Re: A new shift concept for the engineers....
I think if you increase the chain speed wrapping the 3-speed, it can handle the 5 hp. Reducing the amount of torque that is applied through the tranny, allows you to go bigger on power.
If I sit in my scooter and pull on the drive chain by hand, I can move the scooter in first gear with my weight in it.
Currently I have a ten to one ratio between my crankshaft and the transmission input sprocket.
And the tranny to rear wheel is 1 to 1.25 with a 10 inch rear tire.
So my overall ratio from tranny input to rear wheel is