The Surly Hurdy Gurdy is a stainless-steel chain tensioner designed to prevent rear wheel slippage in semi-horizontal, forward-facing dropouts, like those on the Surly Cross-Check. Its construction provides long-term durability, while dual axle holes allow for a wide range of fore/aft wheel adjustment. Compatible with standard quick-release skewers, bolted axles, and nutted axles up to 10mm.