Lowracer1's right, 'bent riders have been doing it for years.

Front and rear Coroplast spoke covers. The yellow wheels just right of center are 4mm Coroplast.

Styrene/ABS spoke cover, only one side installed and showing flap for inflation. This plastic is the same stuff that 'For Sale' signs at the hardware store are made of.

If you want to go lighter, you can make 'W' shaped brackets out of carbon fiber, get fiberglass kite spar material to make a hoop, and make spoke covers out of ripstop nylon.

Cool? yeah! Patentable? Probably not...