Studded Tyres

Studded tyres are necessary for the most difficult 'winter' driving conditions: ice close to melting point, hard snow, and 'verglas'.

They are called studded because of a system of studs inserted in appropriate grooves in the tread. Some countries have laws regulating the use of studded tyres especially in regards the period , the vehicle speed and the arrangement of the studs: number, position, and projection.

Here are the main rules that ETRTO (European Tyre and Rim Technical Organisation) recommends regarding the use of studded tyres:

• New studded tyres must be driven at a moderate speed for approximately 300 km (188 miles);
• If a car is to be equipped with studded tyres , they must be fitted on all the wheels of the car. If studded tyres are fitted on only one axle the road traction of the vehicle is actually less: fitting them on the front axle of front wheel drive vehicles reduces the braking and deceleration capacity on icy roads , fitting on the rear axle of rear wheel drive vehicles reduces the capacity of traction on bends;
• With studded tyres, sudden braking following rapid acceleration must be avoided
• When the studded tyres are fitted again after a period of non-use , make sure that they rotate in the same direction as the previous fitting. After each winter use, it is, therefore, important to mark the direction of rotation on each tyre as well as the position where it was fitted
• In the absence of more restrictive legal provisions the speed of 100 km/h (62.5 mph) should never be exceeded on roads without snow and ice because of the poor traction. Speed, acceleration, and sudden braking significantly influence the traction of the studs on tarmac.