If you don’t pedal your bike then you have a chain that you don’t use pretty much so why even have it there get a jackshaft kit and you just have one chain that you actually use. People who don’t peddle make me sick
Lets say you have a 40th rear sprocket on your bike and a 10th sprocket on the engine.
If you go down to a 36th rear sprocket you will gain top speed, if you go up to a 52th sprocket you'll have some more hill climbing power and take off
power.