Its a cool concept, but i have no faith in it. The wheel will not be reliable at all, i think you will be buying cores and urethane left and right, because stuff will be breaking alot with how we ride, the angles we land with our force will be destructive to where the urethane is sandwiched by the core. But i could be wrong.
on paper its a good idea, but in practice i just cant see this working. they would always be weaker than normal wheels in the core and urethane, they would dehub all the time. making them would be difficult, meaning prices would be high. they would just be a pain in the ass to use.
if it were to work, i would think it would have to have a band of metal in the urethane that screws to the hub with a lot of little bolts.
Only one way to really find out if it does work...
Someone who has the money to invest in having these built and sending them off to some of the best riders out there.