Spanish GP, Barcelona Test 99-05-21

1999 SPANISH GRAND PRIX - PREVIEW SPANISH PRE-GRAND PRIX TEST (May 19/21)

Almost all of the F1 teams taking part in the three-day (May 19/21) test to prepare for the Spanish GP on May 30 had prior experience of the Circuit de Catalunya. This was perhaps fortunate, for variable weather hit the north of Spain throughout the test, making it difficult to record data under inconsistent conditions.

Despite wildly varying temperatures and, on Thursday, heavy rain showers affecting the circuit, lap times fell dramatically. Eventually it was Mika Hakkinen's McLaren which recorded the best time of 1m 21.711s, edging out Michael Schumacher's Ferrari (1m 21.820s).

For the race, Bridgestone will offer the same choice of tyre -- Soft or Medium -- to the teams, all of which now have plenty of experience with both types. It is expected that most of them will select the Medium, which is best suited to hot conditions.

"The Circuit de Catalunya is regarded by the teams as a track where lap times are often inconsistent, due to wide fluctuations in temperature and wind direction," says Yoshihiko Ichikawa, Technical Manager of Bridgestone Motorsport. "The road surface here is also more abrasive than most, which has required us to pay special attention to selecting the two compounds that we will offer the teams for next week's race."

For Bridgestone, says Ichikawa, Barcelona presents an additional challenge. "This is the first Grand Prix circuit we have visited this year where the tyres are seriously stressed," he explains. "Not only are the straights quite long by modern standards, which can lead to overheating of the tyre, but they are punctuated by corners which are mainly fast or medium-speed.

"The tyres must resist the combination of high speed and lateral g-forces generated in these faster corners," observes Mr Ichikawa, "and extra grip will obviously mean more stress."

Bridgestone will bring 2640 tyres to Barcelona for the Spanish Grand Prix. They will be divided between the two specs of dry tyre and two choices of wet tyre.

NOTE: G-Force from a tyre point of view can be explained as the lateral grip of the tyre which balances the centrifugal force due to the mass of the car travelling around the corner. The forces acting on a vehicle during cornering may be understood from the example of the forces acting on a ball being whirled around on the end of a piece of string. The centrifugal force generated goes in a straight line from the hand and through to the ball's centre of gravity. The opposing force, which prevents the ball leaving the circle it is describing, is the string. In this example the ball represents the car, whilst the string represents the vehicle's tyre in its role of containing opposing forces. If the grip of the four tyres is equal to the centrifugal forces generated by the vehicle going around a corner the car will remain on its chosen path. But should the centrifugal force become greater than the grip of the tyres, the result will be exactly like the string holding the ball breaking, the vehicle will leave the circle, out of control under the influence of the centrifugal force.