Glenn.
Have you heard about air bearings?
Won't work on bikes. But makes you wonder.
http://www.westwind-airbearings.com/...ing/index.html
"What is an Air Bearing?
An air bearing is a non-contacting system where a gas film (typically air)
acts as the lubricant that separates the two surfaces in relative motion."Types of Air Bearing
There are two main kinds of air bearing:
Aerostatic:
Externally pressurised: A separate external supply of air is fed under
pressure between the two surfaces being kept apart.
It is a continuous flow system where pressurised gas from the source
flows through restrictors into the clearance between the bearing surfaces escaping to the atmosphere at the outside edges of the bearing.
Types: Simple orifice fed, Pocketed orifice, Slot fed and Porous.
Aerodynamic:
Self generating: The supporting film is generated by the relative motion
of the two surfaces being kept apart.
An aerodynamic bearing can be of several types. The design characteristics
differ greatly between journal and axial bearings and they can suffer
problems of instability.
Types: Simple cylinders, Tri-lobe, Grooved (axial / herringbone / spiral)
and Stepped.