i was riding my 4 stroke bike today and with a 44t sprocket it was painfully slow. lots and lots of torque going to waste.  i looked at it later and couldn't see any reason why a freewheel crank jackshaft wouldn't work with it. brackets for the shaft could attach to the mounting plate.  changing gears would be super easy with the c-clutch. maybe im missing something but looks fairly simple.
	
		
			
		
		
	
				
			
	