Any questions over whether single-ring drivetrains would continue to dominate the mountain bike market have been answered recently as SRAM and Shimano rolled out broader and innovative 1x options for the coming season.
After months of rumors and leaked photos, SRAM, which pioneered the 1x11 drivetrain four years ago, unveiled two new group sets last week built around a 12-speed rear cassette. Moving forward, the company’s top two mountain groups, dubbed Eagle XX1 and X01, will both get an additional cog out back. The new cassette is identical to SRAM’s 10-42 configuration (10-12-14-16-18-21-24-28-34-36-42), except it gets a massive, clock face–sized 50-tooth ring at the top end.
With the new, huge granny gear, the system’s gear range jumps to 500 percent. That’s greater than the range on most 2x10 setups, which should win over riders who have been ambivalent about single-ring setups’ lack of range. (Though it is still a narrower range than on Shimano’s 2x11 and 3x11 drivetrains.)
Best of all, the new cassette will work with the company’s XD driver body and doesn’t require Boost spacing in the rear hub, so anyone running the company’s 1x11 options should be able to upgrade using their existing wheels. SRAM accomplished this by moving each cog slightly closer together, which means Eagle drives take a new slightly narrower chain. The derailleur is all new, as well, though spoke and ground clearance on the units are the same as on 1x11 iterations.
SRAM is so bullish on single-ring drivetrains (remember, they’ve even launched a few 1x road groups) that they have eliminated their mountain front derailleur division. Around 80 percent of the bikes in this year’s edition of the Outside bike test were already configured without a front derailleur, and, with this news, that number is likely to keep climbing.
Shimano announced earlier this month that it, too, was upping the 1x ante with the addition of two wider 11-46 cassettes. The company jumped into 1x11 drivetrains only a year ago with the launch of XTR M9000, and though the components lived up to Shimano’s reputation for flawless engineering, it was less popular than SRAM because the cassette offered a relatively narrow range at 11-40. Shimano subsequently unveiled an 11-42 cassette in its XT level group.
The new 11-46 cassette will come in both XTR and XT level packages, and it ups Shimano’s 1x11 range to virtually the same as SRAM’s current 1x11. Of course, with the addition of Eagle, SRAM remains a step ahead in pure gear range. Shimano, however, contends that the smaller jumps between gears on its 1x11 drivetrains are more natural and easier to pedal, and it encourages riders who need a wider range to stick with two rings and a derailleur up front.
We haven’t had the opportunity to try either new configuration yet, but on the surface, we like what we see. Our biggest objection to single-ring setups to date has been with the loss of gear range, especially for mountainous riding. Both SRAM and Shimano seem to be working toward addressing this issue, and if the components work as promised, the simplicity and lighter weight of running without a front derailleur may finally win us over. Stay tuned for long-term impressions once we’ve received some test components.
Both SRAM Eagle and Shimano super-wide cassettes will be available for purchase this summer.