Nine mechanical engineering students at Yale have built a bicycle with a spokeless back wheel. Since they ran short of money and time as well, they could not extend the spokeless design to the front wheel. Anyhow, to construct it within a single semester is really worth the appreciation.
It’s a single speed setup. We used two cranks and two bottom brackets in the front to gear up the ratio. It goes from (IIRC) 53 to a 13, which is connected to the second crank and another 53 which connects to the rear hub. The rear hub is just a normal ratcheting rear hub that we mated to our belt pulley. Not sure if all these bike terms are right, but that’s the general idea.
The tire that you see on the rear wheel is a normal bike tire so we did use a standard wheel size. I think we aimed for 26″ initially but that might have changed.