The crank of the XX1 groupset from Sram is reminiscent of its XX counterpart at first glance: but the four-hole crank spider is adapted in the bolt circle diameter, because only one CNC-milled chainring is used on this crank, the smallest possible has 28 teeth (available chainrings are: 28, 30, 32, 34, 36, 38).

"Wide tooth, narrow tooth"
And these teeth make this crank different than anything else: thanks to narrow, but also wide teeth in combination with a longer tooth shape, the inner and outer plates of the chain should hold far better on the chainring than before. Sram calls the new design of the teeth on the chainring X-Sync technology and is so convinced of it that the chain guide can even be left at home. To get the most out of the single chainring, a special XX1 chain must be fitted, the design of which exactly mirrors the "wide tooth, narrow tooth" pattern of the chainring at the front.

10-42 cassette
While you only discover the new tooth shape on the chainring on closer inspection, the XX1 cassette is a slap in the face. Because with the 10-12-14-16-18-21-24-28-32-36-42 ratio, this cassette beats everything that has gone before in terms of range. In terms of design, this transmission miracle gets support from the XX groupset, the cassette is milled from a steel block and Sram promises good durability as a result.

A new version of the hub body is required to accommodate the smallest sprocket, the 10 mm sprocket. Of course, Sram is at the start with suitable hubs, but DT Swiss is also on board and other technology partners are in the pipeline.

The freehub on the hub is exposed to some strain with an 11-speed cassette with an 11-42 gear ratio, so Sram has devised a new lockring, and the bearings and pawls have also been adapted to withstand the high torque of the largest sprocket.

New tuning of the rear derailleur
The Sram engineers have once again reached deep into their bag of tricks with the new XX1 rear derailleur. The Type 2 function is already familiar and ensures high chain tension - but the cage now works with a wider support in a horizontal plane to the rear wheel axle. This design rides a more stable position of the derailleur across all gears. To prevent the upper guide roller from getting in the way of the 42 mm cassette sprocket, the distance from the derailleur axle to the upper guide roller has been significantly increased.

To complete the XX1 groupset, Sram is also sending matching shifters in so-called Trigger and Gripshift variants into the race.

According to the manufacturer, the new parts will be available for the first time in October 2012. The new groupset is priced slightly below the lightweight XX parts.

www.sram.com