SURLY Singleator Chain Tensioner – Black

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

Source: Quality Bicycle Products