Chain Tensioner Derailleur as a chain tensioner

Discussion in 'Transmission / Drivetrain' started by Commoditism, Feb 26, 2012.

  1. Commoditism

    Commoditism New Member

    Has anyone made a chain tensioner out of a typical geared bike derailleur? It seems like it would be pretty fun/cool and work better than the standard one..

  2. perilous

    perilous Member

    If its on the right hand side it will work fine, putting one on the left is a bit of a pain I have done it but you have to reverse - flip the spring.

    Also geared bike chain is often narrower than non geared bike chain (eg BMX chain) so you may need to add some washers to spread the chain guide a tiny bit so the chain wont rub.

    To answer your question it does work fine :)
  3. Commoditism

    Commoditism New Member

    Thanks! I was also wondering, would you have to put it on the inside or outside of the frame, and how do you get it to not touch the rear sprocket?
  4. perilous

    perilous Member

    When I did it I mounted it on the out side of the frame, however I had a regular bmx freewheel welded to the hub on that bike as I reversed the pedal chain. I would assume your going to need fabricate a custom bracket to bolt it to on your bike to get it low enough. In my current build I have made my own spring loaded chain tensioner however it started life as a derailer, I plan to update my build thread later tonight if you want to check it out.