PaulMelvin Chain Tensioner, Single Speed, 2 Sp, 100g

works well

Perfect for multi speed to single speed bike conversion also will handle up to a 20 tooth difference on front crank if you desire to build a "twingle" speed i.e. twin speed. I built the twin speed, with Shimano 411 shifter / derailleur, perfect set up, 50 tooth gear for riding / training and 32 tooth "second speed" for "rescue" i.e. legs burned out need to get home, or oh no, another hill. would recommend this to anyone easy plain simple set up