3 ms·
IIRC that grip scales linearly with the downward force and is (maybe counterintuitively) invariant WRT to the grip area.
by maxhille 3y ago
IIRC that grip scales linearly with the downward force and is (maybe counterintuitively) invariant WRT to the grip area.
- knodi123 3y agothat's absolutely counterintuitive. is it because all the weight of your car is shared equally between all points of contact, so more grip area = less force per grip area?
- wongarsu 3y agoExactly. Of course that's assuming perfectly rigid wheels and ground. Tanks have tracks because they often encounter ground that's everything but rigid. Distributing your load over more area reduces the forces experienced by the ground, allowing it to stay put. Same idea with putting more wheels on a truck, or reducing tire pressure when driving in sand. Meanwhile race cars tend to have trouble with the tires not being rigid enough, driving them to bigger tires. But that doesn't allow you to exceed the theoretical max grip, and in that formula surface area cancels out.
- jecel 3y agoWhile friction is invariant with the area, adhesion is proportional to the area. Tire grip is much more adhesion (think a glue-like chemical reaction) than friction, which is why race cars use such wide tires even though that ruins the air flow.
- Sohcahtoa82 3y agoPeople keep saying this, but if it was true, why would high-performance cars need wider tires?
- knodi123 3y agoNow you have me imagining a penny-farthing with an F1 engine.