I wanted to do single speed on my Kona Stuff. I used a cog and spacers from a couple old cassettes to convert the hub. I bought an Axiom tensioner(spring loaded) because it was cheap. If I had the money, I would have bought a Rennen Rolenlager but whatever. The tensioner worked like **** at the begining because there was too much chain. I took a link out so the tensioner had barely enough room to move and bounce up to the frame. now it works perfect havent dropped a chain. Anorther problem was my derailler hanger. it was a fraction bent. Fixed that and its good now. The good thing with a spring loaded tensioner is its easy to get the wheel off and on. If you have the money, I recomend a Rennen Rolenlager. Problem free. Strong. So for me it only cost the amount of the tensioner. if you dont have old cassettes around, ask your bike shop. THey stock them sometimes for cheap. I kept a regular chain but I might change to something stronger. If you dont want anything too heavt, get a sram ss chain, if you dont mid heavy, get a bmx chain.