Tire Pressure/Contact Area/Weight

jadatis wrote:
The picture of the footprints from capri-racers article give that much more pressure on the ground at the given pressures, that you can explain it by the overall surface minus groves and the sidewals press a bit more to the ground.
Even at the 16 psi most of contact is about 20 psi but even at the edges at the sidewals some spots up to 90 psi.

I also have a pressure loadapacity list from Michelin wich has 3550 kg at 6 bar with 777cm2 contact surface given .
this thoug would mean when supposing bar to be the same as kg/cm2, wich it is almost.
3550/6= 591 cm2 so this would imply that my theory of a part of the load being bare by the construction of tire to be wrong.
But how accurate is this given?

But if you would put the tire on a blunt nailbed it would give the same bending so total surface included the grooves .

I also calculated in that list for 1400 kg 1.8 bar so can be because of rounding 1.7 to 1.8bar. given
Then the 777 cm2 surface comes closer. Asuming again 45kg bare by the construction gives 1355kg/777cm=1.75 kg/cm2 <> 1,75bar.

That is more to the idea I have about that higher pressure makes tire stiffer so at same deflection lesser surface(length) on the ground. For 3550kg at 6 bar it would give 3505 kg//5,95kg/cm2=590cm2 to be the surface on ground inclusiv grooves.

Here a picture I made for it to show how the surface lenght can be smaller for a stiffer tire, even if the deflection is the same.
The smaller surface at same deflection becomes because of the larger overgoing curve from unloaded tire radius to flat on the ground.



OK also the picture of the list I got it from , notice the 777 at the bottom.