Has anyone ever used an old rear mech to tension their single speed chain? Saves spending a fortune on a chain tensioner providing you have an old rear mech knocking around (and I bet we all have garages/sheds full of bike bits) and a spare gear cable. I've road tested it and not only does it work but because my chain had a bit of slack it's made it quieter too. Before anyone's says 'why not just pull the wheel further back or remove a link' I've tried all the conventional methods, with the exception of forking out on a half link chain, and this seemed the cheapest solution. Of course the downside to this is you need a spare rear mech. I only used the top jockey wheel, by the way.