Jack shaft tooth belt drive system

Discussion in 'Rack Mounted Engines' started by kerf, Dec 24, 2008.

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  1. kerf

    kerf Guest

    I ran across this chrome bike on an Asian site that looked pretty good. Can't find the site anymore but I kept a picture of the drive train. Looked really neat, maybe someone would like to reverse engineer this thing.

    Attached Files:

  2. DetonatorTuning

    DetonatorTuning Active Member

    this is "sort of" where i'm going BUT, this setup is still having the final drive belt pass the tire which as we all know leaves you just the 9mm wide belt to work with.

    to improve this you have to get the jackshaft and the secondary reduction drive pulley BELOW the rim and in closer to the spokes.

    3/4" wide belt is easy to accomodate if the positioning is optimized.

    not to thread jump BUT i'm still working on it. in order to have wider application my setup is becoming less innovative and more derivative almost daily. :-/

    i've GOT to make some moves VERY SOON or the wife will have laid waste to my bonus and i'll have no "veture capitol" :icon_cry:

  3. kerf

    kerf Guest

    All you would need is a longer primary belt and a shorter secondary belt. Goes without saying the JS housing would need to be longer. The neat thing was the drive train was mounted on what looked like a steel rear luggage rack. Also the final drive was to the hub not the spokes, maybe a disk brake rear hub.
  4. Silvaire

    Silvaire Member

    YES, that is a VERY clean looking drive.

    If the designer would improve it by:
    extending the primary drive down below the rim,
    lowering the engine height as far as practical,
    including a quality 4 stroke engine as an option,
    using either a free wheel or lock-up on the wheel pulley,
    and then offer it for sale,
    I'll be the next in line to buy one!

    One can only hope that this is the beginning of a commercial product that will someday come to market.
  5. Happy Valley

    Happy Valley Active Member

    Kerf, any chance you can find that page again where you saw this set up?
  6. srdavo

    srdavo Active Member

    I would love to see the real numbers on all that gear reduction.
  7. spad4me

    spad4me Member

    Livefastmotors sells a chain-drive version if your picture.
    Look at the bottom of the page.
    Chain-Drive Kit

    Both a 2 stroke and a 4 stroke version.
    It would not be difficult to ask them for the particulars. ie the stages of reduction to make a belt drive copy.
  8. kerf

    kerf Guest

  9. srdavo

    srdavo Active Member

    Dang, kerf.....It's no wonder you couldn't find it again....that site has everything!!
    I did find a 175cc trike w/a dump bed (for old men!!)
    & a Turkish Proctology table w/ 2 motors & adjustable footrests....?!?!?

    From what I saw, there wouldn't be any tech info anyway.

    If we guess 4:1 on the primary & 5 or even 6:1 on the secondary, that would put us close.
  10. Happy Valley

    Happy Valley Active Member

    I can't tell for sure but would you say that's definitely a toothed belt on the secondary?
  11. kerf

    kerf Guest

    I believe both primary and secondary are toothed belt. From my experience,
    total reduction should be between 18-24/1 depending on engine and rider weight. I'm running an R460 with a high range of 18.75/1 and a low range of 23.08/1.
  12. skyl4rk

    skyl4rk Guest

    What is the correct terminology for gear reduction? How do you calculate it?

    Is this example correct:

    Motor gear teeth: 11
    Jackshaft input gear teeth: 36
    Jackshaft output gear teeth: 11
    Wheel sprocket teeth: 44

    Primary reduction: 36/11 = 3.27
    Secondary reduction: 44/11 = 4

    Total reduction: 3.27 x 4 = 13.1
  13. kerf

    kerf Guest

    Answer: Gear Reduction.

    Your numbers are correct.

    Final drive 13.1/1 (thirteen point one to one)