“One ring to rule them all” – the theme of Lord of the Rings now also applies to SRAM cranksets, as the component giant introduces a new system of cranks and bottom brackets. The new DUB system is said to be lightweight, durable and simple – we walk you through the details.

So far, SRAM cranks were available with both 24 mm and 30 mm spindles, depending on the bottom bracket standard. With the new DUB system, there is only one crank that fits with all current bottom bracket sizes. The “one ring” comes in the form of a spacer that allows riders to adapt the crankset to the four new bottom brackets, covering all common frames. The new spindles measure 28.99 mm and are therefore not compatible with previous bottom brackets.

DUB stands for “Unified Durable Bottom bracket”, all screaming simplicity and longevity. SRAM provides the rationale for the new spindle size in the following video, the new measure is supposed to strike the best balance of bearing size, durability and weight.

The spindle is constructed as one piece with the non-drive side crank arm, therefore, the spindle can remain in the frame when swapping chainrings. DUB cranksets use a variety of Direct-mount chainrings, all of which are compatible with each other. There are still two different offsets for Boost and non-Boost chain lines though.

DUB Cranks

SRAM introduces a wide range of new DUB cranks, replacing the current Eagle offerings. The top-of-the-line model comes in form of the XX1 Eagle DUB cranks, that weigh in at feathery 422 g (175 mm incl. 32t chainring) and are fully optimized for XC use. The weight has been realized with a lighter spindle and new SL chainrings. The X01 Eagle DUB crank is slightly heavier and sturdier, aimed at trail and enduro pilots, while the GX Eagle DUB offers a budget-friendly entry option. There are also four Truvativ DUB cranks that cover additional price points.

SRAM Cranks

XX1 Eagle DUB X01 Eagle DUB GX Eagle DUB
Material carbon carbon aluminum
Weight* 422 g 471 g 621 g
Length 170, 175 170, 175 165, 170, 175
Chainring aluminum CNC (SL) aluminum CNC aluminum forged
Price € 570 – € 585 € 540 – € 550 € 150 – € 205
Availability March 2018 February 2018 February 2018

*(175 mm inc. 32t chainring)

Truvativ Cranks

Descendant Carbon DUB Descendant 6K DUB STYLO Carbon DUB STYLO 6K DUB
Material carbon aluminum carbon aluminum
Weight* 555 g 717 g 555 g 705 g
Length 170, 175 170, 175 170, 175 170, 175
Chainring aluminum forged steel aluminum forged steel
Price € 290 € € 115 € € 290 – € 345 € 115
Availability February 2018 May 2018 February 2018 May 2018

*(175 mm incl. 32t chainring)

DUB Bottom Brackets

The new bottom brackets feature additional seals and should thus be better equipped against environmental influences. The press-fit bearing cups are now made of steel rather than plastic. The DUB BSA bottom bracket is mounted with the same tool as Race Face BSA30 or ZIPP BBs, for example, the Park Tool BBT-79.

DUB BSA DUB PressFit DUB BB30 DUB PressFit 30
BB Frame 
Interface BSA
(100 mm, 73 mm)
(121 mm, 89/92 mm)
BB30 PF30
Weight* 76 g 71 g (92 mm) 82 g 89 g
Cup Material aluminum aluminum steel aluminum

First Impression

The introduction of the DUB-system is comparable to the presentation of the new MacBook lineup, that relies solely on USB-C ports. The lack of backward compatibility will generate a lot of discussions, but ultimately DUB does offer some considerable advantages. Riders with more than one bike in their shed will be able to swap their SRAM cranks regardless of the BB standard. Bike shops will have to add an additional size to their stock for the next years, as the existing 24 mm and 30 mm offerings will still be available as spare parts. But once DUB is widely used, it has the potential to simplify the chaos around current bottom bracket standards with a single crankset. In model year 2019 we will see many stock bikes with the DUB cranks, so the system should spread fairly quickly. Whether the new bottom brackets are really more durable remains to be seen in practice, we are excited to find out.

More Information on sram.com

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