Medium and soft tyres for Bahrain GP

In Bahrain, temperature drop of 15 degrees throughout the evening race. First in-season test of the year straight after Bahrain Grand Prix: Caterham, Mercedes and Williams will each devoteone day to do tyre testing.

Pirelli, along with all the Formula teams, tested at the Sakhir circuit twice in the build-up to the season – so this should be a circuit that everybody knows well. However, to celebrate its 10^th anniversary, the race has been given a 6pm start time for the first time in its history, meaning that it will start at sunset and end in full darkness: a bit like the Abu Dhabi Grand Prix.

This will have an important effect on the behaviour of the P Zero White medium and P Zero Yellow soft tyres that have been nominated for the race. Ambient and track temperatures will fall considerably during the race – with a drop in track temperature of 15 degrees entirely possible – which will alter the performance and degradation characteristics of the tyres. As night racing in Bahrain is an unknown quantity, the preparation work in free practice will be essential.

Paul Hembery, Pirelli motorsport director: “Bahrain is a circuit where we’ve done two recent tests, so we go there with a lot of knowledge of the track, which we certainly benefit from. We know that there’s a big traction demand and that’s why we’re bringing the medium and soft tyres. Temperatures at the start of the race should still be reasonably high. We’ve noted a very big drop in temperature though as soon as the sun goes down: a variation that can be as big as 15 degrees. Managing that very wide range of temperatures to get the best out of the tyres is going to be one of the biggest challenges for the teams throughout the weekend. This should make it quite tactical in terms of strategy, so it should be a very interesting race from that point of view.”

Jean Alesi, Pirelli consultant driver: ”I’ve driven in Bahrain but not in Formula One: instead it was in the Speedcar series, which was a little bit like NASCAR. So I got to experience the track and see that you need a smooth and clean rhythm to get the most out of the tyres, especially in the traction areas, so that you don’t put too much stress through them. The circuit is quite abrasive but it has a nice flow to it, although competing at night will be a new challenge. The most important thing is to try and control the degradation, but again, that might be very different after dark. It’s going to be interesting to watch and managing the tyres is definitely going to be important.”

The circuit from a tyre point of view:

Bahrain is quite demanding on the tyres, particularly during traction areas, with the surface tread temperature peaking at 130 degrees centigrade.

Aerodynamics is another important factor in Bahrain. With four 300kph straights, teams tend to use medium downforce, but this can compromise corner entry and braking stability, causing lock-ups that damage the tyres.

Sand on the track from the surrounding desert can also disrupt traction and cause wheelspin, leading to increased tyre degradation. Two years ago, a sandstorm actually halted one of Pirelli’s test sessions in Bahrain.

Braking is another key characteristic of the Bahrain International Circuit: in the first corner the cars decelerate from 315kph to 65kph in just 130 metres and three seconds. This places a force on the tyres equivalent to around 4.5g.

Following the Bahrain Grand Prix, the first two-day in-season test will take place (from April 8-9). Each team has to devote one day of testing to tyres this year, with Caterham carrying out test duties on the first day in Bahrain, and Mercedes and Williams testing tyres during day two.

Last year, Sebastian Vettel won the race from second on the grid using a three-stop strategy: starting on the medium tyre and then completing three stints on the hard. A wide variety of strategies were adopted, with some drivers also stopping twice.

The tyre choices so far: