What are the causes of frequent punctures?

A flat tyre is one of the worst things to happen to a motorist, for the sheer inconvenience it causes. These days tyre technology has improved to quite an extent and so have roads, which theoretically should bring down the incidence of punctures. Here we look at what causes frequent punctures in tyres, and what can be done to prevent them.  

Tube type tyres

Tube type tyre are going out of style now as more carmakers adopt tubeless tyres for their cars. However, tube-type tyres are more prone to punctures than tubeless tyres for a variety of reasons. Tube-type tyres generally have a slightly thinner construction compared to tubeless tyres. Also read: 10 weekly maintenance checks for your car

Causes of punctures

The primary cause of punctures if of course penetration by any foreign object – nails, spikes, stones, thorns etc. When such objects pierce a tube-type tyre – the loss of air is almost instant, unlike in a tubeless tyre, where the object, if it stays embedded in the tyre, acts as a plug to the leak and air leaks out slowly.

Rust build up. In tube-type tyres, since there is a thinner inner tube inserted into the tyre, there is also more heat build up due to a small amount of friction between the tube, the inside of the rim and the tyre casing. Tubes tend to have multiple joints in them in the rubber which can give way, especially if there’s moisture and rust build up in the rim. This is one of the main causes of frequent punctures in cars with steel-wheels that have rust in them.

Incorrect inflation. Another cause of frequent punctures in tube-type tyres is over-inflation or under inflation of the tyre. When you overinflate a tube-type tyre, there is considerable stretching at the joints and if the tyre is worn out, any small object can easily puncture it. If you under inflate a tyre, there is greater heat build up inside due to more friction, which again makes it prone to punctures.

Faulty valves on the tube are a third common cause of frequent punctures and the only solution here is to replace the tyre tube.

Tubes that have been frequently patched up for puncture repairs too need to be replaced, as the puncture repair is usually the weakest point in the tube and it can open up again. Also read: What kind of tyres to choose for your car

 

Tubeless tyres

In tubeless tyres too the primary cause of punctures is the penetration of a foreign object into the tyre, leading to air loss. But unlike a tube-type tyre, the loss of air in a tubeless tyre is usually gradual. Tubeless tyres tend to have a thicker construction, especially for the sidewalls as they need to withstand stresses and retain air.

Rim bending is one of the biggest bugbears for cars using tubeless tyres especially with steel wheels. Tubeless tyres depend on an airtight fit with the edge of the wheel rim to contain the air, while the valve is a separate piece that also forms an airtight fit against the wheel rim’s valve hole opening.

Weak sidewalls. As tyres age, the sidewalls tend to get weaker. In such cases, you will notice significant sagging in the sidewall and sometimes bulges and cracks appear. Such tyres are prone to punctures and blow outs as heat builds up in them. Get them replaced as soon as possible.

Broken cords. Rarely there could be a fault with the tyre build itself – in steel belted radials, where one or more of the cords or belts inside the tyre carcass snaps and cuts through the tyre causing a puncture. This can happen in cars that have been driven over bad roads and sharp stones, or in cars that have been running badly under-inflated tyres. Also read: All you wanted to know about tyre upsizing

Puncture prevention tips

• Always maintain the correct tyre pressure and check the air pressure at least once a week if possible, when the tyre is cold
• Never over-inflate or under inflate your tyres
• Check for rim bending and rust build up and attend to this as soon as possible. Use alloy wheels if you can afford them.
• Carry a tubeless tyre repair kit and/or a portable air compressor in the car
• You could use products like Slime or other sealants in the tyre that will help seal minor leaks
• Ensure the spare tyre, jack and jack handle are easily accessible in the car

Share any other thoughts and experiences with punctures you have had with the CarToq community. Also read: 10 tools to carry in your car at all times.