[vex]

Starting early are we, lets see if you address any of the points I've raised thus far.

(for review)

And completely negates the speed rating of the tire. Sidewall deformation caused by stretching not only results in premature tire failure, but also eliminates the speed rating as viable metric to ensure safety of the car.

Stretching the tire really has no benefit beyond aesthetics (but last I checked cars were meant to be driven).

On the contrary, see the above quotes from installers and individuals in the business. Even if they tell you it's bad and you insist upon it being mounted, and a family dies because you used your predictable vehicle behavior to slam into them, who's going to take the heat for all those who died? You? Or are you going to let the buck go to the individual that broke the law in mounting your tire?

Do you really want me to get the information I already posted from a tire designer to prove you have altered the tire dynamics to no benefit?

Just out of curiousity as the geometry is deformed, tire pressure is altered (maximum tire pressure--do you still put in the recommended amount, are you eyeballing it, or some other means outside of manufacturers spec)?--With due respect, you answered this by stating you eyeballed it.

Furthermore stretching tires can run aground upon other design features such as Michelin's Stress Equilibrium Casings

What do you mean by technical data? How much tire defelction is altered during a specific corner? Would you like it arranged by contact patch size, wheel size, or some other metric? You seem to demand specifics but be purpously obtuse when it comes to defining the metrics.

Would you like to see acceleration data, lap times, or some other metric? If you have an idea of what you want, I'm sure I can hunt it down for everyone to see. Beyond what I have already posted, what specifically do you have issue with? Is something stated that is not accurate or correct? If so, what is it and why?

Then you dictated that I was belittling you. In all honesty I'm still waiting on those answers from page 3. Care to elaborate?

back to that list:

What data do you want? Do you want the proper PSI for tire inflation with modified geometry, or would you like something else?

Actually I have never heard of a properly mounted and inflated tire ever breaking the bead without a structural defect manifesting itself. But since this is your allegation, find me a documented incident where one such occurred.

Which begs the question, how do you gage proper inflation when you deform the sidewall that much? You do not fill it to factory spec. What metric do you use to fill it or are you just filling it 'till it's "that'll do?" For all you have shown, you could be driving with it under inflated or over inflated and you wouldn't know would you? You're guessing on something that you have no data on. If you have data on proper pressure filling on deformed sidewall tires then I suggest you enlighten us on how the tensile strength of the sidewall is accounted for.

The list goes on and on, but you have yet to address those, so I'll leave it there for now.

Originally Posted by sofaking

This was my argument all along. Your conveluted subject changes and misdirection while pulling apart each sentence without reading the point of the post is what caused the argument. Notice how the original posts say that it WILL lead to failure (certainty) and this one said it CAN lead to failure (possibility).

Are you telling me there's tires that will not fail? Obviously not, so it still stands that all tires fail (certainty), as you have stated stretching a tire decreases the time or life of the failure, no? So back to what I said originally; Stretching a tire beyond manufacturers spec can and will cause it to fail. Do you know when or for that matter, if you're encroaching upon the plastic region of deformation of the compound? I've given you a simple test to verify if your specific stretch does, but you refuse to run the simple test that will give you the answer you're looking for. That's your issue. Not ours.

Without the math niether of us can be certain.

Actually, you don't need math to be certain. You need to understand the science to be certain, otherwise you will always wonder: "Did he just BS me, or did he just pull some number from somewhere?" So in all honesty would you be certain?

But if it doesn't lead to failure I'm not sure how it's reasonable to argue it's unsafe.The failure rate of anything is 100% on a long enough timeline.

Thank you for agreeing with me. Is a stretched tire going to fail before or after a properly mounted tire if they undergo the same driving conditions? How about if they hit a pot hole at speed, will they both have the same lifetime?

If we don't define when its going to happen then to argue the safety of it is pointless.

Yes because you don't know when you're going to crash into a wall during a circuit so lets not worry about safety. I mean, seat belts, harnesses , helmets, barriers, they don't stop failure or for that matter know when failure will occur we must not need them. Again, logical fallacy to argue this point.

Also for clarification, the whole science arguement that started wasn't by me. You felt the need to justify what you were saying by trying to bury me in science that I clearly didn't go to school for. I understand basic concepts of physics and how they apply in the world.

Oh... you didn't say:

You're dealing with concepts not application, that's theory.

What we've been discussing, and have been for ages is Material Science (which is an applied science, not theoretical). Your statements have been to the effect that unless I generate some random number everything I'm attempting to show you in science is just theory. Unfortunately I'm not that gullible, nor are a majority of the individuals on this board. Now continuing with your post...

I never argued that you weren't scientifically acurate to say that it's weaker, I only argued that nothing definitive about the safety concerns can be determined from the information except the single thing defined (weakness).

Do you remember that little post about elastic and plastic deformation? By weaker, it means you have removed tensile strength from the tire. This translates to a closer proximity on the stress-strain curve to the yield (where plastic deformation begins), and thereby closer to the ultimate yield (where you have catastrophic failure). More to the point, as soon as you encroach upon the plastic region the tire is considered failed (in polymers it's whenever necking occurs in a test sample). Hence, weaker is not some arbitrary term you seem to think it is. It is scientific. It has value.

I don't feel a need to continue with you picking apart every word I say, but I would like some clarification in acceleration not being a force.

Be happy to oblige.

Acceleration changes the tire speed in relation to the ground, the direction of the tire (from a stop), and the shape of the tire through centrifugal force and friction with the pavement. Can you clarify why acceleration would not be a force?

Acceleration, by itself, is not a force. If you look at the units of acceleration they are in terms of length per second per second (or second squared). Inertial forces can be derived by using acceleration, but must by definition be coupled with mass.

I'm sure you would break it down into different factors of acceleration, but as a broader term why would it not be right?

Lets look at a very simple problem. Take a particle of finite mass traveling through space at a constant velocity (a=0). We now wish that particle to travel in some other direction. We therefore impart a force upon the body. At time=0 acceleration is still naught, though the force is applied, the change in direction has not occurred. As time progresses acceleration increases so long as that force is still applied (or in otherwords you have a constant force [lbs] causing an increase in acceleration [ft/s^2] over time)

It doesn't look as simple as placing it in Newton's second law because there are variables to rotation, but it still seems to apply to the description.

Acceleration is a derivative (as in derived from, not the mathematical operation, though it is that as well) of the forces. For instance; you will not apply an acceleration to a tire to get it to move. You can understand that the tire is accelerating, but the acceleration itself is not the cause. Using one of the previously discussed terms torque; the tire has a torque acting on the center of the hub. In other words you have a force acting through a moment arm which is then resulted into the tires acceleration.

I would think that if acceleration isn't a force then braking (the removal of rotation) would not be a force.

If you were using braking as a form of acceleration it would fall under the same as acceleration. I was personally using braking as another metric of force being applied to the brakes via friction which would impart a torque on the hub.

Can you clarify please with a concise thought instead of breaking down each sentence?

Nope. But hopefully that helped.