Anyone here a mechanical engineer

[Big Dad]

My question is ,

On a bead of a racing tire like a racing slick for example ..

How many lbs of air pressure is holding the tire to the bead ?

For arguement sake, lets say the tire is 14 x 32 x 15 circ is 100 inches and it runs at 9 lbs psi

Anyone here a math expert to help me figure it out ?

[idrivea4banger]

Only on the weekends.

[Nash B.]

I'm no mechanical engineer, but it looks an awful lot like 9 PSI.

[GE]

The answer is 42.

[Big Dad]

Maybe a better way to word the question is how many lbs of force is holding the tire against the bead ?

[93bluelx]

Maybe a better way to word the question is how many lbs of force is holding the tire against the bead ?

well if the square root of 69 is ate something, then it must be 3

[Nash B.]

Maybe a better way to word the question is how many lbs of force is holding the tire against the bead ?

About 9 pounds per square inch of contact area?

[Silverback]

aren't there two forces holding the bead on. One being any pressure in the tire, and a second being the seal made from the tire to the rim, where the inner diameter of the rim is slightly bigger than the inner diameter of the tire?

[Big Dad]

aren't there two forces holding the bead on. One being any pressure in the tire, and a second being the seal made from the tire to the rim, where the inner diameter of the rim is slightly bigger than the inner diameter of the tire?

Yes, I believe so ..

Hope someone can provide an answer

[Nash B.]

I think the volume of the tire comes into play ?

Why would it? Pressure is a ratio of force to surface area. Increasing the surface area while keeping the pressure at a constant would increase the total force but the pressure, the force to surface area, will remain the same.

LOL @ Camino is a dipshit.

[Big Dad]

I'm not sure one way or another , thats why I asked the question

Ps

I never tagged the topic

[TENGRAM]

Yes, I believe so ..

Hope someone can provide an answer

You're going to need to provide more info or find an engineer who is very familiar with tires. I have no clue how much deformation is present in a mounted tire, nor am I familiar with the modulus of elasticity of tire rubber (although I could probably find a good approximation).

If, on the other hand, you want to completely ignore the initial force of the tire on the rim (before aired up), then the answer is 9psi. To find the force holding the tire to the rim you'd multiply the pressure times the area of contact (roughly the width of the bead times the circumference of the bead itself).

[BP]

There are sensors available to measure the tire bead pressure if you really need to know. It's a combination of friction, elasticity and air pressure that keep a bead seated. All of those numbers are going to vary with temperature, load, air pressure, wheel type, finish and what kind of tire.

[Trick Pony]

You would need to know the area of the tire that is in contact with the bead as well as the coefficient of static friction for the particular compound of the tire on the rim.

[mustangguy289]

3 is the answer