Chain Tensioner Chain tensioner

Discussion in 'Transmission / Drivetrain' started by jototojo, May 16, 2011.

  1. jototojo

    jototojo New Member

    Hi people,
    From argentina again, hahaha.
    The other day i was ridding on my recently build 2 stroke bike when i hear a "clack" sound, and i see that the plastic part of the tensioner that turns around and guides the chain like moves from right and left, only the plastic part, the metal part is welded to the bicycle.
    So this makes the chain go to the centre part of the wheel and finally it goes off the sprocket.
    Guyyyss, WHAT CAN I DO!!???
    HELP pleassse.
    Thanks again.
     

  2. Oddzball

    Oddzball Member

    You can buy chain tensioners all over the place. Chop the old one off with a hacksaw and get a new one, or replace the pulley on the old one.
     
    Last edited: May 16, 2011
  3. jototojo

    jototojo New Member

    Yes but i live in argentina and its not really easy to get a new one, so im looking for a fix.
     
  4. Oddzball

    Oddzball Member

    You can make one really easy.

    You need a small pulley, a flat 1 inch strip of metal and a back to that strip of metal that looks like a clamp so you can put it on your frame.

    Then its all about drilling a hole at the top to mount the pulley in and bending the lower part to clamp it to the frame.

    If you tensioner is made of metal it will probably have a longer life span as well, just make sure it has bearings and is well oiled.
     
  5. jototojo

    jototojo New Member

    Yeah, ill try that tomorrow and see what happens.
    Thanks for your helpp!!!!!!
     
  6. jototojo

    jototojo New Member

    Hello people again, i still cant fix this problem, i think im gonna cut the part i welded so i can move the chain tensioner far from the wheel, what do you think???
    Thanks.
     
  7. V 35

    V 35 Member

    I saw an ' article ' on tensioners that suggested the tensioner be about 1/3 of the way from the rear sprocket. I personally agree with that theroy. Sportsman has the best setup I've seen to date. Simple, safe, tough. Whatever style you run, check it before every ride. I forgot to, and got bit when the bolt loosened, and the roller hit the spokes.
     
  8. motorpsycho

    motorpsycho Active Member

    The stock chain tensioners are marginal at best...they aren't very good at all.
    You can buy an aftermarket one which can be expensive.
    You can buy another stock one that will also fail.
    OR,you can make one out of a 10 speed derailer if you're good.
    look up downhill bike chain tensioner on e-bay and you will find what looks like a single derailer, with a steel cog in it.
    these are used to convert multi-speed mountain bikes to single speeds.
    You can easily make a chain tensioner out of one of these.
    I made one and it took me about 30 minutes to modify it to work.
    Plus, they are CHEAP.
     
  9. V 35

    V 35 Member

    The deraileur can be converted by using a spacer [ piece of steel fuel line ] and longer bolts. Remove top jockey wheel, for use as spare. The deraileur spring is plenty stiff
     
  10. motorpsycho

    motorpsycho Active Member

    yes, but you will need to find one that has a steel cog on it. Most derailers have plastic cogs and they will not last.
     
  11. motorpsycho

    motorpsycho Active Member

    here's the one i used, and this is what it looked like when i got it.
    [​IMG]

    http://www.ebay.com/itm/DH-DOWNHILL...Cycling_Parts_Accessories&hash=item45fcf14fe0

    here's how i modified it to work.
    [​IMG]

    a lot of people say that it's better to have the tensioner on the bottom of the chain, but i've found that it works the same weather it's mounted on the top or the bottom, front or back. as long as it puts constant tension on the chain, it will work.

    there's a similar one on e-bay but it's a little more expensive and it has a plastic cog.
    http://www.ebay.com/itm/New-Bike-Al...Cycling_Parts_Accessories&hash=item5643a511a5

    I made the one for my o.c.c. chopper out of a peice of delrin plastic. all it is, is a wedge that the chain slides across, which puts constant tension on it. I took this idea from dirtbikes because some of them use a delrin type slider on the swingarm to keep the chain from rubbing of it gets too loose. I drilled a hole in the center of it and filled it with grease, so it automatically adds grease to the chain as it wears down. plus, i have it hidden on the inside of the frame.
    It's easy to make a tensioner, you just have to figure out what will fit your bike best, and what will be the easiest for you to work with.
    it's been on my bike for 2 years now and it has very little wear.
    [​IMG]
    [​IMG]
     
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