Surly Tuggnut Tensioner (For Horizontal Dropouts)

The Surly Tuggnut is a chain tensioner designed for bicycles with horizontal dropouts. It prevents the rear wheel from sliding forward under heavy pedaling, which can cause the chain to slip. This accessory is particularly useful for single-speed or internally geared hub setups. It is designed to fit Surly's dropouts and most other rear-facing horizontal dropouts without modification.