Re: 3 Piece Wide Crank??
I used short crank arms, but likely that will only work well if you do not plan on pedaling much. I built my bike to mimic an early motorcycle and to cruise on motor power- exercise is found elsewhere.
With the short crank, the arms do not reach the engine and are below it. The arms clear the rear bolts on the Grubee mounting plate by 1/4" on each side even using a standard bolt (though 7mm, not the stock 6mm), a washer and an 18 ga metal plate to pretty up the plate.