SRAM this week released details of its second 1x11 mountain bike group, called XO1. The group slots in a few hundred dollars cheaper than its first 11-speed, single-chainring group, XX1, and will be available in September.
The groups are very similar, with a few carbon parts on the XX1 group replaced with aluminum. The most unusual piece of the group — the 11-speed 10- to 42-tooth cassette — is made with the same machining process for both groups. The XO1 cassette has a different finish, however. The XO1 cassette still has a sobering MSRP of $399.
The new group has a 94-millimeter chainring bolt pattern, instead of the unique 76-millimeter bolt circle on the XX1 group. The change means the smallest chainring available on the new group is 30-tooth, instead of the 28-tooth ring available for XX1. The XO1 group has carbon crankarms, but aluminum arms apparently are available for OE, as several bikes BRAIN has seen at product introductions recently had them.
SRAM is also making its X-Sync chainrings available in the popular 104-millimeter crank bolt pattern, for riders looking to use the 1x11 system with other companies' cranks. SRAM also recently announced it is willing to license the design to aftermarket chainring makers.
Like XX1, the new group will be available with a trigger shifter or a twist shifter. The twist shifter has steel indexing ramps for positive action and durability, rather than the plastic indexing of less-expensive twist shifters.
XO1 MSRPs: Cassette: $399 Chain: $63 Crank (no ring): $279-$319. Available in 170 or 175, for GXP or BB30, in black or red. GXP bottom bracket: $42 Trigger shifter: $139, black or red GripShift with locking grips: $129 Rear derailleur: $269 Chainrings: $98 to $127, in 30, 32, 34, 36, and 38 tooth in 94 mm BCD. 32, 34, 36 and 38 tooth available in 104-millimeter BCD.
