The tires chapter F1,Formule 1, construct, konstrukce

The tires chapter

Miroslav Sanytrák / foto Jiří Křenek | 25.1.05 | Přední kolo

F1 construct

The tire allows safe ride thanks to precise leading of a wheel when going straight and in corners, ensuring the grip and resistance to skidding.

To achieve this, the sidewalls of the tire need to be elastic to a certain level but also firm. Such a feature is especially desired at the performance racing cars. It depends mostly on the construction of the tire, namely the tire cord installation and the compound.Development is heading to radial tires, providing lower rolling resistance with higher lateral stability. Tires' sizes are limited by technical regulations, which are a part of International sports code.As was mentioned earlier, the friction intensity between the tire and the road does not depend on the size of tire contact surface but exclusively on the friction coefficient f and normal component of the total load force N, described as T=fxN.

Pic. 1

You can see two tires of different widths in the figure 1. Let us assume the equal total load, the equal sidewalls elasticity, and therefore the equal specific pressures and equal sizes of the contact surfaces. However, the shapes of the contact surfaces are quite different. From the side view it is obvious that the compression of the wide tire Δh2 is not as significant as in the case of the narrow one. The ramp angel ß2 is on a hard road smaller than ß1, resulting in lower rolling resistance friction coefficient. Lower rolling resistance enables more efficient engine power usage.Vaclav Kral

Pic. 2

In the figure 2, there is a relation between the rolling resistance and the speed of the vehicle. The wide tire advantage is especially apparent at high speeds.The higher sidewall firmness of the wide-profile tires also helps with directional stability when rolling under lateral load, taking the inertia force load while cornering. The racing tires hand in hand with appropriate compound have become a key component of a formula car construction. In my opinion, even the ordered dry tires' grooves for formula cars mean a way ahead.