Rad Rides by Troy is Troy Trepanier. He did the Blowfish Barracuda.
I'd like to see one opened up. It looks like the inner cap comes off to remove the wheel; but it might be a lot of work to change a tire. I notice the front wheel has an external valve stem but the rear doesn't.
I'm curious how much clearance is needed for sidewall flexing. Since the cap is moving with the tire, it wouldn't rub—just sort of press and release with each rotation.
With a convex shape and close fitting fenders it would be like a [front-]wheel fender skirt.