Surly Single Cassette Cog 3/32" Splined 13t MFPN=910-21-372 } Works with all multi-speed

} Works with all multi-speed bikes (including 12-speed) as well as some single-speed models and e-bikes

The Shimano 105 FD-R7100 series of 12-speed front derailleurs feature light front shifting smooth and natural shift action and Shimano toggle link construction with an optimized cage design that is seamlessly compatible with disc brake road bikes

Bad conditions won’t stop you from getting a ride in and the Rock Hawk tire is right there with you

EVOL air spring with enlarged negative air spring to assist with mid-stroke support

all electrically cured to minimize rolling resistance

Surly Single Cassette Cog 3/32" Splined 13t MFPN=910-21-372 } Works with all multi-speedSurly Single Speed Cogs. Designed as a singlespeed cog but may also be stacked and used with 9 speed shifter. Multi gear use will result in slower less crisp shifting than cogs designed for multi gear systems Fit Shimano freehub splines SCM 415 hardened chromoly steel Photo for color and material reference only Tooth Count 13 Cassette Body Type Shimano HG 7 Speed Drivetrain Speeds Single Speed 3 32" Material Steel