Balancing and alignment are two different jobs that people often mix up. Balancing fixes vibration by evening out the weight around a wheel and tyre; alignment fixes pulling and uneven wear by adjusting the angles the wheels sit at. New tyres always need balancing; alignment is a separate check. Get the two confused and you can end up paying for the wrong fix.
What wheel balancing does
No tyre and wheel combination is perfectly even in weight. Spun at speed, a small heavy spot causes vibration, usually felt through the steering wheel at certain speeds. A balancing machine spins the wheel, finds the heavy point, and small weights are clipped or stuck to the rim to cancel it out. Every new tyre we fit is balanced as standard, because it's what stops a fresh tyre vibrating and wearing unevenly.
What alignment does
Alignment sets the angles (toe, camber and caster) at which the wheels meet the road. Correct angles mean the car tracks straight and the tyres wear evenly across their width. It's a suspension adjustment rather than a wheel-and-tyre job, which is the key reason it's separate from balancing. Alignment is what you check after hitting a pothole or kerb, not balancing.
How to tell which you need
The symptom usually points straight to the fix. This quick reference covers the common ones:
| Symptom | Likely fix |
|---|---|
| Vibration at speed | Balancing |
| Car pulls to one side | Alignment |
| One-edge tyre wear | Alignment |
| Patchy/cupped wear | Balancing or suspension |
| Off-centre steering wheel | Alignment |
When to have them done
Balance whenever a tyre is fitted, or if you feel new vibration through the wheel. Check alignment after kerb or pothole impacts, or whenever you spot uneven wear. It's good practice to have alignment checked when you fit a new set of tyres too, so you're not wearing fresh rubber on angles that are already out. We balance every tyre we fit, at your location across London, the Home Counties and the Midlands from one base at Brent Cross, NW2, so you drive away smooth.
What happens if you ignore it
Ignoring a balance problem means living with vibration that gets worse as it shakes the suspension and steering components, and it can cause patchy "cupped" wear that ruins the tyre. Ignoring alignment is more expensive still: it can wear one edge of a tyre clean off in a few thousand miles, and it wastes fuel the whole time because the tyres are scrubbing rather than rolling. Both are cheap to put right and costly to leave, which is why it pays to act on the first sign. Correct fitting and balancing is part of the tyre-safety basics TyreSafe promotes.
How a wheel is balanced, step by step
Balancing takes a few minutes per wheel and happens off the car, on a machine that spins the wheel and tells the fitter where to put weight and how much. The process is the same whether it is done in a workshop or from the back of a van:
- Clean the wheel. Old weights are removed and any mud, ice or stuck-on grit inside the rim is cleared, because a lump of dried mud is itself an imbalance.
- Mount it on the balancer using a cone or adapter that centres it exactly as the hub would. A wheel mounted off-centre gives a false reading.
- Enter the wheel's dimensions (diameter, width and offset) so the machine knows where the weights will sit.
- Spin it. Sensors measure the forces as it turns and the machine reports the weight needed and its position, usually to the nearest five grams.
- Fit the weights. Clip-on weights go on the rim lip of a steel wheel; adhesive weights are stuck inside the barrel of an alloy so they stay hidden.
- Spin again to confirm it reads zero, or close to it, then refit the wheel and torque the nuts.
A mobile fitter carries a balancer in the van, so a tyre fitted at your home or work is balanced to the same standard as one fitted in a garage. It is worth asking any fitter to confirm balancing is included, because leaving it out is a false economy that shows up as a shake within the first few miles.
Static and dynamic balance
A wheel can be balanced in two planes, and modern machines correct both, which is why they put weights on the inside and outside of the rim rather than in one spot. The distinction explains why an old-fashioned bubble balance sometimes leaves a shake.
Static imbalance is a single heavy spot. Left alone it makes the wheel hop up and down as it turns. One weight opposite the heavy spot cures it.
Dynamic imbalance is a heavy spot on one side of the tyre and another on the opposite side, offset across its width. That makes the wheel wobble side to side even if it is statically balanced, and it is felt as a shimmy through the steering. Curing it needs weights on both the inner and outer planes of the rim.
Wider, low-profile tyres on big alloys are more sensitive to dynamic imbalance, which is why cars on 18-inch and larger wheels are quicker to show a vibration when a weight comes off.
Some balancers can also measure road-force variation, spinning the wheel against a roller to find a tyre that is stiff on one side, but that is a diagnostic step rather than routine.
Balanced but still vibrating? What else it can be
If a wheel balances to zero and the shake remains, the cause is something balancing cannot fix, and the speed at which it appears is the clue. Work through these before paying for a second balance:
- A buckled or bent rim. A pothole can put a wheel out of true without a visible dent. Look for the signs of a buckled alloy.
- Flat spots. A car left standing for weeks, or a tyre that skidded under heavy braking, can develop a flat patch that thumps at low speed. See flat spots on tyres.
- A tyre that is not round or has a separated belt. A bulge in the tread or a tyre that visibly wobbles on the balancer needs replacing, not balancing.
- Wheels not centred on the hub. Aftermarket alloys sometimes need spigot rings; without them the wheel can sit slightly off-centre even with the nuts tight.
- Warped brake discs. A shake that appears only under braking is the discs, not the wheels.
- Worn suspension or steering parts. Play in a ball joint, track rod end or wheel bearing lets a perfectly balanced wheel move, and it is an MOT item, see the DVSA inspection manual on GOV.UK.
Our guide to steering wheel vibration causes works through these by symptom. As a rule, a vibration that changes with road speed is wheels or tyres; one that changes with engine speed is something else entirely.
What an alignment check involves
An alignment check measures the angles of each wheel against the manufacturer's figures and shows you a before-and-after printout, which is the thing to ask for. It is a separate job from balancing and needs different equipment. Alignment needs a workshop rig, so it is not a service we offer.
The car goes on a level ramp with a target or sensor clamped to each wheel. A camera or laser system reads the angles, and the technician compares them to the specification for your exact model. Three angles matter:
- Toe: whether the wheels point slightly inward or outward when viewed from above. The most common one to drift, and the one that wears tyre edges fastest.
- Camber: the tilt of the wheel in or out at the top, viewed from the front. Wears the inside or outside edge.
- Caster: the fore-and-aft tilt of the steering axis. Affects straight-line stability and how the steering self-centres.
On many cars only front toe is adjustable without extra parts, which is what a basic tracking check covers. A four-wheel alignment also measures the rear axle, which matters because a rear that is out of line will make the car crab and can be the real reason the steering wheel sits off-centre.
If a component is worn, alignment cannot be set accurately until it is replaced. A good technician will tell you that before adjusting anything. If you are unsure whether you need the check at all, look for the signs listed above.
