Kerbed alloy wheel: how to tell if it is still safe to drive

A kerbed alloy with only scuffs, scratches or a shallow gouge on the rim lip is safe to drive on, and a refurb is optional. It is not safe if the strike has cracked the wheel, bent it enough to shake or lose air, or damaged the tyre.

The MOT inspection manual lists any fracture in a wheel as a dangerous defect. This guide is about the wheel. It sorts the damage into three bands, then covers the checks to do, what the MOT says and who fixes what. If the rubber took the hit, our guide to kerb damage to the tyre goes into cuts and scuffs on the sidewall in detail.

Cosmetic, check, or stop: the three bands

Go by the worst sign you find, not the most visible one. A badly scraped lip with nothing else wrong is still cosmetic, while a clean-looking wheel that has started to lose air is not.

What a kerb does to an alloy wheel

The rim lip is the widest part of the wheel, so it meets the kerb first, and on a slow parking scrape that is usually all it touches. A harder strike, taken at an angle while turning or mounting the kerb, sends the force through the lip into the barrel and spokes, which is where structural damage starts. Wolfrace, a UK alloy wheel maker, notes that a hard impact can leave micro-fractures you cannot see, and that a badly kerbed wheel tends to stay deformed rather than spring back.

• Kerb rash: scraped paint and lacquer around the lip. Cosmetic.
• Gouge: metal taken out of the lip. Usually cosmetic when it is shallow and on the outer face.
• Buckle or flat spot: the rim knocked out of round, often on the inner edge you cannot see from the pavement. It shows up as a vibration or a tyre that will not hold air.
• Crack: a fracture in the rim, barrel or a spoke. Structural. The wheel should not be driven on.

Large alloys on low-profile tyres tend to come off worst, because there is so little sidewall between the kerb and the metal. A knock that a tall sidewall would absorb goes more directly into the rim. National, a UK tyre retailer, lists a "higher risk of damage from potholes and speed bumps" among the drawbacks of low-profile tyres, and notes that many have rim protectors "to help shield alloy wheels".

How to check a kerbed alloy wheel

The damage you can see from the pavement is rarely the damage that matters. The Wheel Specialist, a wheel repair firm, says a crack usually appears at the inner barrel, close to the bead seat, which is the part nobody looks at. Five minutes with a torch tells you far more than a glance at the scrape.

1. Look at the lip in good light. Run a fingertip round the scraped area. As a rough guide, marks you can feel but cannot catch a fingernail in are surface damage. A lip that looks pushed in or flattened is not, and if you are in doubt, treat the wheel as one to check before you trust it.
2. Turn the steering to full lock and shine a torch on the inner barrel and the backs of the spokes. Look for a hairline line in the metal, a dent in the inner edge, or a shiny spot where the tyre has rubbed.
3. Check the tyre while you are down there. TyreSafe warns that hitting a kerb, even at low speed, can weaken or fracture the tyre's inner structure. A deep cut, exposed cords or any tyre bulge means the tyre is finished, whatever state the wheel is in.
4. Check the pressure that day, then again a few days later. A tyre that keeps losing air with no puncture in the tread points to the wheel: a bent lip or a crack near the bead seat can let air out slowly. If your car has a tyre pressure warning light, the light coming on in the days after the strike is the same signal. Our guide to slow punctures covers how to find where the air is going.
5. Notice how the car drives next time. A new shake through the steering wheel or the seat, a pull to one side, or a steering wheel that now sits off-centre all mean something has moved.

A worked example (illustrative, not a real job). Say you clip the kerb turning into a supermarket bay. The front lip has a bright scrape you can feel but cannot catch a fingernail in. At full lock the inner barrel is clean, with no line in the metal, and the tyre has no bulge or cut. The pressure reads the same the next morning and again three days later, and the car drives as it did. That wheel is in the cosmetic band. Had the tyre been a few psi down on the third day, or had a new shake started, it would be in the check band instead.

Can a kerbed alloy fail the MOT?

Scuffs alone should not. The road wheel section of the MOT inspection manual (section 5.2.2) lists structural faults, not appearance. Kerb rash is not on the list. The wheel faults it does list are:

• Dangerous: "any fracture or welding defect on a wheel".
• Major: "a wheel badly distorted".
• Dangerous: a wheel "distorted or worn to the extent the wheel or tyre is likely to become detached".

So a cracked alloy fails, and so does a badly buckled one. The tyre on a kerbed wheel is tested too, under section 5.2.3:

• Major: a cut that reaches the ply or cords. If the cords can be seen, it fails whatever its size. If they can only be felt, it fails when the cut is longer than 25mm or 10% of the section width, whichever is greater.
• Dangerous: a lump, bulge or tear, or cords exposed or damaged.
• Major: a tyre not seated properly on the rim, which a bent lip can cause.

The tyre rules apply on the road as well as at the MOT. Regulation 27 of the Construction and Use Regulations makes it illegal to use a tyre with a bulge or with the ply or cord exposed. It also covers a cut that reaches the ply or cord and is longer than 25mm or 10% of the section width, whichever is greater. GOV.UK lists a defective tyre as endorsement code CU30, 3 penalty points.

Can a cracked or buckled alloy be repaired?

Sometimes, and it is a wheel specialist's decision, not a refurb job. The Wheel Specialist says many cracked alloys can be repaired by a specialist. The exceptions they list are a crack through the hub mounting area, which cannot be safely repaired; multiple cracks, or one that has spread a long way, which they say mean the metal has fatigued beyond recovery; and a wheel that has cracked again where it was repaired before, which should be replaced. Bear in mind that they sell repairs. A mild buckle can often be straightened by a specialist, after which the tyre goes back on and the wheel is rebalanced.

What a cosmetic refurb cannot do is make a damaged wheel strong again. Filler and paint over a crack hide it without fixing it, which is worse than leaving it where you can see it. For scuffs, gouges and diamond-cut finishes, our guide to repairing or replacing a kerbed alloy covers the refurbishment side.

To be clear about our part: we do not refurbish, weld, straighten or supply wheels. We are tyre fitters, which is why this guide has nothing to sell you on the wheel itself.

A shake after hitting a kerb: balance, buckle or alignment

A new vibration after a kerb strike has three usual causes, and they are fixed in three different places.

1. Balance. Michelin advises that a wheel hit by a kerb may need rebalancing. Imbalance shows up as vibration at specific speeds, felt in the steering wheel, the floor or the dashboard. A moved or missing balance weight is the simplest cause to rule out first. We do wheel balancing where the car is parked, on the van.
2. Buckle. If the shake comes back after a proper rebalance, the rim is likely out of true. That is a job for a wheel specialist, who can measure it and say whether it can be straightened. A wheel that visibly wobbles as it turns is in the do not drive band.
3. Alignment. Michelin also notes that misalignment can occur after hitting a kerb. The signs are a car that pulls one way, a steering wheel that sits off-centre on a straight road, or one tyre wearing fast on its inner or outer edge. The Highway Code links uneven wear to wheels out of alignment and says to have it corrected as soon as possible. Alignment needs a garage with an alignment rig, and we do not do it from the van. Our guide to alignment versus balancing explains how to tell the two apart.

If the car should not be driven

Do not drive on a cracked wheel or a tyre with a bulge or cords showing, even slowly to a garage. The Highway Code says to change a tyre only if you can do it without putting yourself or others at risk, otherwise call for help. Our guide to the spare wheel or space saver covers the limits of the spare.

If it happens on a motorway, do not try to deal with it there. Get out on the side away from traffic, wait behind the barrier and ring 999 or National Highways on 0300 123 5000. We can fit once the car has been moved off the motorway.

Kerb-damaged tyre? We fit a new one where the car is

If the kerb has damaged the tyre, or you are not sure the car is safe to drive, you do not need to drive it to a garage. Our 24/7 emergency tyre call-out typically reaches you 30 to 60 minutes after your call and costs the same at night, at weekends and on bank holidays. If the car is safe where it is and only the tyre needs replacing, book tyres fitted at home or at work instead. Fitting takes 20 to 30 minutes, the wheel is balanced on the van, and new tyres carry a 2-year warranty.

When you ring, it helps to tell us:

• where the car is, and whether it is somewhere safe to work;
• the tyre size from the sidewall (for example 225/40 R18);
• whether the wheel looks cracked or bent, and whether the tyre has a bulge or cut;
• whether you have a usable spare;
• where the locking wheel nut key is, or that it is missing, as we also do locking wheel nut removal.

If the wheel itself is cracked, say so on the call: a new tyre needs a sound wheel to go on, and we will talk through the options before anyone sets off.

How to stop kerbing your wheels

• If your car can tilt the passenger mirror down in reverse, use it when parking so you can see the kerb line.
• Approach kerbs slowly and leave a gap, rather than parking by feel.
• Take tight turns wider. Cutting a corner is how the rear wheels catch the kerb.
• Keep the tyres at the pressure in your handbook, so the sidewall gives the rim what protection it can.

The same slow, square approach protects the wheels over speed bumps and potholes, the other common impacts.

Sources

Checked on 2 October 2026. The MOT, legal and safety points come from the primary sources below. The wheel repair points come from the trade sources named. The kerbside checks and the drive-to-the-check advice are our own practitioner view, built on those sources, and the worked example is illustrative.

• MOT inspection manual, section 5: axles, wheels, tyres and suspension (DVSA)
• The Road Vehicles (Construction and Use) Regulations 1986, regulation 27 (legislation.gov.uk)
• Endorsement codes and penalty points (GOV.UK)
• The Highway Code, Annex 6: vehicle maintenance, safety and security (GOV.UK)
• Car tyres and your safety (TyreSafe)
• Wheel alignment and wheel balancing (Michelin)
• Cracked alloy wheel repair: can it be fixed? (The Wheel Specialist, a wheel repair firm)
• Can badly kerbed alloys be repaired? (Wolfrace, an alloy wheel maker)
• Low profile tyres: the complete guide (National, a tyre retailer)

How we check our guides: every legal, MOT and safety point is checked against the source linked beside it, and the date above shows when. If you spot something wrong or out of date, ring or WhatsApp us on 07717 389637 and we will check it and correct the guide.

Photo: Eduardo Valdes on Pexels

Frequently asked questions