Mini Van Pulls to the Right

[kaisen]

If I recall correctly, some tires are marked inside/outside even though they are not directional tread pattern. Cosmetics of the sidewall, sidewall protectors, even multi-compound for inside/outside tread blocks. I certainly may be wrong.

But I think having tires that are engineered to compensate for pull sounds like hooey.

E

[tabascobobcat]

Originally posted by kaisen


But I think having tires that are engineered to compensate for pull sounds like hooey.

E

ya...only the bad ones

You sound pretty confident. Have you ever made a tire or been in a facility that does ?? Just curious.

You are focused on the wrong part of the tire. The internals of the carcass probably influence the Residual Cornering Force, Residual Aligning Torque, Conicity, 2nd and 3rd harmonic both longitudinal and tangential than does the tread type and pattern. Heck, even the side wall construction has more influence than does the outer tread. All facilities actually have to hand grind the tread as a final process to make the things appear round.
Now back to helping someone with and issue......

Any info regarding the vehicle lean ??

[tcar]

Originally posted by kaisen
If I recall correctly, some tires are marked inside/outside even though they are not directional tread pattern. Cosmetics of the sidewall, sidewall protectors, even multi-compound for inside/outside tread blocks. I certainly may be wrong.

E

Exactly, and those tires can rotate either direction, just make sure the 'outside' is outside.

[kaisen]

Originally posted by tabascobobcat
You sound pretty confident. Have you ever made a tire or been in a facility that does ?? Just curious.

You are focused on the wrong part of the tire. The internals of the carcass probably influence the Residual Cornering Force, Residual Aligning Torque, Conicity, 2nd and 3rd harmonic both longitudinal and tangential than does the tread type and pattern. Heck, even the side wall construction has more influence than does the outer tread.

No I've never made a tire, but perhaps you have ..... Akron, OH is the tire capital of America, isn't it?

I have visited a tire plant, and knew people who used to work for BFG/Uniroyal. But that plant closed several years ago.

Thanks for the info. I mentioned I was perhaps uninformed. Unidirectional 'tread' doesn't mean the tire isn't directional. I gotcha.

Still, I can't quite get my head around why a tire manufacturer wouldn't make the tire 'square' as it appears to camber.

E

[tabascobobcat]

I may just be in the little bit of knowledge is dangerous area here. The many parts/components of the tire are molded together with the rubber that we actuallyy see with a 3 part mold, 120 degrees each, so it is actually more triangular than it is square. Difficult to maintain and even pressure across the three molds at the same time. Hence the 3rd harmonic properties. Goodyear let me do this once to try to gain an appreciation on how difficult it is for them to control the various parameters involved.

[tabascobobcat]

[tabascobobcat]

I did follow up with the smart guys at work today.
Yes, the tires are designed to compensate for the road crown, both in the States and the others Right hand drivers. It is our understanding that most, if not all tire companies now do this.

I did get a better and more detailed explanation of how the different forces generated in the tires accomplish this, but I won't bore the board with the details. PM me if you wish a more detailed explanation. Whether a tire is on the left side or Right side of the car, the PRCF is always pushing toward the left side of the car.
So, theoretically a car in the US should go straight on a two-lane highway with 1 to 2% of Right road crown. That's in a perfect world with no production variation.

I also now have a better understanding of how these same forces can cause the pull in one direction or another. Please try swapping just the LF and RF and let us know the result. Good luck.

[Brother]

I will when I get a chance. Probably saturday.

[Brother]

Swapped tires and drove a little. Seems a little better. The left front tire was way off level when I put one on there. I'll keep you posted.

[tabascobobcat]

What brand of tire ??
Just curious.
Off level.....how much ??
Again, just curious.

[Brother]

uniroyal

considerably. other tire was perfect.

[Brother]

both of the front tires were put on by the dealer I bought it from about 5,000 miles ago. I did have the car aligned a few weeks ago. it pulled less after the alignment mostly because one side was at about -1 degree of camber.

I just set a small level across the two tires when they standing up on my garage floor. Level with what used to be the right front and well off with the other tire.

[Brother]

Well after a week. It is much better after swapping the front tires. maybe they were messed up a little from riding on a bad alignment. I don't pretend to know.

[tabascobobcat]

Good news.