Need some input

Discussion in 'Motorized Bicycle General Discussion' started by TheMotheMan, Jun 26, 2009.

  1. TheMotheMan

    TheMotheMan Member

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    Ok guys here we go. finished my 1st build yesterday. took her out this morning, no problem. took it out just this afternoon, the chain idler pulled in when I engaged the engine (I have it as tight as I can get it on the tube) and the chain jumped to the inside of the sprocket and snapped off my master link...thank god that's all that happened. is this idler worth the risk or is it advantageous to fab one that goes between the two bars supporting the back of the bike. I just don't like the way this idler pulled into the tire like it did. I thought the chain was straight as I had no problems this morning. I am looking for thoughts of those who are more experienced than I at this. Thanks guys
     
  2. Retmachinist

    Retmachinist New Member

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    The universal bracket that the idler is on is a joke, since most chain stays will be a different diameter. Most people drill and tap a small screw through the idler bracket. Myself I have never used one of the kit idlers. I machine my own bracket and idler.

    John
     
  3. Dave31

    Dave31 Moderator
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    Most of us who run the tensioner will use a small sheet metal screw or something to keep the tensioner from twisting.

    You can run without the tensioner but I like to use mine.
     

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  4. TheMotheMan

    TheMotheMan Member

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    When I felt that chain jump, I thought the pooch had been screwed. thank god only the link busted. Is running the idler closer to the sprocket an ideal placement or in the middle somewhere? I saw on here one of the guys gave instructions how to make an idler that looked pretty good, was gonna give it a try but I lost the link to the instructions for it.
     
  5. motovation man

    motovation man New Member

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    use high temp gasket material it is suprising but when compressed between the idler and frame that tesioner will not move shaka
     
  6. TheMotheMan

    TheMotheMan Member

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    I may give that a shot. Can i get another master link for the 415 chain at TSC or will I have to go to a small engine shop?
     
  7. motovation man

    motovation man New Member

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    you can get masterlinks at napa better yet get a chain break shaka
     
  8. skyliner

    skyliner New Member

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    thats a good question and i think i may have an answer i went to ace hardware and foun a 415 master link for 2.00 i think most of your hardware shops should have them but not home depot or lowes hope i could help maybe try gasbike.net there the cheapest i know of thats where i buy all my parts good shipping also real fast they ship the next day good luck have fun
     
  9. Finfan

    Finfan New Member

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    If your local Ace doesn't have them you can always order them from most of the numerous online dealers. Dax carries them and they are good people to deal with. You can also use #41 Roller chain if you find a supplier nearby.
     
  10. TheMotheMan

    TheMotheMan Member

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    I will try Napa and ACE. the Hank across the street doesn't carry this chain, course I live in the town time forgot too. A chain breaker would be NICE. so much easier than grinding the pins off and popping with a hammer.
     
  11. xlite

    xlite New Member

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    I am of the "no tensioner" school. Mostly because I am lazy but also believe the fewer moving parts the better.
     
  12. TheMotheMan

    TheMotheMan Member

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    I would love to run w/o a tensioner, but short of moving the engine up in the frame, the chain won't be tight enough w/o one. I am going to get some 3/8" thick flat aluminum and fab one that will attach to the frame at 2 points instead of just the one spot on the frame.
     
  13. Scotchmo

    Scotchmo New Member

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    The roller acts as a tensioner and guide. Run it as close to the rear sprocket as possible, and lined up with the sprocket centerline. That will compensate for any chain misalignment and keep the chain from running off the lower edge of the sprocket.

    I prefer to keep things simple so no tensioner would be nice. But you would need to keep all slack out of the chain and alignment then becomes critical.

    Most people seem to be putting the sprocket dished out in order to gain more clearance between the tire and chain. When I measured everything, the best chain alignment was achieved by dishing in. The distance from the bike centerline out to the sprockets should be the same for the engine sprocket and rear wheel sprocket. There is just enough chain clearance for a 2.125 tire. A 1.75 tire would be better. If you need a little more clearance, it might be better to skew the front of the wheel slightly to the right. Just not so much that it interferes with the pedal side chain.
     
  14. TheMotheMan

    TheMotheMan Member

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    See now there becomes another problem. Mine is a Dax kit, and there is no dishing of the sprocket. it is a 41T sprocket. I am gonna run to TSC and get some of the materials to make a tensioner I saw on the site here. IT looked pretty solid compared to this POS that I have now.
     
  15. Cabinfever1977

    Cabinfever1977 New Member

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    i went to walmart:
    bought a 410 chain with master link for $7 and a chain breaker with master link for $5.

    if you cant dish the sprocket,you can use spacers.
     
    #15 Cabinfever1977, Jun 27, 2009
    Last edited: Jun 27, 2009
  16. TheMotheMan

    TheMotheMan Member

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    Not all Walmarts are created equal. The ones here only carry small bike chains. I had to go to 3 different ones to find a suitable seat. I ordered 2 more links from SBP for the 415 chain I have. Not happy about having to wait but I gotta do what I gotta do. This will give me time to get my tensioner made.
     

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