SURLY HURDY GURDY CHAIN TENSIONER

Hurdy Gurdy is a nifty device that keeps your rear wheel from slipping forward in the dropout under pedal load.
Its designed for semi-horizontal front-loading dropouts (*ahem* like those found on the Cross-Check), and will also work on many similar dropouts.
Hurdy Gurdy is investment cast of stainless steel for durability.
Its two axle holes allow for a wide variety of fore/aft wheel positions.
It will work with bolted axles, and nutted axles up to 10mm.

Hurdy Gurdy Instructions