Wheel balancing

Out-of-balance tyres are bad news: they wear out your tyre tread and drive down your fuel economy. You’ll most likely be tipped off to this problem by vibrations in the steering wheel, the seats, vehicle chassis or by patchy or cupped wear on your tyre tread. This article tells you why tyres become unbalanced, how to recognise out-of-balance tyres and what to do to fix the problems.

Wheels are unbalanced when their weight is distributed unevenly around their circumference or are no longer perfectly round. Even deviations of less than 10g can cause an imbalance. They can also be due to uneven wear on a tyre, a dent in a rim or loss of a weight that was previously added to balance the tyre.

The most immediate consequence of driving on out-of-balance wheels is accelerated tread wear. There can be a number of root causes of tread wear but balance problems cause a signature pattern of patchy wear or cupping (dips in the tread that span the tyre laterally). If not dealt with, this wear can rub years off your tyres’ lives.

Another potential effect of driving on unbalanced wheels is damage to your bearings or suspension components. Unbalanced wheels tend to bounce up and down, putting extra strain on the components and potentially setting you up for very costly repairs.

The effects of unbalanced wheels in the form of additional vibrations as you move down the highway can make the vehicle uncomfortable and in extreme cases even unsafe.

Mechanics remove your wheel and tyre assembly and use a balancing machine to identify lighter or heavier spots on the wheel or tyre by measuring vibrations. They then add small weights to the rim to balance the wheel assembly. Sometimes they rotate the tyre’s position on the rim (while the rim itself remains stationary). This is especially useful when there are heavier spots on both the rim and tyre that line up and need to be offset.

All wheel assemblies need to be balanced when fitting new tyres. If you notice any of the signs of imbalanced tyres covered earlier in this article, you should have your wheels checked and balanced immediately. However, balancing should also be incorporated into your vehicle maintenance routine. Check for balancing issues when rotating your tyres or having your vehicle wheel aligned. Ideally you should not go more than two years without re-balancing your tyre-wheel unit and if you drive on rough roads, it would be advisable to check on a yearly basis.

Although the aim of tyre rotation and balancing is the same—to protect the tyre’s tread and extend its life—these are two different processes. One difference is that tyre rotation is something that you can do by yourself if you choose to and have the right equipment, as it is a relatively simple process that involves removing the tyre and wheel units and changing their position on the vehicle according to the pattern described in your user’s manual. Balancing, as described above in this article, is a more complex process that requires pricy equipment and professional expertise. Tyre service shops often pair these two services.

Tyre balancing and wheel alignment also often go hand-in-hand, and once again, they are both meant to preserve the tyre’s lifespan by preventing excessive friction between the road and tyre tread. When performing an alignment, a mechanic makes adjustments to the suspension system to make sure that the angle between the tyre and road surface is correct. Like balancing tyres, aligning wheels requires specialised equipment and knowledge, and isn’t something that you can easily do on your own.

If you notice signs of unbalanced wheels or need another tyre maintenance service, get in touch with your nearest tyre dealer.