Rethinking the validity of your singlespeed bike purchase? Wishing youd gone the geared route after all? Dont worry, weve been there too. Problem Solvers is here to help! Our Chain Tensioner with Derailleur Hanger is about options. Keep a multi-gear wheel, derailleur, and shifter around for a relatively easy switch between one-and-done simplicity and easy-on-the-knees bliss. This little guy essentially doubles your bike fleet!