A wheel and tyre look perfectly even, but no manufactured part is exactly uniform. There is always a slightly heavier spot somewhere around the assembly, and at speed that tiny imbalance turns into a vibration. Balancing is how it is cancelled out.
What it is
Wheel balancing corrects the distribution of weight around a wheel-and-tyre assembly so it spins smoothly. A balancing machine spins the wheel, detects where the heavy spot is and how big it is, and the fitter adds small balance weights to the rim, clipped onto the edge or stuck to the inside, to counter it. With the heavy spot cancelled, the wheel turns true at any speed.
The amounts are small, often just a few grams, but at motorway speed a wheel spins around 15 times a second, and an unbalanced few grams becomes a noticeable shake.
Not the same as alignment
The job most often confused with balancing is wheel alignment, and they are completely separate:
- Balancing sorts the weight of the wheel and tyre, so it spins without vibration
- Alignment sets the angles the wheels point at, so the car drives straight and the tyres wear evenly
A car can need one, the other, or both. A vibration points to balance; pulling to one side or one-sided tyre wear points to alignment.
When it is needed
Balancing comes up in a few situations:
- Whenever a new tyre is fitted: the wheel and tyre are a fresh pairing and need balancing as standard, so it is done as part of the job when new tyres go on, including a set bought from a tyre retailer like Tyres.co.uk and fitted locally
- When a vibration appears: the most common reason on existing tyres, covered in the signs a wheel needs balancing
- After losing a weight: they can be knocked off by a kerb or a wheel scrub
- After a hard pothole: a heavy strike can shift things enough to upset the balance
Why it matters
An out-of-balance wheel does more than feel rough. The constant vibration:
- Wears the tyre in patchy, cupped patterns that shorten its life
- Adds strain to wheel bearings, steering and suspension
- Makes the car tiring to drive at the speeds where it shows
None of it is dangerous on its own, but left alone it costs in tyres and wear elsewhere, which is why balancing is treated as routine rather than optional. There are also two depths of balancing, static and dynamic, that correct different kinds of imbalance.
From the workshop: people often live with a steering wobble for months thinking it's the road or the alignment. Nine times in ten it's a wheel that's lost a weight or never balanced right after a tyre change. Five minutes on the balancer and it's gone.
Sources and accuracy. The description of balancing and when it is needed reflects standard industry practice at the time of writing. If anything here looks wrong, get in touch and we will check it and put it right.
Common questions
What is wheel balancing?+
Correcting small differences in weight around a wheel-and-tyre assembly so it spins evenly at speed. A machine spins the wheel, finds any heavy spot, and small weights are added to the rim to cancel it out, removing vibration.
Is wheel balancing the same as alignment?+
No. Balancing corrects the weight distribution of the wheel and tyre so it spins smoothly. Alignment sets the angles the wheels point at so the car tracks straight and tyres wear evenly. They are different jobs that are sometimes confused.
When do tyres need balancing?+
Always when a new tyre is fitted, because the wheel and tyre are a fresh combination. After that, balancing is needed if a vibration develops, if a balance weight is lost, or after a hard pothole strike that could have shifted things.
How long does wheel balancing take?+
Only a few minutes per wheel on a modern balancer. It is usually included in the price of fitting a new tyre, and as a standalone job on existing tyres it is quick and inexpensive.