06/08/2013
(1) Tyres are critical components of the car and need to be in good shape for your own safety. Therefore, if a tyre goes bad, it’s always better to replace it rather than repair it. But how do you know when it’s time to replace your tyres?
(2)Tread Depth
Over a period of time the tread on a tyre will wear down to a minimum level. Never let the tyre go fully bald as you can lose control and skid easily and braking effectiveness will be reduced. By the time it goes bald, it’s usually too late and you’re lucky if you don’t have any mishaps. To check the tread depth of the tyre there are two ways. The minimum tread depth on a tyre should never be less than 2 mm.
To check this, every tyre has what is called a “tread-wear indicator”. This is a rubber strip that you will find if you look within the grooves of the tread. Its location is also marked by an arrow on the sidewall of the tyre. If the tread height and the height of the tread-wear indicator are same, it’s time to change the tyres. If the tread-wear indicator is below the height of the tyre tread, you still have life in your tyres.
Coin trick
The other simpler method to check tread wear is to insert a Rs. 1 coin in the tread of the tyre. If the tread does not reach the base of the Ashoka lion head, and you can see the words “Satyamave Jayate” on the coin, it’s time to replace your tyres.
(3) Uneven wear
If you have some suspension related problems or alignment problems, these can take the life out of your tyre quite quickly. Check each tyre for uneven tyre wear. If you find some parts of the tyre have worn more than the other parts (like the inside has worn out more than the outside), you can get your alignment corrected and suspension checked. Then get the wheels rotated and the tyre moved to the opposite side of the vehicle, which should hopefully help wear it out evenly. Emergency panic braking and hard braking can also lead to uneven tyre wear and flat patches. If the tyre has worn unevenly it will need to be replaced as you will get vibration and a poor ride quality from it.
But if the tread has worn down to the minimum tread depth, even if the wear is uneven, you will have to replace the tyre.
Bulging sidewalls
The sidewalls of the tyre are what support the weight of the vehicle and are built quite tough. They also need to be supple enough to flex a little to cushion road undulations as well as allow for better handling while cornering and improve ride quality. All radial tyres tend to bulge a little at the bottom of the wheel, which is fine. However, if you find bulges like blisters or bigger lumps on the sidewalls, that means it is weak and can blow out at anytime under stress. If you have bulges in the sidewalls you will need to replace the tyres.
Cuts or cracks in sidewall
Cuts and gashes in the sidewall are caused by sharp objects that the tyre brushes against. These could be stones or rocks by the roadside or even banging the wheel against the pavement unwittingly. If you have a gash or a cut in the sidewall, but no puncture, you will still need to replace the tyre as it will be weak and any heat during running will only increase the size of the cut and lead to a blow out. Also read: Buying alloy wheels for your car
Frequent punctures
Sometimes a tyre that has run a fair amount will still get frequent punctures. This could be because of a damaged belt or cord in the tyre. These belts and cords are built into the structure of the tyre and they are what give it rigidity. However, if you hit a speedbreaker or pothole hard, sometimes these cords or belts can snap and then poke through the tread causing a puncture or slow puncture. You cannot repair such punctures and the tyre will need to be replaced.
These days most cars come with tubeless tyres, which are better than tube-type tyres as they are less prone to blow outs and sudden punctures. However, you need to make sure you check your tyres once every fortnight and maintain the optimum tyre pressure. Under inflation or over inflation will lead to uneven tyre wear. Also read: 5 tips for buying new tyres
Share any more tips you have on tyre maintenance and experience with tyre wear with the CarToq community.
