Balancing Tires

[charbaby]

Im going to take in my new GoodYear Assurance Comfort Treads and have them installed on my factory aluminum wheels. The Integrity's that they will be replacing will be thrown away. The GYACT's each have a RED DOT on one sidewall. Can someone please tell me just how these dots should line up and with what? I have heard that the red dots should line up with the valve stem which means that the dot should be placed on the outside of the wheel right at the valve stem, not on the inside? I've never had anyone explain this to me. What if the dot IS on the inside of the rim? I'am looking for the best ballance possible considering just how many people that I read about that are unhappy with their tires after instalation due to viberations and shimmy on the road. Please educate me before I have my new tires installed.

 

[mrsilv04]

A quick google search found this article from "Modern Tire Dealer".

A yellow dot is supposed to be lined up with the valve stem.

http://www.moderntiredealer.com/t_inside.cfm?action=performancehb_det&storyid=1195&pgNum=3

"If the tire features a red dot on its sidewall, this dot indicates the tire´s point of maximum runout or maximum force variation. Mount the tire onto the wheel to align this red dot to the wheel´s low runout point (this may be marked with a color dot or with a small notch. If in doubt, check the wheel maker´s instructions, or physically measure wheel runout to find the low spot)."

 

[Kestas]

There's no hard and fast rule for yellow and red dots. This has not been uniformly standardized in the tire industry. You have to query the specific manufacturer for the meaning of the markings.

 

[charbaby]

mrsilv04,
Thanks! That's some really good reading. I wonder just how much I'll have to pay someone to balance my wheels the perfect way.LOL! Those dots really do mean something!

 

[alreadygone]

Poor ole CapriRacer's explained this here so many times I'll not be suprised if he lets this one slide!

Bob

 

[mrsilv04]

Originally Posted By: Char Baby
mrsilv04,
Thanks! That's some really good reading. I wonder just how much I'll have to pay someone to balance my wheels the perfect way.LOL! Those dots really do mean something!


The only one that I really care about the balancing on is the motorcycle. The guy that does mine checks the balance on the bare rim as well.

When it comes to the truck and cars, mediocre is fine.

 

[gtx510]

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=17

 

[Kestas]

Some old discussion about marks on tires.

http://www.bobistheoilguy.com/forums/ubb...rue#Post1081735

 

[ewetho]

This is how to be anal about it.

If you want the balancing the best it can be then have them installed the smae way on each rim (Say dot codes in or out) unless you get directional tires (comfort treads are not). Then have them verified for proper assembly and correct balance on Hunter 9700 Road Force Balance machine. If any road force is over 18 lbs 0r .018" then have them match mount the tire to the rim. If the rim is bad replace it if the tire is do not accept this. Sure the machine will say 25 lbs but not good enough. Make sure they make the high spot of road force. Then have them balanced dynamically (inside and outside weights). Now once this is done any wheel over say 10 lbs have them put this make down and thread the lugnuts on fully by hand. You can fully tighten any wheel not over 10 lbs of road force now. Then set the car down on all 4 wheels and then tighten the wheels to spec. This last step will take up to an additional 10 lbs of roadforce out of the wheel. Now it should be smooth as it gets.

Provided not visual lateral runout is in the tire which can lead to steering wheel nibble, but will not show up on the Hunter machine. You have to visibly verify this.

I send tires back for this whenever I run across it. NO GOOD!!!

 

[Cogito]

I've never heard of this "runout" concept before. When should you be concerned about it? What does it really mean?

 

[CapriRacer]

Originally Posted By: Cogito
I've never heard of this "runout" concept before. When should you be concerned about it? What does it really mean?



First: What is it? Think "out of round" and you'll be really close.

When to be concerned?

2 times:

1) If you have a vibration that can't be fixed by dynamic balancing

2) If you are anal retentive.

 

[ewetho]

Out of round is a good thought. But actually it is the LOADED variation. So the maximum road force may not be the high spot (Most of the time it is but not always). You may have a tire that is round but stiffer on one side then the other.

When I had the machine I would ALWAYS at least do the quick check. It did not check for pulls (variation in stiffness of each tire when at pressure) but at least checked for abnormal tires.

When to be concerned Capri Races has it right. I have seen it also crop up as steering wheel nibble (oscillations).

The bad day is when you have to do the above just to settle down a vehicle.

 

[Cogito]

Originally Posted By: CapriRacer
1) If you have a vibration that can't be fixed by dynamic balancing

How often does this come up? I can't say as I've ever encountered this situation.

 

[CapriRacer]

Originally Posted By: Cogito
How often does this come up? I can't say as I've ever encountered this situation.


Well, I guess I have to consider you're in Chicago.

But if you lived in Florida, you would have encountered this, so keep in mind there are some pretty large differences between parts of the country - BUT

I'm guessing that static balancing takes care of 50 to 60% of the problem, dynamic balancing takes care of an additonal 15 to 20%, and match mounting takes care of about 10% to 15%, and the rest is something else (if I did the math, this would be 5% to 25%, but I think the 25% is way too high - more like 10%.)

 

[ewetho]

Not too often that it become a real issue but the newer stuff is getting more finicky and the larger wheels and tires are not helping. As a 2% (arbitrary number to make a point) error on a 15" tire is Ok but a 2% error on a 20" is like 40 lbs of road force at speed and is a big problem.

Have seen tires go bad as well and when I had a the Hunter 9700 at my last shop I would always do the quick check just to make sure I did not get a BAD TIRE.

 

[Ken2]

Especially with Goodyears, look at eccentricity...egg shaped tires. It took seven Assurance Triple Treds to find four round enough to run smoothly.