Tire Pressure/Contact Area/Weight
If you inflate a tire to 50 psig. If the contact patch of the tire is 6" x 12" (74 inches square). Is the weight on the tire 3700#? :h
Forum Discussion
DougE wrote:
Not real life numbers. Just a mathematical example to test the hypothesis and start a discussion on a cold winter day. If true, could be a way of figuring weight on each tire, knowing the pressure and contact patch. I know of a high school science teacher that slipped sheets of paper under the front, rear and sides of a tire to enable measuring the tire contact patch to come up with the weight on the tire as stated. Force (weight) = pressure x area.
I have done this many years ago and it DOES "work" to a certain point.
It will get you in the ball park of how much weight is "resting" on the ground UNDER the tire.
The key to accuracy is getting accurate measurements of the actual contact area.. It also requires tires on concrete or asphalt so you can get the sheets of paper snugly against the tire without interference from dirt, rock or gravel.
Then you have to make sure the paper is SQUARE to the tire, any out of square measurements will affect the result..
I did this on a pickup truck and the overall weight I measured was within 100 lbs of the door sticker unladen weight. Not bad for a truck weighing 5500lbs!
