Those Yale guys have managed to do what the bike manufacturers could not: invent an actual spokeless working bicycle that anyone can ride today. Those other concept bikes you may have seen that purportedly feature hubless wheels? They still remain as concepts the last time we looked.
This bicycle from Yale has no hub, no spokes, and practically nothing else in the middle of the rear wheel. The inventors explained that a similar front wheel was in the works, but they ran out of time during the semester. Designing the front wheel, they added, would even be easier, since they won’t have to factor in the drivetrain.
The Yale inventors posted this description of the drivetrain on Reddit:
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 front wheel would be almost exactly the same as the rear wheel except that it could be a little lighter. Some of the aluminum can be shaved off since there’s no powertrain to connect to.
The wheel/rim itself is made from T6061 aluminum.
However, some observers are already saying that calling this bike as a true “hubless” working model would be far off the mark, since they see lots of hubs in the design. Better off calling it spokeless, then.