How much tire balance weight?

[KLS]

Anybody know some specs for how much tire balance weight is OK, and how much weight is too much...tell them to put that tire on somebody else's truck?

DJ, if you read this, what are the readouts on the GSP9700, and how much tolerance is OK for runout, etc?


Ken

[DJ]

Originally posted by KLS
Anybody know some specs for how much tire balance weight is OK, and how much weight is too much...tell them to put that tire on somebody else's truck?

DJ, if you read this, what are the readouts on the GSP9700, and how much tolerance is OK for runout, etc?


Ken

The GSP9700 is two machines in one -- it is a conventional balancer, and it can measure, and help the user compensate for, the radial force variation of the tire.

As a dynamic balancer, the readouts are "conventional". It tells you how much weight to put on each side of the wheel and where on the rim to put them. It works with conventional clip-on weights as well as tape-on weights. It is extremely accurate at this. Usually, balancing to better than 1/4 ounce is a waste of time.

As a radial force balancer, it allows the user to measure the runout of the wheel and the loaded runout of the tire. It then instructs the user to match the "high spot" of the tire to the "low spot" of the wheel. This allows the imperfections of the wheel to compensate for the imperfections of the tire, thereby reducing the net radial force variation of the two. That's a bit oversimplified, but it's easy to understand.

I don't know what the "tolerances" are -- I've slept since I last used it. I remember that, generally speaking, a loaded radial force variation of 25 pounds or less is good. My Tundra rode smooth as glass with over 20 pounds at one wheel.

[RobXS]

From the tire and wheel manufactures point, there is no limit on the amount of weight as long as it will balance out and you don't get a vibration. Generally if you have a tire or a wheel with a heavy spot that requires more than 4 ounces you will not be able to balance it out because the weight will be spread around the lip. If you used tape weights on a positive offset wheel you could probably go up to 5.

The amount of weight really depends on the quality of tire and wheel. Steel wheels generally will be less true than an alloy. A bent wheel can be a nightmare to try to balance. As for tires, a high quality segment molded tire like a Michelin should require very little weight. A clam shell molded tire like a TSL Thornbird may take almost all the weight in the shop.

If you have a good wheels and good tires I would expect less than 3oz per side, but like I said, more may not be bad. The goal is a smooth ride.

What is equally as important to balancing is the way they roll. You should really get down close and watch them spin on the balancer. It is possible to zero the balance, but still have a tire that hops like a kid on a pogo stick. If the tech does us a lot of lube, the bead may not set properly. It will still balance out, but you will really feel it at 60mph.

[SATundra]

Very good thread and posts. I had wondered about this as well.

[DJ]

Originally posted by RobXS


...

Generally if you have a tire or a wheel with a heavy spot that requires more than 4 ounces you will not be able to balance it out because the weight will be spread around the lip.

...

All Hunter DSP balancers compensate for this. The machine knows that a heavier weight is spread around a part of the circumference of the wheel and so has less effect than it would if it were concentrated at a single point, and it knows exactly how much effect this has for each size weight. So, it computes the actual weight required to produce the desired effect.

Hunter DSP balancers also have a "split weight" feature that lets you apply two smaller weights spread apart instead of one bigger weight. This is often preferable to putting a big weight on because small weights tend to stay on the wheel better. Also, you might not have the required big weight but might have lots of smaller ones.

[RobXS]

You do not necessarily need the hunter balancer to determine that there is a heavy spot. An experience tech will pick up on through understanding of the equipment that they are using.

If the tire has an excessive heavy, spot something that you will see in lower quality tires usually from the lap splice and the wheel is close to perfect, there is virtually nothing you can do. Splitting the weights in an effort to counter balance is not a good way to go.

A bad tire or wheel is bad. Trying to compensate by putting bad tire opposite of a bad wheel in an effort to get a smooth ride is pointless.

Personally I am not impressed with the hunter balancers. It is heavy on show and little on practicality. It is way too over promoted as a solution to balancing problems. As far a balancing tires. It does just as good as any other balancer, but it has features that really are not necessary if you know what you are doing. This is typical of the direction that hunter is moving with their alignment equipment.

Hunter is quality stuff, but they design it so that anyone can use it. If you do not balance tires all day and are not familiar with what works and what doesn't when it comes to balancing. The GSP is the perfect machine. If you balance tires for a living, you do not need the extra glitz that comes with the GSP. The other benefit is that with a machine like that you can really impress your customers which is what it is all about.

[DJ]

You do not necessarily need the hunter balancer to determine that there is a heavy spot. An experience tech will pick up on through understanding of the equipment that they are using.

The idea is measure where that "heavy spot" is and how "heavy" it is, so you can counter it with balance weights. Hunter balancers do that extremely well.

...

Splitting the weights in an effort to counter balance is not a good way to go.

Splitting the weights is an excellent way of balancing a tire. It allows you to use smaller weights, which stay on the rim better than bigger weights and are easier to mount on the rim. The result is a tire and wheel that are balanced exactly as if single bigger weights were used.

If you are using "tape on weights", you can split them so they are hidden behind the spokes of the wheel. Some cusomers think that looks better.

A bad tire or wheel is bad. Trying to compensate by putting bad tire opposite of a bad wheel in an effort to get a smooth ride is pointless.

Every tire and wheel on every new vehicle is mounted this way at the factory. Mounting the "high spot" of a tire at the "low spot" of a wheel reduces the net radial force variation and makes the resulting tire/wheel roll much more smoothly. Been there, done that, and it works beautifully.

Personally I am not impressed with the hunter balancers. It is heavy on show and little on practicality. It is way too over promoted as a solution to balancing problems. As far a balancing tires. It does just as good as any other balancer, but it has features that really are not necessary if you know what you are doing. This is typical of the direction that hunter is moving with their alignment equipment.

Good tires seldom benefit from "road force balancing" because they seldom need it. My Michelin LTX M/S on my Tundra and Sequoia are very good and didn't need it. It cannot be done with "very good wheels", such as my Toyota OEM alloy wheels, because they have almost no runout -- if you have no wheel runout, you cannot use it to compensate for imperfect tires.

However, some tires are simply not round and/or not uniform. People buy them anyway because they don't know good tires from bad tires. How many times have we seen posts on this forum by people who bought tires because they like how they looked? Road force balancing can make these imperfect tires roll much more smoothly. Only the Hunter GSP9700 has the features that make this kind of balancing possible.

The features found in Hunter balancers and aligners are there for when they are needed. Sometimes they are needed, and they work beautifully. When they are not needed, they don't get in the user's way. Hunter balancers and aligners are high quality, durable machines that you can depend on to make a living with. That's what they are for.

Hunter is quality stuff, but they design it so that anyone can use it.

Is this a complaint? It sounds better every time I hear it.

If you do not balance tires all day and are not familiar with what works and what doesn't when it comes to balancing. The GSP is the perfect machine. If you balance tires for a living, you do not need the extra glitz that comes with the GSP. The other benefit is that with a machine like that you can really impress your customers which is what it is all about.

It's not about "impressing customers", it's about "curing vibrations". Sometimes that's easy, and sometimes it's not. The GSP9700 really is "the perfect machine" for this job.

[RobXS]

Every tire and wheel on every new vehicle is mounted this way at the factory.

You seem to contradict yourself with these statements.

It cannot be done with "very good wheels", such as my Toyota OEM alloy wheels, because they have almost no runout -- if you have no wheel runout, you cannot use it to compensate for imperfect tires.

Hunter is quality stuff, but they design it so that anyone can use it.

My point it that a person who relies on a piece of equipment will not have the proper experience and skill to understand what he is doing. I can get the exact same results, a smooth ride using either a traditional spin balancer or the gsp. There are also a lot of other things that I can notice during a balance that if I were not skilled, relying on a machine would not help.

Hunter markets this to low volume shops as a way to cure problems. They have problems balancing tires because they do not do very many and probably haven't had a lot of training. Most mechanics wouldn't give tire balancing a second thought. That is where they run into trouble.

I would never seek out a shop just because they had a piece of equipment. I absolutely wouldn't pay extra to have my tires balanced by it.

[DJ]

You seem to contradict yourself with these statements.

If a wheel has no runout, then it cannot compensate for any force variation in the tire. If a wheel has a little runout, then that runout can be used to compensate for a little force variation in the tire. If a wheel has a bit more runout, then that bit more runout can be used to compensate for a bit more force variation in the tire. And so on ...

Such compensation is not necessarily "perfect", because the wheel runout doesn't necessarily match the radial force variation. Such compensation reduces the net radial force variation of the assembly, the result of which is a tire/wheel assembly which rolls more smoothly down the road.

My Toyota OEM alloy wheels have only a very small amount of runout, about 0.003" or less, so they can compensate for only a very small amount of radial force variation in the tires. My Michelins are very good, so they don't need much compensation.

All vehicle assembly plants use tire mounting machines which use whatever wheel runout it present to compensate for whatever radial force variation is present in the tire mounted to that wheel. Again, such compensation is not perfect, but the net result is a tire/wheel assembly which rolls more smoothly down the road.

So, where is the contradiction?

My point it that a person who relies on a piece of equipment will not have the proper experience and skill to understand what he is doing.

I rely on equipment and I have the proper experience and skill to understand what I am doing.

I can get the exact same results, a smooth ride using either a traditional spin balancer or the gsp. There are also a lot of other things that I can notice during a balance that if I were not skilled, relying on a machine would not help.

So, please enlighten us. I have no doubt whatever that skill is a very good and desirable thing, but my curiousity is deeply aroused as to how you actually apply it.

If the problem is caused by a lot of radial force variation in the tire, yet the tire has no visual defects and appears to have little or no runout, how do you detect the cause of the problem and fix it using a conventional spin balancer, which cannot measure the radial force variation in the tire?

I have seen numerous tires that have no visual defects and have virtually no measurable runout when rotated without load on a balancer or a vehicle, but these same tires have a great deal of radial force variation when rotated in a loaded condition, such as on a GSP9700 or on a vehicle on the ground. If you can't measure it and can't see it, such as happens with such tires on a conventional spin balancer, how do you fix the problem?

Hunter markets this to low volume shops as a way to cure problems. They have problems balancing tires because they do not do very many and probably haven't had a lot of training. Most mechanics wouldn't give tire balancing a second thought. That is where they run into trouble.

Who found this out, and how did they find this out?

I would never seek out a shop just because they had a piece of equipment. I absolutely wouldn't pay extra to have my tires balanced by it.

Many people do and achieve very satisfactory results thereby. Would you have us believe that it is wrong or misguided for them to do so?