Corner Safely And Rapidly

Press, Volume CIII, Issue 30365, 14 February 1964, Page 9

Corner Safely And Rapidly

J? VERY year there are manv accidents caused by Drivers losing control of their cars on corners and curves. Most of these are unnecessary ®nd would be prevented if Drivers had a proper idea of the behaviour of a vehicle when cornering. Always remember the saying attributed to a famous racing driver: “In slow, out fast. In fast, out feet first.” You will not go round a corner any quicker by coming into it too fast, come in slowly and accelerate smoothly and safely out of the turn. Thus corners can be negotiated safely and rapidly—but remember safety comes first.

When a car rounds a corner it is held on the road only by the tyres bearing on the road—that is the tyre adhesion. This adhesion is reduced in the wet, on some types of road surface, or if the tyres are worn. Thus all these factors call for considerably reduced speed.

The adhesion of the tyres can also be affected by the car itself, faulty shock absorbers, incorrect wheel alignment, overloading and so on. Incorrect tyre pressures may also reduce the amount of adhesion available. Accidents are caused when a car attempts to round a corner at such a speed that the tyres lose their grip on the road, that is when the limit of adhesion is exceeded. In some cars it wifi be the rear tyres which lose their grip first, sliding outwards and making the car turn more

| sharply. This is called over- ■ steer, and if allowed to pro- ' gress unchecked may result I in the car going sideways and \ possibly rolling over. If this does not happen the car may spin. Once the car ; is sideways on, the drag of | the tyres will cause it to decelerate very rapidly, but ;it is not a recommended j method of bringing a car to I a halt! | With some cars the front I wheels will lose their adhe|si on or “break away” first. I This is more dangerous and J harder to control than oversteer, and is known as under- | steer. The car attempts to go ! straight on although the | wheel is turned. The front j tyres merely scrub sideways, i Understeer is aggravated 1 and sometimes produced by i braking. If the front wheels i are locked they break away j much more easily. In such an event releasing the brakes I and accelerating hard may I save the situation. Or it may J not. The best rule is “don’t I get into an understeer slide.”

If you do, steering may be I improved if you twitch the i wheel. This sometimes allows I the road wheels to retain I enough grip to get the car around the curve. Racing A racing drivers’ trick to overcome understeer is to whip the gear lever to a lower gear and release the clutch with a jerk. This momentarily locks the rear wheels, breaking their adhesion with the road and promoting a change to oversteer. However, it is of technical ■ interest only to the ordinary I driver, as by the time he | realises he is in the grip of understeer there is no time left for such exercises, and attempting them unsuccessfully might only make matters worse. | All modern cars have a tendency to understeer, as this I makes them basically stable and run true in the straight ahead position. If a car oversteered it would progress in a series of swerves. With most cars the understeer characteristics, are prominent up to a certain speed, when a transition to oversteer takes place. Various factors can make the transition from understeer to oversteer occur earlier. A slippery surface or hard acceleration while turning, for instance. Many drivers will have had the experience on a grave] road of braking for a corner seen too late, turning at the same time, but finding the car continuing straight ahead. This is understeer. If the will immediately start toturn If the wheel has been hard over before the brakes were released this may be

very sudden and severe, possibly causing loss of control. In such a situation it is better to overshoot the turn and reverse back to it. Speed Considerable skill and experience is required before a driver can assess the speed at which he can safely and comfortably proceed around any certain corner. A car with a low centre of gravity, too, will corner better than

a top heavy car, or one that has been made so by, for instance, an overloaded roof rack. The limits of each car are different and the driver must be aware of them.

A good driver adjusts his speed before he reaches the curve, if it is too high he brakes, and if necessary changes to a lower gear. Once he has started to go around the bend, and can see the road ahead is clear, he accelerates and drives around. He judges the amount of acceleration necessary by the type or condition of the road surface. Except in an emergency you should never have your brakes on as you turn a comer or go round a curve. To do so is very bad driving, it reduces the cornering power of the car and can lead to dangerous instability and skids. Similarly, a conventional car should not be driven around a curve with the accelerator being released at the same time. Before reaching the curve you should position your car correctly so as to make as much use of the clear space on your side of the road as

possible, thus “straightening out” the curve to some extent. Thus, on a right-hand bend the car should be kept as close as possible to the lefthand side of the road before entering the curve. Then you should drive in as straight a line as possible across the comer without crossing the centre line. The "Line" When taking a left-hand bend start from as near the centre-line of the road as is safe, and take the straightest line possible across the curve. In this case such a line will take you close to the lefthand verge of the road at the top, or apex, of the bend. Taking the correct line around a bend in this manner also allows you to see the road further ahead. Taking the example of a left-hand bend again: by being nearer the white line at the start of the bend you will obviously be able to see further around it than if you were close in to the left of the road.

It is most important to remember you must always be

travelling at the right speed and in the right gear before you start to turn. It is dangerous to attempt to change gear or brake while in the process of turning. Accelerate Having entered the curve at the right speed and taken the right line around it, the car should leave the curve accelerating smoothly,, and on the right side of the road. If you go into the corner slowly, you can accelerate out of it rapidly with the maximum of safety and the minimum of discomfort to your passengers. If you come into the corner too fast you may be lucky and manage to get around it, probably on the wrong side of the road, well shaken up both literally and figuratively. You may be unlucky and be carried out.. Brake as necessary on the approach to a bend, select a lower gear if necessary, choose and follow the correct line, accelerating as the bend is rounded, and change gear when the road has straightened out once again. Always take careful note of any warning signs before bends, nearly all the bad bends in Canterbury are well posted by the Automobile Association. Advisory speed figures should be adhered to.