Chain Rubs Frame

Discussion in 'Mounting Techniques for Bicycle Motors' started by burnclouds, Jul 20, 2009.

  1. burnclouds

    burnclouds New Member

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    Hey, So my chain rubs the frame of the bike. I'm not sure what I can do to fix it. I've ridden it a little bit. The frame is slowly being ground away and the chain is too. Any suggestions?
     
  2. freewheeling frank

    freewheeling frank New Member

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    can you send a pic so we can take a look?
     
  3. Cabinfever1977

    Cabinfever1977 New Member

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    you didnt say what part of your frame.
     
  4. FileStyle

    FileStyle New Member

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    probably upper chain stay
     
  5. FileStyle

    FileStyle New Member

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    try and move rear sprocket closer to hub!
     
  6. burnclouds

    burnclouds New Member

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    Sorry I'll send a pic as soon as I can.

    The upper section of the chain is rubbing against the inside of the rear fork about 1/2 way up to where all three tubes meet.

    I have a "80cc" BGF (Left side drive)

    Also the sprocket is as far to the inside as I can get it.
     
  7. Dave31

    Dave31 Moderator
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  8. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    Whatever you do to fix it, keep the run of the chain straight. Do not resort to moving the sprocket to one side and having the chain run crooked so it clears the frame!
     
  9. burnclouds

    burnclouds New Member

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    After looking at the bike and the problem a little more, I think i am going to try some washers to spread out the frame a little bit.
     
  10. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

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    A possible solution came to me in the middle of the night...
    Is it possible to lower your engine & remount it closer to the pedals???
    You can do this by cutting a little off the rear engine mount on the back-flat side!!
    Just make sure the engine wont touch the pedaling sprocket.
     
    allen standley likes this.
  11. burnclouds

    burnclouds New Member

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    I never would have thought about that. My biggest concern with that is making sure the carb still fits. Now if I where to shorten the Front motor mount that would allow the entire motor to drop down and wouldn't effect the carb. But then what about making sure there are enough threads for the front mounting studs to hold on to?
     
  12. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

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    Drill the holes deeper & re-tap if nessesary... (^)
     
  13. burnclouds

    burnclouds New Member

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    I'm afraid that drilling deeper will cause problems. It doesn't look like there is a lot more distance before i'd run into internal components on the front.
     
  14. Cabinfever1977

    Cabinfever1977 New Member

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    maybe you should get another bike.
     
  15. burnclouds

    burnclouds New Member

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    I think I'm going to have a friend wield up some steel for me to reinforce the outside and then file out a notch in the frame.
     
  16. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

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    Dooooood... you're making this way too complicated!!
    Cut (or grind) both mounts a little bit, & see if that lowers the engine enough to solve the problem.
     
  17. burnclouds

    burnclouds New Member

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    I guess I'm not too sure about how to go about doing that and I don't want to bork anything up beyond repair. And about the best tools I think I have for this would be a hack saw or a dremmel (sp?).
     
  18. Keenan Collins

    Keenan Collins New Member

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    My chain rubs to very slightly.Do you think it be causing my engine Chain to bind when there is compression on my engine.It runs smooth with the plug out?
     
  19. allen standley

    allen standley Active Member

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