We'd long heard rumours of a new 11-speed mountain bike group coming from SRAM and we expected it to be an updated XX, with a wider range that more closely replicates a conventional triple. Instead, SRAM has developed a boldly progressive dedicated single-ring 11-speed group called XX1, which the company hopes will change mainstream thinking about mountain bike drivetrains.
SRAM isn't pitching XX1 as having eleven speeds – rather as a 1x drivetrain that just happens to have eleven cogs out back. The heart of the XX1 concept is its ultra-wide 10-42T cassette, which provides a generous 420-percent range. That still falls short of XX's roughly 470-percent but it's a huge improvement over current 1x10 drivetrains that many riders already run. In essence, the XX1 cassette adds a gear on either end of a current XX cassette while still retaining reasonable jumps in between.
Image above - SRAM XX (10spd)
SRAM isn't pitching XX1 as having eleven speeds – rather as a 1x drivetrain that just happens to have eleven cogs out back. The heart of the XX1 concept is its ultra-wide 10-42T cassette, which provides a generous 420-percent range. That still falls short of XX's roughly 470-percent but it's a huge improvement over current 1x10 drivetrains that many riders already run. In essence, the XX1 cassette adds a gear on either end of a current XX cassette while still retaining reasonable jumps in between.
Image above - SRAM XX (10spd)