The sidewall-less tire thread made me think of this:
<IMG SRC="http://www.amenmotorcycles.com/reform/aments/bikes/hub.jpg">
I have no idea how it works. But it's damn cool.
<IMG SRC="http://www.amenmotorcycles.com/reform/gallary/hublessfronta.jpg">
<IMG SRC="http://www.amenmotorcycles.com/reform/gallary/hublessbacka.jpg">
Amen makes some crazy shit.