by Rick Chasteen
Behold the Tuggnut chain tensioner from Surly. Although the Surly Boys market this beautiful little piece of stainless steel as a means of preventing the rear axle of a fix from sliding forward under load, I find it more useful to get the chain tensioned juuuusst right.
Installation is painless, provided you keep your fingers from between the chain and cog.Remove the wheel and the drive side axle nut and slide the Tuggnut into the axle slot with the flat of the adjuster against the end of the dropout/forkend (thanks, Sheldon). Replace the wheel in the dropout/forkend with the axle in one of the two holes in the Tuggnut, reinstall and semi-snug the axle nuts. Tension the chain with the adjuster screw and center the wheel in the triangle. Snug the axle nuts and ride.
For the nutless among us, Surly include a QR skewer adapter, the metal disk shown in the photo. Note also the bottle opener hooks. This is Good Mojo and added value typical of Surly products.
You need only one Tuggnut, but the boys would be happy to sell you a pair if symmetry is important to you.