Balancing tyres

The goal of tyre balance is to distribute weight equally around the entire circumference of the tyre. Wheels that are out-of-balance can cause uncomfortable vibrations while driving. It also results in premature wear of suspension and steering components, rotating parts, and tyres.

When refitting any tyre to a wheel, Continental recommends that the tyre is correctly rebalanced to help eliminate vibration and avoid premature wear caused by an imbalance in the rotating wheel and tyre assembly.

As part of routine vehicle maintenance, drivers should seek to balance the tyres on their vehicle after every 5,000-10,000 km travelled, or after 1-2 years (whichever comes first).

Also, it's worth balancing the tyres and wheels when:

• Buying new tyres, rims, or wheels;
• Rotating the tyres;
• Repairing the tyres;
• The car hits a large pothole.

Another thing to remember; tyre balance is entirely different to wheel alignment, though the two concepts are sometimes confused. Aligning a set of wheels entails adjusting their angles so that they're parallel to each other and perpendicular to the ground.

Knowing the signs of imbalance

Tyre imbalance can develop over time as the tyre tread wears down through regular use and the distribution of weight changes. But subjecting the tyres to excessive stress by driving on poor roads, hard braking and cornering may hasten matters further.

When one or more tyres are out-of-balance on your vehicle, there are several common indicators:

• The car experiences vibration at high speeds;
• There's uneven wear on the tread;
• There's an increase in fuel consumption;
• There are issues with the suspension.

If you notice one or more of these symptoms – even if the tyres are relatively new – then it's possible your car has an imbalanced tyre.

How are tyres balanced?

There are two methods for tyre balancing performed at your local garage; static balance and dynamic balance.

1. Static balancing

If there is only a slight imbalance to the tyre, static balancing is the appropriate technique and is relatively easy to do; the wheel and tyre assembly is placed onto a vertical supporting device with a spindle or equivalent to measure balancing on one axis. The heavier side will lean lower to the ground than the lighter side; once identified, the mechanic will place a small weight measuring fractions of an ounce 180 degrees across the plane of the tyre, onto the flange of the wheel rim, until the balance is restored.

2. Dynamic balancing

For more complex cases of tyre imbalance, dynamic balancing is a technique using spinning computer balancers to measure the tyre on all three axes. The mechanic places a fully assembled wheel and tyre on a machine and rotates it at speed ranging from 16-25 km/h to 88-96 km/h. As it spins, the sensors of the machine capture every single weight imperfection.

With the analysis complete, the computer then specifies how much weight and where the mechanic should apply to balance the tyre. The small weights – either clip-on or adhesive weights – are added to both the inner and outer sides of the wheel rim, to provide the highest precision and balance.