Need crank extender

Discussion in 'Motorized Bicycle General Discussion' started by doctorscoot, Oct 14, 2010.

  1. doctorscoot

    doctorscoot New Member

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    As some of you know- I have acquired a legendary and infamous a Kamasura 250 VRX.

    The bicycle portion is a bland Chinese step-thru with a full-cover on the chain- keeping it nice and clean but a pain everytime the chain slips off the sprocket. And the bike is just plain ugly!

    SO...a transplant is in order!

    To show that I am fully and certifiably insane, I have already begun the transplant. Taking this hideous Chinese moped and removing the engine.

    And transplanting it on a US made Dyno BMX bicycle!
    [​IMG]
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    [​IMG]

    I really need to find some way to extent the crankshaft out so it won't hang-up in the engine.

    The big challenge is creating an extender from the crank to the pedal. The temptation is to just replace the really nice GT/Dyno crankset with a less substantial one. But I really like the beefy GT/Dyno set-up.


    Note how the bike is alongside one of ScooterGuy's DiBlasi R7E motorscooters. Similar in size, but way lighter! I'll probably use this as my personal MotoBike- ideal for parks, and other events where the DiBlasi is too noisy. Of course, I have no idea how well this "Mosquito" engine will work- the connecting of the various mechanical bits is a challenge. I already plan on replacing the chessy gas tank with a classier looking teardrop one.
     
  2. Dan

    Dan Staff
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    Wow, purty cool Doc. Just a thought, Could get the wide cranks just for now to get ya up and running. The cheapo wide ones are OK.

    Dunno
     
  3. curtisfox

    curtisfox Well-Known Member

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    I don't know but my thought would be to find another bike crank set. cut the arm off and have it machined to round. them the shaft cut to the right length and have it threaded or taped or weld what ever it needs to do to atach it. Just a thought
     
  4. Tim_B_172

    Tim_B_172 New Member

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    try this wide crankset. It use it on my newest build and find it to be very good and solid.

    edit:
    Almost forgot, it doesn't say so in the ad, but that set comes with an adapter to allow you to use a 3 piece crankset in a bike made for a 1 piece.
     
    #4 Tim_B_172, Oct 15, 2010
    Last edited: Oct 15, 2010
  5. doctorscoot

    doctorscoot New Member

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    I guess some measurements are in order. I'm hoping that there are some sort of "standard threads" in the crank spacing.

    Now to remember how the engine was placed on the original frame- in my enthusiasm, I forgot the placement of the rear tension roller that brings the roller into contact with the tire. Oh well....lots of fun!
     
  6. Tinsmith

    Tinsmith Member

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    Just received the wide crank set Tim B suggested. Got here in 4 days, great service!. Not sure it is going to be wide enough yet, but we shall see tomorrow. With the pedals on the shaft the ID wingspan is about 12 inches if that is any help. Good Luck, Dan
     

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