snip


If I was doing an electric motorcycle, I would use a DC motor and
several small, garden tractor type batteries. I would select how many
batteries are in the circuit to control voltage and speed.

Different strokes for different folks. Going the VFD route has a lot of
merit. 20 garden tractor lead acid batteries would be around 300 pounds,
fit in a space 20"x32" x7" high.


I see not much reason to use inversion, AC, phase conversion etc.

Using all electronics might not be cheap but the VFD unit only weighs 20
pounds or so, is completely computer controlled with lots of feedback on
speed and torque, and frees you from all the heavy duty contactors and
similar.

Downside is that there is not a lot of avialable torque at low speeds
where you need it the most.