearing crank/bb designs.