Mathematically, circumference is PI
times diameter or 3.14159..... times
the diameter.
On 12/2/2015 11:06 AM, Fred Cisin wrote:
On Wed, 2 Dec 2015, Paul Koning wrote:
Actually, it's the circumference
that matters, not the diameter.
I always thought that there was a
relatively stable relationship
between those! :-)
Circumference tends to be a little
over 3 times the diameter (3.0 in
some states) :-)
Does the circumference of a rubber
roll change significantly when you
press on it?
If it shifts or squeezes out to the
sides, not so much.
If it compresses, yes.
Before TPMS, some cars got a crude
estimation of low tire pressure by
comparing the RPM of a tire (ABS
sensors) with its fully inflated
brethren.
(circumference changing with pressure
change)