Micargi Frame Failure

Discussion in 'Motorized Bicycle General Discussion' started by jowens, Apr 5, 2012.

  1. jowens

    jowens New Member

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    Lately I have seen a few post detailing how these frames are prone to breaking. Nevermind I have one of these frames and those posts got me scratching my head in worry. Anyhow I have done a tear down of my bike and see how these frames could fail! Its not because the frame is weak or anything else, its because if you use the kit supplied frame mount options they dont work so well and allow the engine to torque and rub against the frame. My suggestion to combat this is to buy a quality frame mount option. After my tear down I noticed how the front mount bolt from the plate and U-Bolt method had dug into my frame. This also showed me that the frame is of good thickness and put my worry to rest about strength. Of course I had to mend the dug out portion of my frame that was certain to fail if not attended to. When I touched my MIG welder to the spot needing the repair, I burnt through the remaining steel. Not to worry though, I just simply filled the hole and its probably stronger now. Thank goodness Ive had a little practice here lately with my welder. Heres some pics.
     

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  2. jowens

    jowens New Member

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    Oh yeah I forgot to mention the reason for my tear down......Im building a 99cc Predator onto my bike and about to weld a good solid mounting plate to the frame made of 1/4" steel......so I dont see this ever being a problem again
     
  3. 2door

    2door Moderator
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    There have been reports of the frames cracking at other points other than the engine mounts. Keep a close eye on the head tube especially, and around the bottom bracket.

    Tom
     
  4. happyvalley

    happyvalley New Member

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    The real culprit is simply modern bicycle frames are built with drawn tubing that was never specced to have engines clamped to it vs straight wall pipe that motorcycle manufacturers used. The larger the engine the more under-specced it is and why motor assisted bicycles are most appropriately utilized with small, low power, lightweight, helper engines. Just try to get a bicycle manufacturer to honor a bicycle warranty or cover liability after learning you clamped an engine on their product.
     
    #4 happyvalley, Apr 5, 2012
    Last edited: Apr 5, 2012
  5. jowens

    jowens New Member

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    Thanks 2Door.....I will definately keep an eye on those 2 welds......they look pretty good now tho....but I am putting a little more to it after this build!
     
  6. rustycase

    rustycase Gutter Rider

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    Tnx for the post!

    I had planned to make provisions to avoid that as I constructed my front mount.
    Unfortunately it will make it a bit uglier, but I can live with that, i suppose.
    Best
    rc
     

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