CVT happytime + cvt?

Discussion in 'Transmission / Drivetrain' started by ecgoeken, Jan 2, 2010.

  1. ecgoeken

    ecgoeken New Member

    i have been reading through all the posts here and i didnt notice anyone using a pocketbike cvt with a happytime motor. i have the usual 66cc chinese kit, and have trouble taking off from a rest position without pedaling/killing the engine. ive been thinking about using one of these pocketbike cvt's to get the torque needed to take off from a dead stop. i was wondering if anyone out there has added one of these transmissions to a happytime motor?

  2. give me vtec

    give me vtec Active Member

    nope... but my nuvinci cvp hub works great.
  3. ecgoeken

    ecgoeken New Member

    yeah, those look pretty nice. unfortunatly theyre also expensive. plus, my only breaking is through my coaster breaks, so changing my rear hub out would be a pain. i was just thinking about the pocketbike cvt and thought of another problem i might have if i add one. i would have to get rid of the clutch arm if i were attatch it directly to the motor. however if i did this i wouldnt be able to ride it like a normal bike anymore because there would be no way to disengage the motor (i think these cvt's engage when you start riding so by pedeling you would engage the motor....i think). i would have to mount the cvt separetly and hook a chain from the motor to the cvt and then a chain from the cvt to the rear sprocket. the clutch arm would then basically be like a switch to go from "bike mode" to "motorbike mode"
  4. ecgoeken

    ecgoeken New Member

    sorry, i think i was wrong in my previous post. pedaling the bike wouldnt engage the motor. from looking at these cvt's, pedeling would rotate the bell of the transmission but the thing that engages the system is attatched to to motor and would not rotate and therefor not engage. i could just scrap the entire clutching system that came with the motor. well, i guess im just posting as im thinking, if anyone has tried this i would like to hear how it went for you and if you have any tips.
  5. Youngbird

    Youngbird Member

    You need a centrifugal clutch to run a there such an animal for the HTs? Im not a 2stroke guy, so just asking.
  6. ecgoeken

    ecgoeken New Member

    if the cvt works like i think (theres a good chance it doesnt) then the centrifigal clutch could be bolted where the engine sprocket would usually go and then a bracket could be fashed to fit the cvt over the clutch. i might have to just go ahead and see if i cant get it to work, those cvt's are only like $60-$70.
  7. loquin

    loquin Active Member

    The HT engine has an internal gear reduction of about 3.6 to 1 (22:80,) so, the CVT RPM may never get high enough to shift the shives on it...
    Last edited: Jan 4, 2010
  8. ecgoeken

    ecgoeken New Member

    you have a good point. for the price it might be worth goin for it. still would like to know if anyone out there has tried it?
  9. Goat Herder

    Goat Herder Member

    I am eagerly waiting for some to try this out I want to do one with a Morini.
  10. arkives1

    arkives1 Member


    There are centrifugal clutches available from Zoombicycles, I have two bikes using them on Power King engines. I don't know if they will fit other engines or not but would think so as they do seem to be configured the same. You are simply replacing the small gear on the clutch plate side with the centrifugal clutch and adding a deeper cover. I noticed that mine were a bit slower on take off but still gave me good top speed. I do not need to pedal to start riding if I don't want to, it acts like an automatic transmission. You might need wider pedal cranks to clear the housing, I did but I also have pull starters on mine. Woody
  11. AussieSteve

    AussieSteve Active Member

    Probably a typo, Lou, but the HT engine internal gearing is 4.1:1, (82:20).
    (I just spent half the day calculating ratios for my shift kit and know them all backwards now.)
    Still, I don't doubt that you're right about the CVT RPM.

    ... Steve
    Last edited: Feb 7, 2010