Chain Tensioner thoughts on chain tensioner

Discussion in 'Transmission / Drivetrain' started by suitcasejefferson, Dec 11, 2011.

  1. I have yet to build one, but I can already see that the biggest weak point of the Chinese engine kits is the cheap cheesy chain tensioner. I have found companies selling prebuilt motorized bikes for over $2000 that still have these things. There has got to be a way to eliminate them once and for all.

    I also ride motorcycles, including dirt bikes, and they have polyurethane rubbing blocks on top of the swing arm for the chain to rub on. The chain does wear groves in this stuff, but only to a point. It is the side plates that cut the grooves, once the rollers come into contact with it, the wear stops. I have a chain "roller" from a dirt bike, about the size of a skate board wheel, which is designed to be in constant contact with a moving chain. Now, using skateboard wheels is not exactly new, but it still leaves the biggest part of the problem, the cheesy bracket that will either bend or turn on the frame.

    I have been wondering about welding a piece of fairly heavy steel between the seat stay and chain stay, in about the right place to mount a tensioner, then using the roller I have, with a large washer behind it that is larger in diameter than the roller, making it impossible for the chain to come off the roller. and the welded steel plate would be way to strong for a chain to bend it. Anyone ever tried something like this?

  2. 5-7HEAVEN

    5-7HEAVEN Member

    Several people have tried and posted pictures here.

    You are correct. IMO, the stock chain tensioner is a fall-down accident waiting to happen. Like you stated, a simple strap from chain stay to seat stay would easily cure that issue.

    If you research, you'll find many ways that others have solved the problem. Although I have a different style engine drive, I also fabbed a skateboard wheel tensioner for my chain. It's cheap and simple to make.
  3. Cavi Mike

    Cavi Mike Member

    If it really concerns you, put the tensioner on your pedals side and use the wheel to tension the engine chain. Problem solved.


    I just don't see the problem. I lurked here for a long time before joining/building a bike and almost didn't because of all the horror stories. I use the stock tensioner on all my bikes. I don't recommend drilling holes anywhere in a frame but once set I have pinned all mine so they can't rotate into the wheel.
    Next was the cheap looking plastic wheel. Had skateboard wheels ready to go when needed.....over 1000 miles on two of my bikes and haven't needed to replace one yet!