Originally Posted by meep
…….. #1: Contact patch area is determined by the weight on the tire and the pressure in the tire. 800 lbs over a tire inflated to 40psi will yield 20 square inches, regardless of tire size. ……
Actually, that is not correct. It's a widely held myth, but the tire's stiffness plays a large role, not to mention the tire's geometry.
As an example, a RunFlat tire would have a sizable contact patch, but zero inflation pressure. The same is true of highly inflated tires - like over the road truck tires.
Unfortunately, for passenger cars, the size of the contact patch sort of follows that formula, but that is only by coincidence, not by the physics.
However, the rest of what you wrote is pretty much spot on - that low aspect ratio tires have wide but short contact patches, it's just that their contact patches aren't exactly the same as higher aspect ratio tires. In fact, low aspect ratio tires have LARGER contact patches, all other things being equal, but only a bit bigger.
…….. #1: Contact patch area is determined by the weight on the tire and the pressure in the tire. 800 lbs over a tire inflated to 40psi will yield 20 square inches, regardless of tire size. ……
Actually, that is not correct. It's a widely held myth, but the tire's stiffness plays a large role, not to mention the tire's geometry.
As an example, a RunFlat tire would have a sizable contact patch, but zero inflation pressure. The same is true of highly inflated tires - like over the road truck tires.
Unfortunately, for passenger cars, the size of the contact patch sort of follows that formula, but that is only by coincidence, not by the physics.
However, the rest of what you wrote is pretty much spot on - that low aspect ratio tires have wide but short contact patches, it's just that their contact patches aren't exactly the same as higher aspect ratio tires. In fact, low aspect ratio tires have LARGER contact patches, all other things being equal, but only a bit bigger.
