Why Hitting the Kerb Causes Tyre Sidewall Damage

We’ve all done it. A momentary lapse in concentration, a slightly misjudged corner, or a tight parking space, and you hear that awful, grating scrape of your wheel against the kerb.

While many drivers brush this off as a minor annoyance or a cosmetic issue for their alloy wheels, the reality is far more dangerous. “Kerbing” your tyres can cause severe structural damage that may lead to a catastrophic blowout on your next journey.

In this post, we will explore why kerb damage is so dangerous, how to avoid it, what it might cost you if you get it wrong, and what to do if the worst happens and you need to change a wheel at the roadside.

The Anatomy of a Blowout: Why Kerbing is Dangerous

A car tyre is not just a balloon made of rubber; it is a complex, highly engineered structure. The tread (the part that touches the road) is reinforced with steel belts to handle harsh drives, punctures and road debris. However, the sidewall, the smooth vertical face of the tyre—is entirely different. It lacks this steel reinforcement because it needs to flex and absorb bumps to give you a comfortable ride.

When you strike or scrape a kerb, you nick the flexible sidewall and your wheel rim on the kerb. This impact can tear the outer rubber, exposing the internal fabric cords (the carcass ply). Worse still, it can snap those internal cords without leaving an obvious mark on the outside.

When the internal structure is compromised, the air pressure inside the tyre pushes against the weakened area, often creating a visible bulge or “egg” on the sidewall. Once a tyre has a bulge or a deep cut in the sidewall, a blowout can occur. If this happens at 70 mph on a motorway, the sudden, violent loss of pressure will cause a massive loss of control, putting you, your passengers, and other road users in extreme danger.

It is important to note that unlike a simple nail puncture in the tread, sidewall damage cannot legally or safely be repaired. If the sidewall is compromised, the tyre is dead and must be replaced immediately. In the UK, driving with a damaged sidewall is also an instant MOT failure and can result in penalty points and a fine.

Common Causes of Tyre Damage

Kerbing during parking is the most famous culprit, but tyre damage occurs in several other common scenarios:

Turning too early: When turning left at a junction, drivers sometimes cut the corner too sharply. The front wheels might clear the kerb, but the rear wheels drag across the concrete apex, causing severe scraping and impact damage to the inner or outer sidewall.

Traffic islands and width restrictors: Approaching a pedestrian refuge island or a width restrictor without slowing down or aligning the car properly can result in a harsh, glancing blow to the tyre. Because the car is usually moving faster than it would be during parking, the impact force is much higher.

Potholes: The UK’s roads are notoriously plagued by potholes. Driving into a deep pothole at speed forces the tyre downwards into the hole and then violently slams it against the sharp exit edge. This “pinch shock” frequently destroys the sidewall and bends the alloy wheel. Recent data shows that pothole damage costs UK drivers an estimated £1.7 billion annually, with tyres and wheels being the most commonly damaged components.

How to Pull Alongside a Kerb Correctly

Prevention is always cheaper than the cure. Mastering the art of pulling up to the left can save your tyres and your wallet. Here is the best method for a safe, kerb-free park:

• Check your mirrors and signal: Always ensure it is safe to pull over before you begin the manoeuvre.
• Shallow angle approach: Do not dive toward the kerb at a steep angle. Bring the car in at a very shallow angle—almost parallel to the pavement.
• Crawl to a stop: Slow the car to a slow walking pace before getting too close to the kerb, as the vehicle comes to an almost stop, ease of the brake and use the roll to line up with the kerb.
• Use a reference point: Find a reference point on your car. For many drivers, when the kerb appears to intersect the middle of the dashboard or the base of the windscreen wipers (when looking from the normal driving position), the car is usually about a foot away from the kerb.
• Straighten up early: Before the car stops, steer slightly to the right to bring the wheels parallel to the kerb, then straighten the steering wheel completely.

The Cost of Mistakes: UK Tyre Prices in 2025

If you do destroy a tyre, you will need to replace it. Tyre prices have risen due to manufacturing and supply chain pressures. You generally have three bands of tyres to choose from, Budget, medium quality, and premium. It’s is highly recommended to replace tyres in axle pairs (both fronts or both rears) to ensure balanced handling and braking.

Tyre prices vary hugely, as an example a tyre on a average small vehicle in the UK can cost between £45 to £100

Roadside Rescue: How to Change a Flat Tyre

If you suffer a blowout or a flat tyre on a journey, you must know how to change it safely. Never attempt to change a tyre on the hard shoulder of a motorway. If you are on a motorway, pull over as far left as possible, exit the vehicle via the passenger side, stand behind the crash barrier, and call for professional breakdown recovery.

If you are in a safe, quiet, and flat location, follow these steps:

Secure the vehicle: Apply the handbrake firmly and put the car in first gear (or ‘Park’ for an automatic). Turn on your hazard lights.

Loosen the wheel nuts: Before jacking the car up, use your wheel brace to loosen the wheel nuts by about half a turn. (If you lift the car first, the wheel will just spin when you try to turn the wrench).

Position the jack: Look in your vehicle handbook to find the correct “jacking points” under the car sill. Placing the jack in the wrong spot can crush the car’s bodywork.

Lift the car: Jack the car up until the flat tyre is a few inches off the ground.

Remove the wheel: Fully unscrew the loosened nuts, take them off, and carefully pull the flat tyre off the hub. Slide the flat tyre under the car sill as a safety precaution in case the jack fails.

Mount the spare: Lift the spare wheel onto the hub and align the holes. Thread the wheel nuts on by hand and tighten them as much as you can with the wrench.

Lower and tighten: Remove the flat tyre from under the car, lower the jack until the new tyre is resting on the ground, and remove the jack. Now, use the wheel brace to tighten the nuts fully. Tighten them in a “star” or diagonal pattern to ensure the wheel sits perfectly flat against the hub.

Check the pressure: Spare tyres (especially space-savers) often lose pressure over time. Drive slowly to the nearest petrol station to check the pressure and ensure the nuts are secure.

Conclusion

Your tyres are the only contact between you and the road. Treating them with respect by avoiding kerbs, dodging potholes, and taking corners carefully is not just about saving money—it is about saving your life. Next time you park, take that extra five seconds to straighten up slowly. Your sidewalls will thank you.