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Surly Singleator mounts right up to your derailleur hanger and provides a simple, effective, and adjustable means of tensioning the excess chain slack found in vertical dropout single-speed drivetrains. - Triple-sealed spring, large cog capacity and chain guides - Stainless steel pivot bushing - Includes two springs for upward or downward tension adjustment - Do not use with a coaster brake, fixed gear, multi-cog or multi ring drivetrains

One of the coolest things about Surly is if they can't find an existing part that fits their standards, they just make one themselves. This cable hanger is made to fit around the oversize bolt on their Constrictor seatpost clamp so you can be sure it will fit around almost any other seatpost clamp bolt too. It comes complete with an adjusting barrel.