before i make a mistake

Discussion in 'Motorized Bicycle General Discussion' started by kyl 46&2, Jun 2, 2010.

  1. kyl 46&2

    kyl 46&2 New Member

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    after tearing my build down and taking thorough inspection i've noticed that the mount for my down tube has a huge gap to it. like 7-8mm kinda gap. after reading numerous posts on how important it is to have a good flush mount i can safely blame this problem for breaking my ''stupid threaded rods''. now my question is can i fill the gap to create a nice flush mount and what kind of material will work well. i have some JBweld and a dremmel tool and was thinking about filling the mount then shaping to a proper fit but being the front mount i don't want to ruin anything. so before i make a mistake what do you all think.
     
  2. Mind_Reader7

    Mind_Reader7 New Member

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    Can you take a pic? I'm not sure what you mean.
     
  3. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

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    If you mean that the diameter of the down tube is smaller than the inside of the front mount? You can make a shim out of 1/8" steel to wrap around the down tube to make the engine & frame fit snug! ;)
     
    #3 Venice Motor Bikes, Jun 2, 2010
    Last edited: Jun 2, 2010
  4. Mac

    Mac New Member

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    It is also important to make sure the engine is "in the saddle" without the front or rear mount bolts being tight, ensure the engine is "Flush" to the frame both front and rear. Then tighten as needed. As Mind Reader stated, a picture would be helpful.

    Mac
     
  5. taddthewadd

    taddthewadd New Member

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    I think I get what you are talking about. If you vision the surface of the engine mount that actually touches the down tube there is some metal missing. Is this what you mean? If so I would think that if the perimeter of the engine mount has metal touching the down tube it is ok even if some of the middle is missing.
     
  6. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    I use PC-7 (epoxy putty) to fill that kind of gap. Wrap the tube with saran wrap, then mix the putty, mount the engine, but don't fully tighten it, just get it snug enough that the putty starts to squeeze out. Let it harden, then tighten the rest of the way.
     
  7. kyl 46&2

    kyl 46&2 New Member

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    i've used epoxy glues before. is the the putty already mixed and does it hold well to the engine mount. i don't anything slipping out of place. i 've got a pic ready. just trying to upload it. my computer service as been crappy for the last few days.
     
  8. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    It's a putty that you knead together after you take some from each of two containers....similar to JB Weld, but much thicker. I have done it twice before.
     
  9. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    You can also thicken epoxy with flox, a milled cotton fiber.
     
  10. kyl 46&2

    kyl 46&2 New Member

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    i hope that worked
     
  11. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    Yes, a lovely abstract of black, grey and a blue-ish.
     
  12. kyl 46&2

    kyl 46&2 New Member

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    yeah sorry about the poor quality. doesn't help that the engine and the bike are black. i picked up some ''J-B stick'' should work. i hope.
     
  13. corgi1

    corgi1 New Member

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    a gap between the two crankcase half's,,,or gap from frame to the motor mount,as in 1 1/2 inch mount circle and 1 inch frame
     
  14. kyl 46&2

    kyl 46&2 New Member

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    it was a gap between the bike frame (down tube) and the front motor mount. the down tube measured 1 1/2'' w the motor mount is a larger than normal so i ended up with a little extra space all around. i went with bikeguyjoe's idea and used the epoxy putty witch up to this point as worked beautifully. it feels and looks really solid now. i'm waiting on some parts before i fire it back up. till then i'll work on the little things like air tight seals and such. gotta put it down for awhile though my girl is starting to get angry at me for spending to much time on my bikes than in the house with her.
     

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