list:

another apparently weird thing is how normal it can feel driving on an
otherwise intact tire at 0 psig. at 0 mph the van justs sits on the rim.
at 70 mph, however, it takes centripital force to keep the tread going
around, which is provided by internal tire forces all the way around
except at 6 o'clock, where the ground pushing up on the contact patch
provides the necessary force, which is just sufficient to support the van.
as the vehicle slows down the contact patch grows in area inversely
approximately with speed squared, and it rapidly becomes obvious that the
tire is flat.

daniel

On Tue, 18 Nov 2003 15:25:03 -0600, tom ring <taring@TARING.ORG> wrote:

>While going down to Flagler Beach from Minneapolis, I was tooling along
at 70
>in the right lane just north of Atlanta.  A car with a couple youngsters
in it
>go by in the 3rd lane at about 85, brake mildly, drift back next to me
and the
>passenger rolls down the window.  Waves his arms at me, gets my attention
and
>makes roll down the window motions.  I roll down my window and he
yells "You
>have a flat tire!".  Hm, I think, doesn't feel like I have one, but I
pull off
>onto the sholder and coast down to 20 before touching the brakes.  I
check, and
>sure enough, I've been sitting above the flat tire.  I blow it up a bit
with a
>12 volt compressor, noticing the stem is bent over a bit by the wheel
cover,
>but think nothing of it.  I get to a tire store, have the thing checked,
and
>not a leak is to be found.  It happened again while in FL, but I noticed
it
>before the tire went flat.  I drove back home with all 4 wheel covers in
the
>van.  I'm still running on the same tire 15000 miles later, but with old
style
>moon hubcaps.
>
>tom