Will this work?

Discussion in 'General Questions' started by bjaspud, Feb 23, 2009.

  1. bjaspud

    bjaspud New Member


    A couple of years ago I fabricated an electric go kart from scratch for my daughter using electric scooter technology. http://www.youtube.com/watch?v=89QZF559pbE It worked quite well. Top speed was 13mph using a 500W motor, 11 tooth primary drive sprocket and an 80 tooth wheel sprocket.

    I am now working on plans for an electric bike using the same technology. Here is my plan. Please tell me if you think it will work.

    Motor = 500W, 2500 RPM, Scooter controller and sla batteries. Single speed bike with coaster brake. Motor has 11 tooth sprocket. It will be mounted to with the sprocket on the right driving a 5/8" jackshaft with a 25 tooth sprocket on the right. On the other end of the jackshaft (left side) will be a left handed freewheel with an 18 tooth sprocket. It will drive a chain to a traditional 44 tooth or 36 tooth left side drive / spoke mounted (rag mount?) sprocket. The freewheel should allow the bike to coast when the motor is off or the bike it being pedaled.

    According to the Gear Ration Calculator (cool program, thank you Jim Sitton) it should be good for 30 mph or better.

    Does anyone see any probelm with my idea so far? It's kind of a take off on the Nuvinci approach to the drive set up.

    I'm a decent welder and a so-so lathe operator so fabrication should not be a problem.

    I have or know where I can get all of the scooter hardware and 5/8" jackshaft and bearings. From what I can tell it looks like I need be buy the left handed freewheel and 5/8" adapter from Staton-Inc. plus a rag sprocket mounting kit.

    Am I missing anything here?


  2. Accender

    Accender Member

    Your missing a front brake. That should be a simple fix tho.
    Other than that, It sounds good!
    Post up your progress with pics. I would like to see the build.


    Last edited: Feb 23, 2009
  3. srdavo

    srdavo Active Member

    cool idea..... I want to watch this come to life.

    are you including a freewheel, somewhere in your motored driveline?
    (so you can pedal & coast, without spinning the motor??)
  4. bjaspud

    bjaspud New Member

    The left had sprocket on the jackshaft will have a freewheel. That means the left hand chain will be moving when coasting but nothing else will turn.

  5. srdavo

    srdavo Active Member

    cool...... looks like you have it all covered!! :grin5:
  6. oldsalt

    oldsalt New Member

    The easiest and cheapest way to acquire the 5/8" jackshaft and bearings and sprockets is to go to mfgsupply.com and click on mini bike and go-kart karts. Have delt with these folks and they have proven to be low priced, exact, and quick. They carry an extensive line of items. Some are sure to be of interest you for your interesting project.