Sometimes you need a smaller cog, sometimes a bigger one; luckily, the Surly Single Cog caters to your fancy. The machined SCM415 Cro-Moly steel cog features a tall tooth profile to prevent chain skip and work with 6-9-speed 3/32in chains.

• Available in every increment from 13-22T for perfect gearing\
• Stackable and derailleur compatible for a multi-speed drivetrain
• 8- or 9-speed chain recommended but will work with 6- and 9-speed 3/32in chains
• Heat-treated for ultimate strength
• Chrome-plated for surface hardening and improved chain lubricity
• Fits Shimano-compatible freehub bodies