Tips on tire balancing

When a tire is installed on a wheel rim, it is usually followed by a balancing process. Have you ever wondered why?

The purpose of the balancing

The purpose of the balancing is to eliminate any vibration which might be caused by any mis-match between a tire and the wheel. First, you may wonder why there might even exist a mis-match requiring tire balancing when you're buying new tires and possibly installing them on new wheels or even used ones which are in good condition.

To begin, it is important to realize that the amount of weight difference which could cause vibration can be extremely small. Most tire balancing machines today are set to detect and correct vibration caused by as little as 1/4 ounce. Just 1/4 ounce ... that's less than the weight of the pat of butter you put on your morning toast!

Why this tiny weight can be important is based on the principle that a small force, repeated rapidly and frequently can cause serious damage to almost anything. Remember how just one tiny drop of water, dripping on a piece of solid rock over hundreds of years can wear that rock forming fantastic shapes and formations which we marvel at in nature. Next take into account that 1/4 oz. (which is the minimum a tire balancing machine corrects) is many times heavier than that tiny drop of water which can wear away a mountain and you can start to realize that this small weight imbalance can be important. Now add to this, the knowledge that a car's wheel which is traveling at 60 mph is making approximately 4 revolutions every second, and every one of those revolutions is producing a tiny shake which is passed on to every part of the vehicle connected to it.

More than 14,000 little shakes an hour

This means that in just one hour driving, one wheel can deliver more than 14,000 of these little shakes. Now start adding the other wheels on the car, multiply by hundreds of miles driven in a day and then start factoring-in the holes, bumps, rocks, debris, and other things a car may encounter on the road and you can see that the numbers start growing to incredible proportions. It's not necessary to calculate all the thousands or even millions of vibrations which a vehicle could experience, because the exact number isn't important. What is important is simply to be aware that what might -at first glance- seem to be a very tiny, insignificant event, can easily become something of importance once you take into account the tremendous number of times this event is repeated in a vehicle which is being used under ordinary driving conditions.

When should balancing be performed?

People often notice unbalanced tires when they are on the front wheels because the vibrations are transferred through the steering wheel to the driver's hands. These same vibrations are not felt when they are on the rear wheels, but the fact that the driver isn't aware of them, doesn't mean they aren't affecting the mechanical wear-and-tear of the vehicle. This is why it has become a standard practice to balance every new tire at the moment it is installed, regardless of which position it will occupy on the vehicle.

How often should tire balancing be checked?

This can best be answered by simply remembering the thousands of revolutions which most tires make every day in simple driving conditions. Now take into the account that every road is not perfect and may have cracks, holes, rocks, glass, many kinds of other hard and sharp debris, all of which can come into fast and frequent contact with the tire as it is driven. Each one of these tiny contacts in themselves may not make any significant difference in the wear and life of the tire, but again these events are repeated thousands of times a day, over and over.

The result: the tires wear, but not only that, because the contacts with foreign objects are not usually in any regular orderly sequence, the tires will probably wear unevenly. Very gradually this uneven wearing of the tire changes the balanced condition which was established when the tire was installed. It is not likely that the change will become noticeable very suddenly unless there has been some unusual impact or extremely harsh road conditions. However, if a tire is tested after it has been used for a few months or after 1,000 to 2,000 miles of driving, it is not at all unusual that there has been a sufficient change to make a detectable difference.

Obviously the ideal would be to have your tires balanced every day you start out just as it would be great to change the oil, lubricate, wash and polish and do other types of up-keep and maintenance but in real life this isn't practical. Under average driving conditions, experience of many thousands of motorists has shown that it is advisable to check the balance on tires every time they are being rotated (between 4 and 6,000 miles) and certainly any time it becomes necessary to make a repair to the tire because of a puncture.

The conclusion?

Tire balancing is important to keeping your vehicle in good mechanical condition. If it is only attended to when there is a noticeable vibration in the ride or is felt via the steering wheel, it may have already caused considerable stress on your vehicle.

Always balance new tires when they are installed
Check tires for proper balance whenever tire rotation is performed at intervals of 4,000 to 6,000 miles.
Have any tire which is repaired, balanced again to compensate for the weight change produced by the patch and the damage being fixed.

Also, you might find some other useful material in our consumer information page

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