Jackshaft Jackshaft idea

Discussion in 'Transmission / Drivetrain' started by macarollo, Aug 3, 2008.

  1. macarollo

    macarollo Guest

    I have tried to search, but have not found it.

    I just ordered a 80cc blue collar bike kit.

    Is it possible to use the crank as a jackshaft and then connect to the rear gears that are shiftable?

    I know on tandem bikes there is a gear on both sides of the crank. Is it easy to change the crank out with one that has a gear mounted on both sides? I think I would remove the pedals and make it power only if I did this.

  2. Ghost0

    Ghost0 Guest

    In theory it can be done but transferring the engine output to the bottom bracket is difficult to line up with a standard frame. We have done something similar using a jackshaft and a front freewheel. You can see it by looking at our website located on the left of the screen or in my signature.
  3. Skyliner70cc

    Skyliner70cc Active Member

    Buy the kit from sickbikeparks.com. They've taken all of the guesswork and done the hard work already.
  4. tpelle

    tpelle New Member

    You know what? This might be the answer to the problems that seem to arise from mounting the rear sprocket to the wheel spokes - that always seemed to me to be the weak point of most of these motor-bicycle conversions. Even with a single-speed bike, you would probably gain reliability, and would still be within the letter of the law in many States (no transmission requiring the shifting of gears after the engine is engaged).

    With a good-quality three-speed internally-geared hub, though, this would be really cool - though it would be a motorcycle where I live.
  5. Skyliner70cc

    Skyliner70cc Active Member

    Get a nuvinci hub and there are no "gears" to shift. Its a gearless CVT.
  6. macarollo

    macarollo Guest

    $400 is more than I am willing to pay.
  7. SimpleSimon

    SimpleSimon Active Member

    Strictly speaking, you still must manually shift the NuVinci.
  8. Skyliner70cc

    Skyliner70cc Active Member

    Only if you want to and there is no visible derailleur to tip off a police officer that you have a multispeed transmission.