Snow tires are tires designed for use in colder weather, snow and ice. Snow chains can be an alternative in snowy conditions.
Snow tires have more sipes than summer tires, increasing traction on snow and ice, but reducing grip on dry and wet roads. Tires designed for winter conditions are optimized to drive at temperatures below 7°C (ca 46 Fahrenheit). The elasticity of the rubber in a winter tire shifts towards low temperatures and this guarantees better grip in winter conditions.
In much of Scandinavia, snow tires may have metal studs to improve grip on packed snow or ice, but such tires are prohibited in most other countries because of the damage they cause to the road surface. The metal studs are fabricated by encapsulating a hard pin in a softer material. The pin is often made of tungsten (wolfram) carbide, (hard metal). The softer base is the part that anchors the stud in the rubber of the tire. As the tire wears with use, the softer base wears so that its surface is at about the same level as the rubber, whereas the hard pin wears so that it continues to stick out of the tire. The pin should stick out at least 1 mm for the tire to function properly. Snow tires do not eliminate skidding on ice and snow, but they greatly reduce risks.
Famous quotes containing the words snow and/or tires:
“February is a suitable month for dying. Everything around is dead, the trees black and frozen so that the appearance of green shoots two months hence seems preposterous, the ground hard and cold, the snow dirty, the winter hateful, hanging on too long.”
—Anna Quindlen (b. 1952)
“Th’ increasing prospect tires our wand’ring eyes.
Hills peep o’er hills, and Alps on Alps arise!
A perfect Judge will read each work of Wit
With the same spirit that its author writ:
Survey the Whole, nor seek slight faults to find
Where nature moves, and rapture warms the mind;”
—Alexander Pope (1688–1744)