full belt drive....CVT?

Discussion in 'Frame Mounted Engines' started by wildwestrider, May 6, 2009.

  1. wildwestrider

    wildwestrider Member

    Im contemplating a build using an alu frame Felt and a Honda GXH50. I would like an all belt drive using good old V belts for an authentic Look.

    Can this be done without using any kind of a gear box or jack shaft,...or does there need to be a gear reduction of some kind. I would consider any solutions, but cheap and durable would be Key,....not looking to make it complicated. I would consider an old fashioned mechanically actuated slipper clutch with a belt tensioner or a plain old centrifigul clutch....but wonder if that would impact the ability to pedal the bike in an emergency.


  2. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    Have you seen a Whizzer?
    It's all belt drive and there are two belts because you need that much reduction.
    You need gear reduction if you mount the Honda 50 in the frame, either a jackshaft or a gearbox of some kind.

    Golden Eagle is the only single, direct belt drive but that is a rack mount
    with it's own peculiarities.

    There is a ratio calculator you can download on site which makes it EZ :devilish: to figure it all out and is fun to play with....

    Last edited: May 6, 2009
  3. wildwestrider

    wildwestrider Member

    Yes, familiar with the Whizzer,..at least from online discussion and pics,....but none available locally,....I have had a craigslist ad running for a month looking for one.

    If I do a jackshaft, then the new drive output is now on the right side of the bike. Have considered doing this using the jackshaft and freewheel kit from sick bike parts,...it will also give me some gears to shift......I was just hoping for that authentic look of the belt drive on the left side without a lot of expense or complexity. I know that Hough-Made uses the GXH50 with a gear box that gives him left side belt drive.....maybe that is the only way.
  4. ocscully

    ocscully Member

    With a jackshaft the out put driver doesen't necessarly have to go to the right side of the bike, it can stay on the left. Besides the amount of ratio reduction required the other problem you need to overcome when using a belt is the fact that the belt is a closed loop (does not come apart like a chain) So getting it to clear your chain stays and seat stays can be difficult. It can be done, It just requires a bit of fabrication, and there for some extra expense. Do a search for the terms belt drive and read the various threads to become aware of the challenges that are ahead and good luck with you project.

    http://www.motoredbikes.com/showpost.php?p=120973&postcount=1 Here is a link to a guy who mapped out a v-belt system for a frame mounted Honda 4-stroke,

    http://www.amazon.com/Power-Twist-V...77-7559519?ie=UTF8&s=hi&qid=1241661850&sr=8-1 This is a link to a particualr type of belt that works in v-belt pulleys that could help in clearing the stays of your bicycle as it is designed to come apart.

    Houghs bike is chain driven not belt.

    Last edited: May 6, 2009
  5. Either side drive works.

    I have driven jackshafts from both right & left sides. Check out my photo gallery Zack is left side drive jackshaft with the Honda 50. Zena & Bob both are driven on the right side with same jackshaft designs. Staton-Inc sells all the components. Search for my Thread Zomby Zack an old school chopper from scratch. There are detailed pics there. You could belt drive this same set-up. No prob.
  6. wildwestrider

    wildwestrider Member

    Looks like you have a Honda with a right side output shaft...does such a thing exist or did you somehow change the direction of rotation of the engine?
  7. Gear box

    The gearboxes dictate the drive direction. All Hondas output drive on the left as do all of my other motors. Zacks gearbox drives left. If you notice, I don't have any reduction through the jackshaft on that bike. It would be entirely possible to not use a gearbox. Use a very small pulley off the motor & a big one on the jackshaft. You could still use a centrifical clutch to drive the pulley. Anything is possible. With my setup, it takes a LOT of width for the motor, adapter, clutch, and gearbox. I don't know if you could squeeze all that into a stock bikes frame. You could if you were to eliminate the gearbox & adapter. My crank is very wide & it still has a 1 1/2 inch extension off the right pedal. The motor is centered in the frame & balanced pretty well. By the way, these wide cranks are rarer than a 4 leaf clover so if you find a supplier - buy 2. Oh & please let me know who that supplier is...