You should be able to, it's just tough plastic.Though there is enough "meat" toward center, it looks like it would be important for the belt no to be more than 9mm at it's widest, the outer wall that holds the belt is quite thin, and I don't know if it could take the sideways pressure.That's one place the whizzer sheave will always be superior.Got it almost all figured out, just one last question. Can I file down the teeth on the gebe sheave to use a v-belt? I found a belt pulley clutch for 5/8 shaft and with a gebe sheave my cruising ratio would be 12:1 exactly, which is fine.
Id love to see a pic of your drive hoop methodRemember K.I.S.S.? You fellers are thinking way to hard! I've built 3 happy Time kits. Scratch built 2 rear rack V belt drives and 2 front wheel drive V belt drive motorized bikes. V belt drive is with out a doubt the most trouble free way, chains are dirty, greasy and drag like hell.
What you do for the giant pulley/sheave on driven wheel is take the rim/ hoop of a smaller doner bike and zip tie it using hoops spoke holes to the spokes of the bigger build bike wheel ie. (26" hoop / 700C wheel) (24" hoop / 26" wheel). The large hoop/pulley with a 1.5" pulley on motor shaft will give you about a 30 mph top speed.