Have you tried driving a car in soft dry sand? If you have normally inflated tryes you soon sink. If you deflate your tyres, you carry on driving. Tell me it's not so and I'll ask how I am not stuck in the middle of the Sahara or the Namib.
In other words, deflated tryes offered me more grip when driving off road across Africa. How do bike tyres fundamentally differ from car tyres in this respect?
No. Your science is flawed.
You don't get more grip, you get more float, in those situations. It is not the same as on a hard surface.
You musts distinguish between situations where the substrate leaves an imprint on the tyre (in which case Van der Waal's forces contribute to friction, or the specific type of friction we're after called, traction) and, where the tyre leaves an imprint in the substrate, in which case we rely on the shear strength of the substrate to give traction.
The two modes are completely different.
In sand, the vehicle stalls because the wheels sink into the sand due to small surface area and then can't go forward because the undercarriage is jammed in the sand. With lower tyre pressure, you get bigger surface area, which doesn't increase friction but increases float.
All is not what it seems in tyre science.
