4- WEIGHT TRANSFER

Now that we've Impressed upon you the Importance of pushing your tires to the edge of their performance envelope, you should know that this performance envelope is not always constant. The performance envelope will change continuously depending on road conditions, tire quality and driving technique. A simple example to illustrate this point is the difference In tire traction depending on the road conditions. There is a clear difference in traction on an asphalt road and on a dirt road, with the asphalt road providing a much larger friction circle. Even with the same asphalt road, the traction will change dramatically depending on whether it is dry or wet. As for tire quality, sports tires provide much greater traction than normal tires. The size of a tire also affects traction, with a larger contact surface area between tire and road providing greater traction. Driving techniques such as weight transfer also affect the tires' road gripping ability. A car's weight is supported by Its four tires. If a car weighs 1000kg and its weight is distributed evenly between front and rear and left and right sides, then each tire supports 250kg. This of course only applies to a car at rest. As a car begins to move, this weight distribution changes. For example, a car at rest viewed from the side will appear level. But once the car begins to accelerate, Its tall will sink down. If the brakes are applied, the nose will dip. This is due to the weight transfer occurring in the car. At rest, the front and rear tire sets each support 500kg. During acceleration, however, weight is transferred to the rear. If the load in the rear increases to 600kg. the load in front decreases to 400kg. This weight transfer can be felt when driving. If you step on the gas, your back gets pressed against the car seat. If you step on the brake, your body leans forward.

Depending on the weight transfer that occurs in a car, each tire's traction will change. As more weight is transferred to a tire, its traction also rises. To illustrate this example, think about a pencil eraser. The harder you rub it against a piece of paper, the greater the friction between the eraser and paper. If a car supporting 500kg on the front tires at rest decelerates so that the front load increases to 600kg, the traction of the front tires will rise accordingly. In terms of the tires' friction circle, think of the circle increasing in size. If the load in front increases 20% from 500kg to 600kg, then the surface area of the friction will also increase 20%. By using the weight transfer that occurs in a moving car, you can do things like stabilize the car or drive faster.

Always be aware of how much weight Is being carried by each of the car's four tires.