Words and Photography by Bryan Grant
Header photo by Robb Cox
Diagrams courtesy of Bridgestone Australia

Page 1 | Page 2 | Page 3 | Page 4

ROTATION

Different forces are placed on each tyre depending on the corner it is on. This means that each tyre will have its own wear pattern. If this goes unchanged (by not rotating tyres frequently), then it may render the tread un-roadworthy long before it should. By rotating tyres at regular intervals, you spread the differing wear patterns out over all four tyres, and the result is a much longer tyre-life expectancy.

Non-directional tyres (those that can run either direction) should be rotated at 10,000km intervals minimum. Refer to the diagrams for the correct rotation pattern depending on your vehicle’s 4WD system and based on your tyres being non-directional. Directional tyres that can only go on the one side of the vehicle should be rotated front to rear.

ALIGNMENT AND BALANCE

Moving away from the tyre’s own influence on wear, we come to the vehicle side of things and find another way of driving your rubber further. After pressure and rotation, alignment is the next big factor in determining how even your tyres wear.

A wheel alignment is the process involved in making sure all your tyres are pointing in the right direction. The biggest giveaway that your alignment is out, is a wear pattern on the tread that is biased to one side more than the other due to incorrect camber (see the camber contact diagram to see how it influences offset tyre wear). In some cases, the vehicle may pull to one side or not willingly travel in a straight line.

Ideally, once you have your wheels aligned professionally, it would be safe to assume that they will stay that way. However, due to the very nature of off-roading, this is not always the case. If you hit one of your front wheels with too much force, be it a rock in the scrub or a gutter on the road, it pays to get your alignment checked.

Even if your wheels are aligned, an unbalanced tyre produces vibration as it rotates and is easily recognised by the driver. Wheel balance is more important to driver comfort than tyre wear, though a severely out of balance wheel can ‘shake’ an abnormal wear pattern into the tread as it wobbles.

There are two reasons a previously balanced wheel will start vibrating. The most simple and common is when the wheel weights become dislodged, and the other is due to tyre wear. As the tread level decreases, the reduction in rubber from the tread blocks reduces the wheel’s overall weight. This may cause the weight distribution to change and hence create an unbalanced wheel.

MONEY-SAVING CHECKLIST

• Check tyre pressures weekly using a quality gauge. Pressures should be checked on cold tyres
• Avoid excessive acceleration and speed to lower fuel-usage costs along with tyre wear. Avoiding high-speed braking where possible will also prevent tyre wear dramatically
• Rotate your tyres at no greater than 10,000km intervals to increase tyre service life and to negate heel and toe wear
• Have a wheel alignment performed if you can’t remember when it was done last, when new tyres are fitted, or if you hit an object with considerable force