Thu March 1 03:14 pm 2007 in category Product news
Nokian Tyres plc
Press release 1 March 2007

New Ice Driving World Record: 321 km/h


- Nokian Hakkapeliitta studded winter tyres ensured grip in speedy driving



A new world record speed for driving on ice was achieved when four-times world rally champion Juha Kankkunen reached a speed of 321 km/h on a track ploughed on the ice of the Gulf of Bothnia next to the city of Oulu. Nokian Hakkapeliitta studded winter tyres ensured a firm grip.

The Guinness Book of World Records defined strict rules for this world record attempt: the speed was measured over a distance of one kilometre in both directions within one hour; the measuring point was in the middle of a straight part of the track; the ice had to be natural - it could not be roughed up or treated with any chemicals; and the tyres had to be approved for road traffic in the country in which the record attempt took place.

The significance of tyres is stressed under extreme speeds as the tyres are the vehicle's only point of contact with the substrate. The Bentley Continental GT used for the record attempt was equipped with Nokian Hakkapeliitta Sport Utility 5 studded winter tyres. The tyres have been designed and developed for city SUVs.

When driving on slippery ice at a very high speed, the tyres need to have a good grip, great durability and driving qualities to match the performance. At these speeds, the tyres and studs have to endure exceptionally demanding conditions. The acceleration formula is demanding: when a vehicle moves at a speed of 320 km/h, a stud weighing one gram creates a pulling force equivalent to approximately 2.2 kg. The vehicle covers 90 metres in one second, and each stud hits the ice more than 40 times a second.

"In order to achieve a steady driving speed of 320 km/h, you need gravity of approximately 300 kg or 3,000 N. For the vehicle to accelerate, you need even more force. The tyres must be able to transfer this force into the ice, or the tyre will slip and the vehicle will not accelerate as hoped," explains Nokian Tyres Development Manager Kai Hauvala.

As the air resistance increases, more traction is needed in order to pick up speed. The tyres are under immense pressure at these high speeds, and their diameter can increase by 15-20 mm.

The Nokian Hakkapeliitta tyres with their sturdy frame did very well in this demanding wear test: the tyres' grip was as good as hoped for and none of the studs came off.

For further information, please contact: Nokian Tyres plc
- Marketing Manager Antti-Jussi Tähtinen, tel. +358 3 340 7940
- Development Manager Kai Hauvala, tel. +358 3 340 7673

Photos
Nokian Hakkapeliitta SUV 5 product presentation