Surly Tuggnut Chain Tensioner.

Ever stomp on the pedals just to have your rear wheel slide forward in the dropouts and throw your chain? We have....using all kinds of hubs in all kinds of frames. There are lots of BMX-style tensioners out there, but few of them fit in our dropouts without some serious grinding. So, we decided to design a chain tensioner that will keep that rear wheel static in our dropouts...and most other kinds of rear-facing horizontal dropouts. Plus, ours will open up a bottle o' brew. The body of the Tuggnut is investment cast in stainless steel for durability. It features a thumbscrew, for tool-free adjustments, and 2 axle holes for a wide range of fore/aft wheel positions. The Tuggnut comes with an aluminum adapter that reduces the axle hole from 10mm to 6mm, so you can use it with quick-release axles, in addition to nutted axles. We sell it as a single, because you really only need one...on the drive side. But, if you absolutely need one on the non-drive side of your rig, to achieve balance in your life, you are in luck...the bottle opener works either way.

For Horizontal type Surly dropouts
Incorporates Bottle Opener.
Forged Stainless Steel.
Features 2 axle holes for large range of fore and aft adjustment and includes 10/6mm adaptors to allow either nutted axles or QR skewers to function with these tensioners.
Note: Sold individually - Theres no reason why you can't buy two of these, but one is usually enough on the drive side.