GOOD MOTORING
Avert tyre trouble
H. Kishie Singh

The left unidirectional tyre on the front vehicle, which is wrongly positioned, will run backwards. This will adversely affect braking.

SOME time ago we discussed the latest on tyre technology. The latest tyres on the road are unidirectional i.e. they are designed to run and function in one direction only. If you took one wheel off the left-hand side and put it on the right side, it would not function. The very purpose it was designed for would be defeated.

So the first thing to bear in mind is that you cannot rotate your tyres in the conventional X pattern. In any case, radial tyres should not be crossed. What is recommended is the front to rear rotation. This means the tyres on the left stay on the left. The same holds for the other side too.

The reason for this is simple. Though all cars are manufactured to the same specifications, over the years they develop individual characteristics in handling and performance. This depends on the level of maintenance. Of course, the roads play an important role. Two identical cars bought the same day and run in different cities and on different road conditions will behave very differently at the end of 50,000 km of driving. The one in Chandigarh would be in excellent condition, for the suspension would have hardly been put to use. The second car, driven on pot-holed country roads, would have put the suspension through a torture-test. The amount of load a car carries also has a bearing on its condition. All these factors change the original geometry of the car. The left is different from the right. For this reason, the tyres should not be crossed ever.

In any case this will not be possible with unidirectional tyres. However, there is one problem you will face.

When you buy these tyres, two of them would function in one direction and three in the other direction. Your spare wheel, a unidirectional tyre, would run in only one direction. What if you had a puncture in one of the other tyres? When you fit the spare wheel, it will be running backwards! If you have a front-engine, front-wheel drive car, a limited slip differential would change the handling characteristic of the car entirely.

The tyre would provide no traction. In addition, it would make a lot of noise. Air would get trapped in the tread and the sipes. On a wet road, this would be dangerous, for cornering and braking would get affected.

The solution to all this is quite simple. Your spare wheel should be multidirectional. This way it can be fitted on either side without adversely affecting the handling of the car.

Most of these tyres are tubeless, which means that punctures are virtually a thing of the past. If you do not like to change a punctured wheel, there are some products in the market that can make life easier. Products like Fix-a-flat or Push-and-go are available. It’s an aerosol can and contains compressed air. A tube from the aerosol can is attached to the nozzle in the rim. Just a push of the button inflates the tyre. It would be a big help if the puncture-causing object could be removed before you re-inflate the tyre.

There is also a puncture repair kit for tubeless tyres. It’s really very simple to use but you need to reinflate the tyre after carrying out the repairs. For this, you will need a tyre repair shop with a compressor to reinflate the tyre.

Happy motoring.

This feature was published on February 7, 2004