Deraileur Transmissions

Discussion in 'General Questions' started by TomMelee, Jun 19, 2008.

  1. TomMelee

    TomMelee New Member

    I've got a very neverending supply of large chainsaw engines...39-50CC's. I have to buy them, but they generally go for under $30 each brand new. Anyway, I have a happy time motor, want to play with putting one of these chainsaw motors on another bike. Really, REALLY looking for anyone who has successfully rigged up a pseudo transmission using the rear deraileur of any given bike. (Especially if the bike is still pedal-able, we have lots of huge hills around here.)
     

  2. darwin

    darwin Well-Known Member

    I cant wait to read the specs on this setup and please post pics too.
     
  3. Ghost0

    Ghost0 Guest

  4. darwin

    darwin Well-Known Member

    Nice bike and excellent workmanship. Isnt a deraileur the mechanism that shifts the chain from one sprocket to another? In the original post he specifically states rear deraileur.
     
  5. Ghost0

    Ghost0 Guest

    Well the bike is pedal-able, and can shift, under both engine and pedal power using the rear derailluer. I thought that is what he was talking about.
     
  6. TomMelee

    TomMelee New Member

    I had actually seen both those threads, but was hoping to avoid the jackshaft via rear mount above the rear tire, and physically using the rear deraileur. It occours to me that the rear cassette is perhaps too tall for the motor, though.
     
  7. Ghost0

    Ghost0 Guest

    By too tall I assume you mean gearing, you would need to reduce you engine axle speed substantially prior to hooking up with the rear cassette. You would also need to move your derailluer so that it would pick up the chain as it enters from above as opposed to the front, but if you do that then you couldn't pedal it anymore. I guess 2 chains would be an option but shifting either or both would be a dicey proposition.
     
  8. TomMelee

    TomMelee New Member

    Right, thus my conondrum. My real reason for wanting to pursue this is that I live in the mountains here and hills are a real issue. My little HT motor isn't anywhere near broken in yet, and it really does ok on them, but I believe that it can do waaaay better. Like I said, I saw a fellow way bigger than I am pulling quite a grade without pedaling at probably 30-35mph, and his motor didn't appear to be any bigger than about 50cc. It was mounted directly above the rear wheel, and I didn't see a friction drive as per the GEBE kits.

    The cost of the jackshaft kit is the real killer for me on your front sprocket setup there. If you've got any messenger program (msn/aim/yahoo/whatever) I'd love to pick your brain a little closer to "real time."
     
  9. Ghost0

    Ghost0 Guest

    Most likely what you saw was a 4 stroke rack mount kit. 4 strokes have good torque. I don't use IM's, not that kind a guy. Send me a PM and we'll talk.
     
  10. darwin

    darwin Well-Known Member

    Tom after looking at ghosts setup isnt that exactly what you want? You could have a 6 or 7 sprocket cassete on the rear and that would give you the gears to choose from.........nice setup ghost.
     
  11. TomMelee

    TomMelee New Member

    It is what I was hoping for---it's just something that I certainly can't fabricate in-house and really don't want to throw another $200 at. His system makes a lot more sense than the idea in my head, it's just more than I'm currently capable of.

    What kind of end product did you get Ghost? Top speed? Hill climbing?
     
  12. Pablo

    Pablo Motored Bikes Sponsor


    I'm not Ghost0, but I am his 50/50 business partner (we formed an LLC).

    The final product will be a complete kit. There some nice options for your build. You can paint the brackets any color you like, for example. Top speed depends on a lot of things, but with the standard (right end) shaft driving gear on my well tuned 70cc mountain bike, I hit 35-40 mph in 4th with 5th and 6th to go. Low end hill climbing is amazing, especially with an 8 or 9 tooth shaft driving gear. Like a trials bike. 8 tooth is so low that there is not a ton of difference with first or second on the rear cassette.
     
    Last edited: Jun 26, 2008
  13. TomMelee

    TomMelee New Member

    That's bien, but when might it be available? And how much?
     
  14. Pablo

    Pablo Motored Bikes Sponsor

    $199 + shipping

    Mid july
     
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