Does the grip of the tires have any relation to the steering of a vehicle in any way?How important is the grip of tyres to steering?
If tyres do not grip, you cannot steer. This proves how greatly grip is related to steering. Imagine driving on ice. Tyres will not grip and you cannot even start the car, nor can you make a turn or stop.
In F1 racing, tyres must have firm grip so that drivers can have proper steering. Moreover, characteristics of steering performance may change depending on the balance between the grip of front and rear tyres.
When making a turn, if front tyres have a stronger grip than rear tyres, front tyres will be taken in too much toward the inside of the corner, which is over-steering. On the other hand, if grip of rear tyres were stronger than front tyres, rear tyres will push out the front, causing under-steering. In F1 racing, because rear tyres are normally wider than front tyres, strengthening the grip which most likely results in an under-steering situation. Proper grip balance between front and rear must be achieved, based on this understanding.
Currently, grooved tyres are used in F1 racing, which have less area of contact with road surface and weaker grip than former slick tyres. These grooved tyres must have greatly influenced steering performances.
It was difficult at the beginning. Grooved tyres made steering unstable, not only due to their weaker grip, but also because blocks on tread were flexible. If hard rubber were used to avoid such flexibility, then the grip will be weakened. Yet again, using soft rubber to attain better grip would cause the blocks on tread to become too flexible, resulting in poor steering performance.
In order to solve these two contradicting problems, a type of rubber that is firm enough yet provides strong grip was developed. Lack of grip of front tyres due to their narrower width compared to rear tyres, was solved by upsizing the external diameter, in addition to improving the rubber quality.
We often see mechanics checking the air pressure of tyres throughout the race. Does this have anything to do with grip and steering?
Yes, definitely. That is an important point. Referring to “structure,” tires can display their performances only when they are pumped up with air. Yet, area of contact with road surface will be reduced if tyres are over inflated, which causes loss of grip. On the other hand, if not enough air is admitted, tyres cannot properly support the machine although grip power may increase. This may lead to trouble. Therefore, the inner air pressure of tyres must be set within proper levels. Top drivers of F1 and Formula Nippon series all have a keen awareness, in that they are able to sense the difference in grip or steering performance, even by a slight change in air pressure of 0.05kgf/cm2.