Pirelli's new Sottozero Tyre makes its Debut in World Rally Championship in Norway
New studded tyre in 15" diameter reduces costs for teams Specialist winter tyre rims no longer needed
Milan, February 10, 2009 - WRC Norway, the second round of the 2009 World Rally Championship, starts from Hamar, 60km north of the nation's capital in Oslo. While the mainstay of the action runs on the frozen roads around the rally's hometown, Oslo will also play its part for the first time ever on Thursday (12th February).
The event gets underway from the Bjerkebanen racecourse close to the centre of the city. The two-kilometer crowd-pleaser is just a warm-up for the three days' of flat-out driving to come. All that awe-inspiring action will take place on a surface which the spectators can barely stand on. Heavy snowfalls in the lead up to the event have been compacted into a near-perfect ice base for the stages. As much as this is a true test of man and machine, it's arguable that it is the Pirelli Sottozero tyres which face the biggest test; the Italian rubber is the link between machine and mother earth.
During the rally, the manufacturer's cars will be positioned into what's known locally as the Vikingskipet, or the Viking Ship in English. This facility was built for the 1994 Winter Olympics, when it was used as the speed-skating arena. Next week, however, it will shield the world's highest-tech rally cars from the biting Scandinavian cold.
In a move designed to reduce costs, Pirelli has redesigned its Sottozero 'ice' tyre into a 15" diameter. Up till now virtually all WRC ice tyres have been constructed in very narrow 16" diameters with the objective of providing a long and thin contact patch capable of biting deep into snow, whilst still providing good traction.
With this being the only one truly 'winter' rally in the World Championship it has always been a costly exercise for the teams to buy bought stocks of narrow 16" wheels, which could not be used in any other WRC event.
Pirelli has carefully studied the problem and come up with a solution that had excellent results in pre-event testing. Armed with 384 studs, each 7mm long, the new Sottozero uses a very open, 'aggressive' asymmetric tread pattern and a thermal compound that not only satisfies the requirement of providing grip in sub zero temperatures, but is also able to retain the studs during hard driving. The size is 205/65 x 15, although the design has been optimised to create as narrow a contact patch as possible, consistent with use on a standard 7 x 15" rim.
Mario Isola, Rally Manager for Pirelli commented 'Rallying on snow is always a great spectacle but it is also highly demanding on the tyres. We have put a lot of work into this new Sottozero and we are sure it will give a high level of confidence to the drivers in the snowy conditions of Norway'