The Surly 1x1 Singleator offers a reliable, adjustable solution for tensioning chains on singlespeed drivetrains with vertical dropouts. Designed to mount directly to a standard derailleur hanger, the Singleator features a triple-sealed spring, floating 11-tooth pulley, and fully adjustable chain line. Its forged body and stainless-steel pivot bushing ensure long-term durability, while chain guides and a wide cog capacity support consistent, quiet operation. Compatible with both 1/8" and 3/32" chains.