Smallest motor kit available?

[INTP_ty]

Who sells the smallest engine kit? It can be 2 or 4 cycle. In-frame is mandatory (no friction drive).

I see 49cc, but anything in the 20's or 30's?

 

[FurryOnTheInside]

I don't think it exists. Not as a kit. Thing is after you've built a decent bike using the 66cc kit you probably have all the skills and tools and knowledge you need to mount a tiny engine and sort out a drivetrain for it.

I think it'll be revving it nuts off just to make enough power to move you.

Also engines that are not made for a bicycle are always too wide to go between the crank arms. Even the 4-strokes and the electric start 2-stroke that are made for bicycles are too wide.
It'll have to go high up, or you'll have to give up the ergonomic design of the bike's cranks, which is bad because you'll need to pedal a lot more with the tiny engine.

There's a 38cc or something 4-stroke but it's a rack mount friction drive kit.

 

[MotorBicycleRacing]

Who sells the smallest engine kit? It can be 2 or 4 cycle. In-frame is mandatory (no friction drive).

I see 49cc, but anything in the 20's or 30's?

Why do you want a 20 to 30cc?

 

[INTP_ty]

Why do you want a 20 to 30cc?

Stealth

My 66cc on my road bicycle will do 35mph bone stock. I have more power on tap than I need. Way more.