My 2 cents-
I have a HF 79 powered bike. Belt to jackshaft ( bought ball brg. pillow blocks from Mcmaster Carr - if you pay w/credit card. -no problem).
I used 1/2 inch size because I had some pulleys that size. No keyways. Grind a flat where the set-screw goes and lock it down real good and you are golden.
That jackshaft runs by # 25 scooter chain and sprockets to another jackshaft which IS (now) a 3 speed Stumery Archer hub.
The hub is bmx chain drive back to a HT sprocket (grind down or adapt a bike chain ring to it).
Your idea of going 35 mph with one gear will not work unless you pedal real good to get started and THEN engage the clutch. The 4 stroke doesn't rev like the china engines. It will be like you are trying to take off with a car in high gear.
The double jackshafts allow me to have a freewheel and smaller pulley sizes.
I stretched the bike frame 3 inches and put the engine up front.
I widened the one piece crank like it was mentioned before.
I run the stock governor and it is great- like cruise control.
I have a HF 79 powered bike. Belt to jackshaft ( bought ball brg. pillow blocks from Mcmaster Carr - if you pay w/credit card. -no problem).
I used 1/2 inch size because I had some pulleys that size. No keyways. Grind a flat where the set-screw goes and lock it down real good and you are golden.
That jackshaft runs by # 25 scooter chain and sprockets to another jackshaft which IS (now) a 3 speed Stumery Archer hub.
The hub is bmx chain drive back to a HT sprocket (grind down or adapt a bike chain ring to it).
Your idea of going 35 mph with one gear will not work unless you pedal real good to get started and THEN engage the clutch. The 4 stroke doesn't rev like the china engines. It will be like you are trying to take off with a car in high gear.
The double jackshafts allow me to have a freewheel and smaller pulley sizes.
I stretched the bike frame 3 inches and put the engine up front.
I widened the one piece crank like it was mentioned before.
I run the stock governor and it is great- like cruise control.