Take a look at this rather bizarre bike. Apart from the fact that its wheels don’t have spokes, they’re not round either.
The front wheel is a rounded off pentagon while the back one is a reuleaux triangle (yeah, I went to Wikipedia too).
Apparently it’s quite smooth to ride, though it wasn’t completed in time for the Beijing Olympics that it was supposed to be in sponsorship for.
Never mind, it wouldn’t have won any medals.