SRAM launches new DUB cranks and bottom bracket

New interface designed to work with a range of BB standards

Terry McKall January 16, 2018

Seeking to simplify the crowded world of bottom bracket standards, SRAM has launched the DUB crank and bottom bracket system. The new crank and BB system is designed to work with all major existing BB frame standards, instead of introducing a new bottom bracket standard. SRAM has designed DUB to ensure it will work with whatever frame you currently have and, theoretically, whatever frame you choose to purchase in the future. The DUB system achieves this cross-standard compatibility by using a single axle diameter (28.99 mm) and four bottom bracket options for the different existing frame standards. For the acronym curious among you, DUB stands for “Durable Unified Bottom bracket,” so bonus points to SRAM for not calling it DUBB.

SRAM XX1 in podium worthy gold

SRAM also offers XX1 in a more subltle black option

On top of reducing complexity in the bottom-bracket area, moving to the DUB system has also allowed SRAM to shave weight off the company’s top-tier XX1 cranks without sacrificing stiffness. The result, SRAM says, is a crank and BB system that is one of the lightest on the market.

A wide range of BB compatibility is certainly a welcome development. The only catch being that you have to use DUB cranks with a DUB BB. SRAM claims it was only able to get cross-standard compatibility without sacrificing performance by going to a new axle diameter: 28.99 mm. While this dimension is close to the 30-mm standard, SRAM is adamant that the missing 1.01 mm is necessary to leave enough space to make a strong enough BB for all different standards. Going wider than the existing 24-mm axle standard lets SRAM shed weight without sacrificing axle stiffness on the new DUB system.

SRAM is also saying the new standard has allowed the company to improve durability across its range of DUB BBs, adding more weather seals to improve bottom bracket longevity. The new DUB press-fit bottom brackets have also moved from plastic cups to metal cups, which SRAM promises will add to the systems durability.