10/02/2006
It's a common, and often unavoidable, mishap for any driver: mounting a kerb. Whether it's a moment of inattention, a tight manoeuvre, or simply an unexpected obstacle, the impact of a tyre hitting a kerb can range from a barely noticeable jolt to a significant jolt that leaves you wondering about the consequences. While the immediate concern might be for the tyre itself, the often-overlooked casualty of such an encounter can be your vehicle's wheel alignment. This article delves into the intricate relationship between kerb impacts and wheel alignment, explaining why it happens, the tell-tale signs to look out for, and what you can do to rectify the situation.
The Direct Link: Kerb Strikes and Alignment Damage
Your car's wheel alignment refers to the precise angles at which your wheels are set in relation to the road surface and to each other. These angles are meticulously calibrated to ensure optimal tyre contact, balanced weight distribution, and predictable steering. When a tyre strikes a kerb with sufficient force, it exerts a powerful lateral or perpendicular force on the wheel assembly. This force can easily exceed the suspension's ability to absorb it without causing a shift in the carefully set alignment angles. Even a seemingly minor kerb strike can be enough to knock your wheels out of their intended position.
The primary components affected by a kerb strike that influence alignment are:
- Tie Rods: These are crucial for steering. A strong impact can bend or even break a tie rod, directly altering the toe angle of the wheel.
- Control Arms: These connect the wheel hub to the vehicle's chassis. A forceful impact can bend or damage control arms, affecting camber and caster angles.
- Wheel Hubs and Bearings: While less common, severe impacts can damage the hub assembly, leading to a misaligned wheel.
- Struts and Shock Absorbers: These components manage suspension movement. A kerb strike can damage them, indirectly impacting alignment by altering how the wheel sits.
The Consequences of Misalignment
The ramifications of compromised wheel alignment extend far beyond a simple annoyance. They can significantly impact your driving experience, your vehicle's performance, and your wallet:
1. Uneven Tyre Wear: The Most Visible Sign
This is arguably the most common and tell-tale sign of misaligned wheels. When your wheels are not pointing in the correct direction, they are essentially being dragged or pushed sideways across the road surface. This constant scrubbing action leads to accelerated and uneven wear patterns on your tyres. You might observe:
- Feathering: Where the edges of the tread blocks are worn smooth on one side and sharp on the other.
- Scalloping or Cupping: Patches of uneven wear appearing around the tyre's circumference.
- Inner or Outer Edge Wear: One side of the tyre tread wearing down significantly faster than the other.
As K&P Tyres (Ewell) Ltd rightly points out, tyres are the only point of contact between your vehicle and the road, and maintaining adequate tread depth is vital for safety, particularly for stopping distances. Uneven wear drastically reduces the lifespan of your tyres, meaning you'll need to replace them more frequently.
2. Compromised Handling and Steering
Misaligned wheels can make your vehicle feel unpredictable and difficult to control. You might experience:
- Pulling to One Side: The vehicle consistently drifts towards the left or right, even when the steering wheel is held straight. This often requires you to constantly counter-steer to maintain a straight path.
- Vibrations: You might feel vibrations through the steering wheel, especially at higher speeds, indicating that the wheels are not rotating smoothly or are out of balance due to misalignment.
- Slight Steering Wheel Angle: Even when you're driving in a straight line, the steering wheel might be noticeably off-centre.
3. Reduced Fuel Efficiency
When your wheels are not aligned correctly, your tyres create more rolling resistance. This means your engine has to work harder to maintain speed, leading to increased fuel consumption. While seemingly minor, this can add up significantly over time.
4. Increased Strain on Suspension Components
The constant stress of misaligned wheels puts undue pressure on various suspension and steering components, potentially leading to premature wear and tear on parts like ball joints, bushings, and the steering rack itself.
Identifying a Kerb Strike Impact
After hitting a kerb, it's crucial to be vigilant for any of the following signs:
- Auditory Clues: Did you hear a loud bang or a scraping sound during the impact?
- Immediate Handling Changes: Did the car immediately start pulling to one side or feel 'off' to steer?
- Visual Inspection of Tyres: Look for any new scuff marks on the tyre sidewall, especially on the side that made contact with the kerb. Check for immediate signs of uneven wear.
- Steering Wheel Position: Does the steering wheel feel off-centre when you're driving straight?
- Vehicle Pulling: Does the car veer to one side when you release the steering wheel momentarily on a flat, straight road?
What to Do After a Kerb Strike
If you suspect your wheel alignment has been affected by a kerb strike, the best course of action is to have it checked by a professional. Here's a recommended approach:
- Immediate Safety Check: If the impact was severe, pull over safely to check for any obvious damage to the tyre or wheel. If there's any sign of a punctured tyre, a damaged sidewall, or a buckled wheel, do not continue driving. Call for roadside assistance.
- Book a Wheel Alignment Check: Even if there's no immediate visible damage, it's wise to book an appointment at a reputable garage, such as K&P Tyres (Ewell) Ltd. They have the specialised equipment to accurately measure and adjust your wheel alignment.
- Inform the Technician: When you book or arrive for your appointment, clearly explain that you suspect a kerb strike may have affected your alignment. This information will help the technician focus their inspection.
Understanding Wheel Alignment Angles
To appreciate how a kerb strike causes issues, it's helpful to understand the basic alignment angles:
| Alignment Angle | Description | Effect of Misalignment |
|---|---|---|
| Toe | The angle of the wheels when viewed from above. If the front edges of the wheels turn inwards, it's 'toe-in'; if they turn outwards, it's 'toe-out'. | Causes rapid tyre wear on the edges (inner or outer) and can make the car feel nervous or unstable. |
| Camber | The inward or outward tilt of the top of the wheel when viewed from the front. Negative camber means the top tilts inwards; positive camber means the top tilts outwards. | Causes wear on the inner or outer shoulder of the tyre. Can also affect steering feel and cornering stability. |
| Caster | The angle of the steering axis when viewed from the side. It affects steering stability and the self-centring action of the steering wheel. | Affects steering effort and the vehicle's tendency to drift. Incorrect caster can make steering heavy or cause the car to pull. |
Preventative Measures and Best Practices
While kerb strikes can happen to anyone, adopting good driving habits can minimise the risk:
- Be Mindful of Road Edges: Especially when parking or navigating tight turns, pay attention to where your wheels are in relation to the kerb.
- Slow Down: If you need to approach a kerb closely, do so at a slow speed.
- Avoid Mounting Kerbs Unnecessarily: Unless it's unavoidable, try to avoid driving on or over kerbs.
- Regular Tyre and Alignment Checks: As a general maintenance practice, having your wheel alignment checked periodically (e.g., annually or after hitting a significant pothole) can catch problems before they escalate.
Frequently Asked Questions
Q1: Can a very small kerb bump misalign my wheels?
A: While a very minor bump might not cause significant misalignment, even a seemingly small impact can sometimes be enough to alter the sensitive alignment angles, especially if your suspension components are already slightly worn. It's always better to be safe than sorry.
Q2: How often should I get my wheel alignment checked?
A: It's recommended to have your wheel alignment checked at least once a year, or whenever you notice signs of uneven tyre wear, your car pulls to one side, or you've experienced a significant impact like a kerb strike or hitting a deep pothole.
Q3: Does hitting a pothole have the same effect as hitting a kerb?
A: Yes, both potholes and kerb strikes exert sudden forces on your wheels and suspension. The nature of the impact might differ, but both can lead to damaged tyres, buckled wheels, and misaligned wheels.
Q4: Can I check my wheel alignment myself?
A: You can perform a basic visual check for obvious signs like uneven tyre wear or a crooked steering wheel. However, accurately measuring and adjusting alignment angles requires specialised equipment and expertise found at a professional garage.
Q5: If my wheels are misaligned, will it affect my new tyres?
A: Absolutely. If your wheels are misaligned, fitting new tyres will not solve the underlying problem. The new tyres will also begin to wear unevenly and prematurely, negating the benefit of the new rubber. It's essential to address alignment issues before or immediately after fitting new tyres.
In conclusion, the humble kerb, often underestimated, can be a significant contributor to compromised wheel alignment. By understanding the potential consequences, recognising the signs, and taking prompt action, you can ensure your vehicle remains safe, efficient, and enjoyable to drive. Regular checks and mindful driving are your best allies in maintaining optimal wheel alignment and prolonging the life of your tyres.
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