Can a Bent Alloy Wheel Be Straightened Safely?

How potholes bend wheels

When a wheel drops into a pothole and strikes the far edge, the force goes into the rim. A low-profile tyre offers little cushion, so the metal takes the hit and can flex or deform. The result is often a slight bend in the inner or outer lip that is invisible from outside the car.

Tyneside roads are not unique in having potholes, but winter frost and heavy traffic certainly produce them. If you hit one hard, it is worth checking afterwards instead of assuming no harm was done.

Wide wheels with thin sidewalls are the most exposed. The smaller the rubber between the rim and the road, the more of the impact the metal has to absorb, which is why larger alloys on fashionable low-profile tyres bend more readily than smaller ones.

Symptoms of a bent wheel

The classic sign is vibration that grows with speed, felt in the steering wheel or the seat. A bent rim can also cause a slow loss of tyre pressure if the bead no longer seals, and uneven tyre wear over time.

These symptoms can also come from an unbalanced wheel, a damaged tyre or worn suspension parts, so a proper diagnosis is needed rather than guessing.

If a vibration appears straight after a hard hit, do not wait to see whether it settles. Slow down, avoid fast roads and have the wheel and tyre looked at promptly.

• Vibration through the steering wheel or seat at certain speeds
• A tyre that loses air for no obvious reason
• A visible wobble when the wheel spins
• Odd tyre wear or a bulge in the sidewall
• The car pulling to one side after an impact

How wheel straightening works

The tyre is taken off and the wheel is mounted on equipment that measures its run-out, which is how far it wobbles from true. The repairer then applies controlled force, often with some heat, to bring the rim back into shape, measuring as they go until it is within tolerance.

Done skilfully on a suitable wheel, this can restore a smooth running rim. It is a specialist job, and doing it badly or applying too much heat can weaken the metal.

The finish usually needs refurbishing after straightening, since the process can crack the paint around the bend. It makes sense to treat the straightening and any repainting as one job so the wheel is completed in a single visit.

When it is not safe to straighten

Some wheels should not be straightened. A crack, however small, is the clearest reason. Heavily distorted wheels, wheels with damaged spokes or those that have been bent more than once may be unsuitable, as the metal fatigues each time it is worked.

Different alloys and wheel designs also behave differently. A repairer who inspects the wheel will tell you honestly if it can be straightened, and whether replacement is the safer course. We do not promise that any wheel can be saved before we have examined it.

Inspection and balancing afterwards

Once straightened, the wheel should be checked closely for cracks, including around the spokes and the inner barrel. A measurement of run-out confirms how true it now is. Then the tyre is refitted and the assembly balanced.

Test the car on the road afterwards. If the vibration comes back, tell the repairer, because it could point to another problem such as a damaged tyre or worn suspension parts.

What to do if you suspect damage

After a heavy impact, check the tyres for bulges, cuts or deformation, and watch your pressures. If the steering feels different or the car vibrates, avoid high speeds until it has been checked, and stop driving if anything feels unsafe.

At Banks of the Tyne in Hebburn we handle wheel straightening and alloy wheel repairs. Bring the car in and we will look at it, and give you an honest view on whether straightening is realistic.

Frequently asked questions