Tyre bulge: is it safe and what can cause it?

The tyre sidewall is the area most at risk of developing bulges. The sidewall is the area where the tyre meets the wheel rim and the tyre thread, which is the part of the tyre that makes contact with the road surface.

Nylon fibres form a crucial part of the sidewall structure, but these fibres are generally thin. When the rubber is damaged, air is pushed along these nylon fibres, creating a bubble, and bulge appearance.

There are a multitude of factors that can lead to a bulge. The most common are:

1. Over-inflation of tyres, which causes the tyre to expand too much and can bulge the sidewall.
2. Hitting potholes and speed bumps, especially when travelling at high speeds can create punctures and gashes.
3. Frequently hitting a kerb when parking.
4. Manufacturing defects can occasionally be responsible for a tyre bulge.
5. Car accidents which may inflict substantial damage to the tyre casing.

Front tyres are more commonly impacted by tyre bulges because they tend to hit kerbs more than the rear wheels.

The only answer to that question is yes. Tyre bulges represent a serious hazard on the road if the tyre is not replaced promptly. The tyre could burst, potentially resulting in the loss of control of your vehicle.

The impact of driving at high-speed places significant pressure on the weakened tyre, increasing the likelihood of a tyre blowout. Driving over a pothole, speed bumps and rocks when the tyre is damaged is very risky. Additionally, heavily overloaded vehicles expand the bulge as the heavy weight places too much pressure on the tyres. Another risk factor is sudden and heavy braking, which can easily cause the tyre to blow out.

As soon as you realise that there is a bulge in the tyre sidewall, you can take some steps to deal with the situation. If it happens while you’re driving, the first recommendation is to stop the vehicle and change to a spare tyre if possible. If you do not have a spare tyre, the best thing to do is to call a tow truck to help you.

It is not possible to safely fix a tyre bulge because the structure of the tyre is no longer stable. As this damage has such serious consequences, a fix is never recommended because it can never retain the initial structural integrity of a tyre before a bulge.

Left alone, a tyre bulge can progress into expensive damage to other parts of your vehicle. Damage to the suspension and other wheel parts are a real risk with a sidewall tyre bulge. In short, it is simply a matter of time before the tyre blows. Replacing the tyre at the earliest opportunity is the only way to continue to safely drive your vehicle.

There are some simple measures that can be taken to reduce the chances of a tyre bulge. A regular check of tyre pressure is very important, particularly during the summer, as higher temperatures can cause the expansion and contraction of the rubber, leading to more tyre wear and tear.

Buying quality tyres, coupled with good driving practices and maintenance can help reduce tyre bulge incidences.

If you have questions about tyre rotation or other aspects of your tyres, get in touch with your nearest tyre dealer and stay safe on the road.