Need Tiny Motor with Big Power

Discussion in 'Performance Mods' started by WisdomWarlord, Apr 4, 2012.

  1. WisdomWarlord

    WisdomWarlord New Member

    I am going to motorize a dual suspension bike, so typical frame mount is out. I don't want all that weight up high and over the back wheel, so rear or front rack mount aren't really options. So that leaves me to my crazy idea.

    I want to extend the swing arm by enough to mount an engine in the swing arm, ahead of the tire. So, space is really really tight, especially considering the crank arms will be swinging around there too, meaning heat shields on both sides, and behind to protect the ire. Really tight space.

    I'm not looking for a speed demon. I will be very happy with 25mph on a flat smooth road. 30-35 would be nice, but 25 is fine.

    So, I'm thinking that a small displacement 2 stroke and a friction drive will suit my needs. Nothing bigger than 25cc, and maybe as small as 19cc.

    I am hypothesizing a friction drive mechanism that is a 3 speed setup, very compact and not too heavy, but right now it's only a theory. At the least it will be a 2 stage jackshaft setup driving a single speed friction wheel.

    My question is, what engine do you recommend? What types of engine mods will give me the most bang for my efforts?

    Also, given the low power needs, I am expecting stock bicycle gears and chains, properly lubricated, to provide reasonable service, and making replacement parts cheap, plentiful, and easy to get quickly.


  2. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    eBike friction drive.

  3. WisdomWarlord

    WisdomWarlord New Member

    Psychosis Ensues

    Ok. Forget what I said up there. I now have in my possession a Honda GX110 4 stroke horizontal shaft engine.
    So. Plans have changed. I am going to make this engine work!