Some caveats!
Aircraft tires are not designed to be 'drive' tires. They are free
rolling, they don't push the aircraft along the ground.
The propeller or jet engine do the pushing, the tire is just
along for the ride. They are designed for the aircraft to 'land'
on (literally) and thus are built for impact loads (for some of
us pilots, the impact is larger than for others). Neil pointed out
that small tires have been tried in Can-Am and that the smaller size
limited rotor size and thus breaking efficiency. (Fortunately motorcycle
streamliners are not required to have a front brake.)
A typical cycle for an aircraft tire is to start out rolling slowly, with
lots of gross weight, and speed up with the weight slowly being removed (as
the wings generate lift) to max takeoff speed at which point the aircraft
leaves the ground and the wheel spins free - usually followed by a quick
deceleration as the brakes are applied as the wheel is retracted into the
aircraft. Next, the wheel is stuck back out into the cold air and then
very quickly accelerated to landing speed while absorbing the landing
impact.
(The wings are usually still generating some lift at touchdown, so the
full gross weight may not be felt.) Then breaking loads to slow down, and
then just roll on up to the gate/tie down/parking.
These and other implications will need to be taken into account when
designing for use of one of these tires. These tires can have a cross
section similar to motorcycle tires (rounder without a flat tread area).
For a motorcycle that steers on a cam angle this would, on the face of it,
seem to be good, for an automobile that steers on a slip angle, this could
be detrimental.
My reading of the rules would seem to make these tires legal, for cars,
"Other tires having the Manufacturer's recommended maximum speed
molded on the tire will be accepted up to that maximum speed" (2F)
And for Motorcycles "Must be Certified Land Speed Record tires or
certified by the manufacturer as to the Limits and pressures needed
or required" (7.B.8) (But this would be subject to interpretation
by the rules officials.)
Would a 50 MPH additional allowance be made for a shaved tire?
Aircraft tires 'grow' considerably at high RPM
http://www.desser.com/tech/centrifugal.html
and suffer other deformations.
We're talking lots of RPM for a small tire at 200 MPH. About 4,600 RPM.
Balance will be critical and who knows what the gyroscopic effects will
be.
As I'm planning on building a to scale trainer from bicycle parts for
'driver education', I'll fit an aircraft nose tire as the front wheel
and report back what I find.
Thanks, and THANKS to the list!
Jim W.
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