pacificaslim

You can use a bolt-on dropout to mount the chain tensioner or an old derailleur. This is one type, from Mr. Nemoto at cycleland.jp



Some more links:

Here's a good looking one from universal cycles: http://www.universalcycles.com/shopp...11&category=55:





And here's another one from: http://www.loosescrews.com/index.cgi...d=341815116956




You could just use a derailleur as your tensioner and here's a cheap one with built-in bolt-on dropout: http://www.loosescrews.com/index.cgi...d=341815116956