As they run on a road surface, our car tyres will gradually wear out. The soft-ish rubber of the tyres is constantly being abraded on the hard face of the stones that make up the road, tearing small parts of the tyre rubber off. Over time, your tyres will wear down sufficiently so that they have to be replaced with new ones. This is completely normal, and tyres are known as a consumable part that requires periodic replacement anyway.
What is uneven tyre wear?
Tyres tend to wear fairly evenly unless there is a problem elsewhere on the car, and uneven wear can be caused by a number of factors, leading to the tyre tread pattern wearing in a non-standard way. But what causes uneven wear, and what does it look like?
What causes uneven tyre wear?
Uneven tyre wear can usually be quite obvious and is characterised by parts of the road-contact surface that will look markedly different from the rest of the tyre.
Provided that the alignment of the wheels hasn’t been forced out of position by a road accident or kerb-mounting, tyres can wear in an uneven way due to a number of reasons, many of which are associated with the alignment of the chassis components associated with the wheels.
There are also some basic maintenance issues that can be the cause of uneven tyre wear too, so it is important to keep your car fully maintained as per the manufacturer’s instructions.
One of the biggest causes of uneven wear is tyres that are inflated to the wrong pressures, thereby putting different stresses on the tyre surface. If the tyre is over-inflated, the middle section of the tyre tends to wear more, and vice-versa.
- Incorrect wheel alignment:
Wheel alignment is sometimes called “tracking” and it relates to the position of the wheels and tyres to each other and the mass of the vehicle so that it is correctly distributed and keeps the car pointing in a straight line. Incorrect tracking forces the tyres into unnatural positions and exacerbates wear.
Wheels and tyres at the front of the car are set at slight angles to maximise their stability, particularly when corning, and to deal with the gentle curve of the road surface. This is known as toe-in or toe-out, and is sometimes called ‘camber’. If the toe angle is incorrect, it can lead to a type of excessive tyre wear known as ‘feathering’. This wear is allied to the alignment of the wheels and requires specialist aligning tools to rectify it.
If your suspension parts – shocks, springs, bushes, etc – are worn it can put excessive forces on your tyres, and affect how they wear. Problems with suspension can lead to so-called saw-tooth tyre wear.
These are areas of the tyre that have been worn down by excessive apply of the brakes and the locking of the wheels at speed, leading to an area of the tyres being worn flat, known as a flat spot. A flat spot will cause vibration through the steering wheel and will lead to extra wear on the edges of the spot every time the wheel revolves.
Preventing uneven tyre wear
Your tyres – like all other parts of your car – should be checked regularly to ensure that they are not wearing out excessively. Tyres wearing out is to be expected, but uneven tyre wear is not, so at the first signs of it, you should have your tyres checked by a specialist.
All modern tyres have tyre-wear indicators moulded into their contact surface. These are usually a series of lowered sections, below the normal tread which show you that the tyre is worn out when it abrades down to them. Because these extend across almost the entire width of the tyre, it is easy to use them to check for irregular wear on your tyres.
Your tyres are a hugely important part of your car, and you need to ensure that they are in the best condition. If there is evidence that they are wearing excessively or irregularly, you need to seek the help of a professional to rectify the issue.