Gearing question??? help needed

Discussion in 'Bicycle Repair' started by rkbonds, Oct 31, 2008.

  1. rkbonds

    rkbonds Member

    Ok here's the details and question: I have a 24cc weedeater motor, 18 tooth drive gear, 26" mtn bike with slicks going for chain drive. What size gear should I use on the wheel? I have gear selectons from another 18 tooth and up. I'll take any speed over 12 mph.........:?::cool:;)

  2. Alaskavan

    Alaskavan Guest

    I think the overall ratio for a 26" bike is around 18:1. So multiply your drive gear by 18. That should get you into the ballpark. You will probably need reduction.
  3. loquin

    loquin Active Member

    No doubt. With no reduction, you'd need a 51 inch diameter driven sprocket... :(
  4. 5-7HEAVEN

    5-7HEAVEN Guest

    You will definitely need a jackshaft.

    The biggest change is at the engine. Drive sprocket MUST be downsized, preferably to 10-tooth. That chains to a 32-44tooth jackshaft. The next 9-tooth hooks to a 50-tooth sprocket on the wheel.
  5. Esteban

    Esteban Active Member

    Much simpler to go to a friction drive, if yuo would take that.
  6. rkbonds

    rkbonds Member

    I have a friction drive now, I was just wanting a more "positive" drive system. That way if it rains I'm still motoring along with no difference in capabilities.
  7. Alaskavan

    Alaskavan Guest

    I totally understand. My most reliable motor is my TLE43 on a friction drive kit, but I don't ride it much because of the weather. Check out Haggard's tutorial on pocket bike engines. He shows, step by step, what you need to do to go chain drive.
  8. howry

    howry New Member

    <new in here>
    what do you mean friction drive kit?
    and whatz up with 16:1? can you guys explain me that?