You will need a crazy big sprocket and a custom adapter or multiple jackshafts to get a suitable reduction.
A 1 inch roller turning a 26 inch wheel will have a 26 to 1 reduction ratio. 16 to 1 is generally preferred for the forced air cooling engines since they can run high rpm without major heat problems and you still get a decent top speed.
Get into crazy tooth counts for that. A 10 tooth driver would need a 160 tooth driven sprocket or compound reductions. Biggest I have ever seen is a 85 tooth for #35 chain.
The Staton gearboxes use a triple reduction.
Belt drive is an option, but I'm not sure how easy it will be to find a 16 inch pulley, let alone attaching it to the wheel. I have seen some guys use a bike rims but those aren't exactly purpose built for the application. A 20 inch rim should do it, though you'll have to size your belt for the rim rather than the driver, which complicates that.
