Every cloud...

You will often here of people discussing tyre blow-outs, mainly because this is something that many will fear will happen to them. A tyre blow-out, to give it a definition, is the sudden and total deflation of a tyre caused through the collapse or failure of its structure. There is a tremendous amount of rubbish talked of when it comes to blow-outs and something that is severely misunderstood amongst the motoring population. Blowouts do not just happen, they are caused, and that cause 99.9% of the time is through negligence, in terms of simple maintenance and regular visual chacks, coupled with a lack of awareness.

As mentioned earlier, the air pressure within a tyre is necessary to maintain the integrity of the profile of that tyre and therefore its structure. If you steadily reduce the air pressure within a tyre you will reach a point, long before it becomes flat, where the tyre walls begin to bulge outward. If that car is driven with the soft tyre, the bulging tyre wall, now less rigid due to lost air pressure, will begin to distort and even ripple as the wheel rotates. This rippling effect causes friction within the rubber, and as you know friction causes heat. All the time a car is being driven along the road with a tyre in this condition that tyre is generating heat within itself and the level of heat will be rising for every metre of distance it is allowed to drive over. Eventually there will come a point when the tyre will have had as much heat as it can tolerate, and when that point comes it will suddenly let go with a bang. If you realise what is going on before you get the final failure point, and you try to put your hand on the tyre just after you have come to a stop, you will burn yourself. There is a terrific amount of heat generated here and tyres running on a vehicle whilst under inflated have even been known to ignite.

Let us not get carried away here, but instead ask ourselves why the tyre has gone soft in the first place, after all, that is the cause of the problem and the beginning of this chain of events? The answer is that you have either picked up a nail, or similar, that is stuck into the tyre body and you now have a slow puncture, or it might even be that the pressure has not been checked for so long that the tyre has gradually deflated little by little through age and neglect. It could be that you have been running around for weeks like this, but because you have been the only occupant of the car you have got away with it. Now, when you have got three other people on board and a boot full of luggage, things are very different.