Following the month-long summer break, Pirelli returns to action with the hard and medium tyres: a combination that has not been raced since the second Grand Prix of the season in Malaysia.
The conditions at the legendary Spa-Francorchamps circuit will be somewhat different however. The 7.004-kilometre lap is the longest of the entire year by some margin, and this is just one of the factors that can lead to extremely variable weather conditions, with a high risk of rain. Set within the Ardennes hills, Spa?s geography also ensures that it has its own microclimate, meaning that it can often be raining on one part of the circuit but be completely dry on another part.
The track is renowned for its high speeds and fast corners. It is also challenging on the tyres, which have to cope with extremely high lateral and longitudinal energy loadings, thanks to fearsome compressions such as Eau Rouge: a corner that feels like the ultimate rollercoaster ride. This is why the two hardest compounds from Pirelli?s range have been chosen, reflecting all the hard work that the tyres will have to do during the 44-lap race.
As Spa is such a long and variable race, there is ample scope for strategy to come into play, but tactics always have to be extremely flexible to cope with the potentially changeable weather conditions.
Technical Tyre Notes
The cars are at full throttle in Spa for nearly 75 percent of the lap, which makes it one of the quickest circuits of the year together with Monza - which takes place the following weekend. The high speeds increase tyre temperature, particularly if an aggressive camber set-up is adopted to maximise grip.
With all the compressions at Spa, getting the ride height and suspension travel correct is vital as otherwise the cars could bottom out at some parts of the circuit. The tyre forms a vital component of the car's suspension, with the deformation of the rubber under load making up nearly half a Formula 1 car's total suspension travel.
Despite the famously high straight-line speeds in Spa, the cars run a medium downforce set-up in order to optimise grip through the many fast corners. Traction is a particularly vital factor at places such as La Source hairpin, where the mechanical grip from the tyres is key to a clean exit.
In the famous Eau Rouge compression each front tyre is subjected to a maximum peak of vertical loads of more than 1000kg.
Pirelli in Belgium
Pirelli has a long history of success in Belgium, winning the Belgian Grand Prix on the old Spa circuit five times in total, from 1950 to 1954 inclusive. Two of the wins were with the legendary Juan Manuel Fangio and two were thanks to Alberto Ascari, the other victory being claimed by Nino Farina. Last year's winner - when Pirelli returned to F1 - was reigning champion Sebastian Vettel, for Red Bull.
As well as Formula 1 victories, the Spa-Francorchamps circuit has proved to be one of Pirelli?s most successful arenas in GT racing, with the Italian firm taking a clean sweep of wins with a wide variety of different cars, from the Maserati MC12 to the Chevrolet Corvette C6R.
Paul Hembery, Pirelli Motorsport Director
"The Spa circuit is a personal favourite of mine. I recently visited the 24-hour race there: the configuration of the track and the variety of the weather always seems to produce some great racing. From a tyre perspective, it's certainly one of the most demanding circuits that we face all year, because of the high speeds and extreme forces involved, which are often acting on the tyres in more than one dimension. The nomination of the hard and the medium tyres will allow drivers to push hard from start to finish, which is what Spa was designed for. The first half of the season began with the most close and competitive start to a year ever seen in Formula 1's history, so I am looking forward to seeing how the rest of 2012 pans out, and which teams have made which steps forward over the summer break. Currently the grid is so closely-matched - particularly in the midfield - that it's impossible to predict."
Jean-Eric Vergne, Toro Rosso
"After the long summer break, I?m keen to start racing again and what better place to do it than Spa. I?ve raced here a few times before, in the Renault 2 litre class, Formula 3 and World Series and I had what I consider to be the best weekend of my entire race career at this circuit, when I won all three Formula 3 races, including the one with the reversed grid order. So I have plenty of great memories and regard Spa as my absolute favourite race track and, until we have a French Grand Prix again, I think of it as my home race. It?s a brilliant circuit to drive and I?m looking forward to experiencing it for the first time in a Formula 1 car. With its long flowing corners, apart from the Bus Stop and La Source, it is not particularly tricky to work out what to do with the Pirelli tyres, but the conditions in Belgium do make the situation complicated. And, with the circuit being so long, you don?t get to do so many laps, which means you need to make the most out of your tyres, in qualifying for example. I wouldn?t be surprised if we end up trying the entire range of tyres that will be on offer in Belgium, from the medium and hard slicks, to the Intermediates and Extremes, as rain is never far away in Spa. But that?s part of the fun, part of what makes Spa Spa."
Jaime Alguersuari, Pirelli Test Driver
"I think Spa is a fantastic race because of its rich sporting history. It is also home to some of the most famous corners on the Formula 1 circuit, including Eau Rouge and Blanchimont. There are a lot of high-speed corners, but also some straights making it a very fast circuit. Spa will challenge both the drivers and the teams as it is a circuit that requires a medium downforce set-up and good mechanical grip. For me, next week will be very interesting as I set my fastest qualifying in Spa last year. My most recent test with Pirelli was also in Belgium and you will struggle to find any driver that does not enjoy this race. From a tyre point of view, Spa is relatively smooth, so it is not tough on the tyres but it does pose its own unique challenges. There are a lot of high-speed areas where considerable lateral force is put on the construction of the sidewall. It is similar to Japan?s Suzuka race circuit, and requires the same set-up and handling."