What affects the quality of wheel balancing

Equipment or the human factor?

What has more effect on the outcome of wheel balancing, the balancing machine or the fitter’s skill? On the whole, both matter in roughly equal measure. Experienced tyre fitters say that you can balance anything “down to zero”, but that alone does not mean the wheel will be fit to use safely for its purpose.

While you can at least judge a fitter’s skill (and attitude to the job) from indirect signs, you sadly cannot judge the accuracy and condition (calibration) of the balancing machine at all. So try to avoid having your wheels balanced at unfamiliar “roadside” tyre-repair shops: you will end up having that balancing checked again later anyway.

So what should good-quality wheel balancing look like?

1. There is no point balancing a dirty wheel, with lumps of dirt stuck to the inner surfaces of the wheel and stones wedged in the tread, so at a good tyre fitter’s the wheel is thoroughly cleaned of dirt and stones, and of any previously fitted balance weights, before balancing.
2. Before balancing it is well worth measuring (and not “by eye”, but exact figures) the runout of the wheel and the tyre (radial and lateral).
3. A balancing machine will not show any accurate measurements at all if it is coated in a thick layer of dirt.

Not so long ago, fundamentally new machines started appearing at modern tyre centres, popularly known as 3D tyre fitting. This equipment uses laser diagnostics to work out the precise geometry of the wheel on its own and of the complete wheel assembly (runout included), and to position the tyre on the wheel in the most effective way, giving the best possible mutual compensation between the wheel’s and the tyre’s imbalance. This kind of equipment is undoubtedly a serious step forward for wheel balancing, but for now, sadly, it remains extremely hard to find at tyre centres, even in big cities.