Carbon fiber...or magic!

Anyhow, the rim is actually a very large roller bearing with the tire attached to the outside. The steering column would be attached to the interior, stationary part of the rim.

Actual moving vehicles have been built with this technique and it is sound. Here's one now:



This page features one that might actually be rideable.
http://www.osmoswheel.com/pages/application_cycles.asp

The seatpost could be attached to the fixed portion of the wheel which would be in turn attached to the frame. You could then attach a drivetrain to the rear wheel which actually has a hub.

The handlebar and steering column would be attached to the interior of the hub and the brake would come into contact with the braking surface on the moving portion of the rim. At the bottom of wheel it would attach to the front of the frame with a pivot that would allow you to turn the wheel...at least to the left.

Of course you could combine the two ideas, borrowing the rear wheel and drivetrain from one and the more sensible steering from the other