Center of gravity 20" vs 26". How much does your engine weigh?

Discussion in 'General Questions' started by boyntonstu, Jan 11, 2015.

  1. boyntonstu

    boyntonstu Member

    The axles of 20" bikes are by definition 3" closer to the ground than 26" bikes.

    If you make both seat heights equal, there will be lots of room below your seat on a 20" bike for engine mounting.

    I am not positive, but it may be possible to rear mount an engine on a 20" bike and have a low CG.

    Last edited: Jan 11, 2015

  2. KCvale

    KCvale Motorized Bicycle Vendor

    Sure, on a girls bike with no top bar, or do you plan to mount the engine on top of the top bar?

    If you attach the engine to the side of the wheel at the axle maybe but then the weight is not centered, above the wheel of course not a low center of gravity.
  3. darwin

    darwin Well-Known Member

    Most kits it doesn't matter once you get into motion. Even a FD weighing 20lbs on the rear weighted to one side you don't even notice the weight, not an issue in my book.
  4. SunkyWorks

    SunkyWorks Member

    Heres a over 30lb Lifan 97cc/2.5hp Friction Drive.

    Getting a working kick-stand becomes more of an issue.

    Not my MB.

    Attached Files:

    boyntonstu likes this.
  5. boyntonstu

    boyntonstu Member

    Nice! What is the gear reduction?

    How is the tire wear?
  6. SunkyWorks

    SunkyWorks Member

    Sorry, not my build.
    It's from the other forum, and it might not be proper to link.
    Google "Lifan 97cc/2.5hp Friction Drive"

    Tire wear tends to be about 20% worse on friction drives than other drives.