Chain Tensioners

Discussion in 'Motorized Bicycle General Discussion' started by gphil, May 7, 2011.

  1. gphil

    gphil Member

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    I see a lot about these little guys. I was thinking that a derailer on a bike with gears has a spring loaded tensioner that moves up and down keeping tension on the chain that has to move over the freewheel. Why couldn't one of those be used for a tensioner. It would keep the chain taught and in place because it has a covered area the chain has to go through. I put on on a recumbent midway on the frame to keep tension and it works great. No chain flop and moves with the changing of the gears etc. Get one with enough strength or tighten it and I think it would work great. They have ability for side movement also. just a thought, may not work on engine power. I may try it.
     
  2. chainmaker

    chainmaker New Member

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    Best bet if you need a tensioner. Get the motor side good , and use the tensioner on the pedal side
     
  3. gphil

    gphil Member

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    Agree but it seems like I read a lot of reports of the tensioner getting off on the motor side and having to add and take away links etc. I was just thinking if it is correct to start a spring tensioner would make up the difference in chain stretch from use and keep it on the sprocket better. Just having brain explosions I guess.
     
  4. DuctTapedGoat

    DuctTapedGoat Active Member

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    You can run springed, but each bike is going to have a different alignment, which is the other purpose of the tensioner. You lose some of that aspect when you go springed.

    I saw a simple springed not too long ago - simple enough, just added the tensioner on a lever bar attached to the stock tensioner with a carriage bolt, and the other side of the lever was p-taped to the chainstay and held to the lever via a spring. Looks like 5 bucks in materials and less than 10 minutes of work.
     
  5. wileydavis

    wileydavis New Member

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    I like to go on long rides, 100-200 miles per day and I hate having to stop and adjust my chain tension. For that reason I love spring-loaded tensioners. However, my setup uses a centrifugal clutch. For bikes that have a manual clutch (and can thus engine-brake) when the load on the chain gets reversed as during engine-braking, the bottom side of the chain will be under tension and the top side will go slack. because there's no tensioner to take up slack on the top, you can risk throwing a chain when engine braking.

    Here's a pic of one I just made for use on a Staton gearbox driving a freewheel crank:

    [​IMG]
     
  6. gphil

    gphil Member

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    The ones I used were salvaged from hacked bikes and were nearly new. Made some small brackets from pieces of steel , couple tacks with welder and was complete. On one, had to put it upside down and position it so it would follow the chain. Yours appears to be much heaver duty than mine but then I was not engine driven. fun stuff huh.
     

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