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All snow tyres are designed for use at temperatures below + 7 degrees. Their rubber has a number of specific characteristics: at low temperatures it does not lose its elasticity, between the summer "village". Instead of the tyre tread, there are a number of special pits on the tread of these tyres. That is why they are sometimes referred to as lamealized or friction. The rubber properties and the tread pattern provide easy handling and efficient vehicle braking.
Types
Non-hashed tyres can be soft (Scandinavian) and rigid (European type). One of the main performance characteristics of the tyre is the speed index. It is represented by Latin letters on the side of the casing. The lower the speed index, the softer the rubber, and the longer the stopping distance.
Scandinavian tyres have a soft rubber and a lot of lamchales that provide excellent grip on ice and snow. Sometimes the tyres of Scandinavian tyres add silicon crumb to improve adhesion to the ice surface. These tyres have lower speed indexes (Q=160km/h, R=170km/h or T=190km/h). This type of covers is intended for regions with severe snowy winters.
Tyres of the European type have more rigid rubber and less (about 2 to 3 times) the number of lamops. The tread pattern of these tyres consists of large steps or ribs, which significantly improves the performance on asphalted road. It's a high speed tyre. Their indexes are N=210 km/h and V=240km/h. European tires are used in regions with warm winters. The advantage of this type of covers is that they can be visited on asphalt not only in winter, but also in autumn and spring period.
History of appearance
The first winter tyres were developed in Finland in 1934. The regional features of the region forced the Finns to think about making special tires "for the winter". At that time, the company Suomen Gummitetahtas (this company became the most famous Nokian producer) to produce the first tyres for snow-covered roads. That's how the shithelated rubber appeared. The tyres were unwieldy and inconvenient, and they were only remote.
In the 1960s, the first winter tyre model with a summer tread pattern and metal elements installed on it appeared. The rubber band was the same as for the manufacture of summer tyres, so it was not surprising that the rubber was cracking in the cold. Then, after a series of experiments, the industrial giant Metzeler proposed to add silicon to rubber. It was this element that allowed the rubber not to lose its elasticity and made it less susceptible to low temperatures. The tyres were soon found to be unsuitable for asphalt. In some countries (Japan, the United States, etc.), the use of such tyres was prohibited. Manufacturers considered the creation of winter tyres in which the main chaining element would not be thoras, but the structure of the tread. In 1982, the Japanese company Bridgestone was one of the first to produce snow tires. A few years later, this company's invention became a microporous rubber.
Faced with the need to improve the tread, the manufacturers offered very not standard solutions. For example, use on the suco tyres. However, the technology has gradually been consolidated into a large number of settlements on the block of winter protectors.
Today, many producers to increase elasticity are added to rubber in natural oils in an effort to make the production of tyres in an environmentally friendly way. This is where the next generation of innovation is linked.
The largest companies producing friction tyres: Continental (Germany), Nokian (Finland), Gislaved (Sweden), Michelin (France), Vredestein (Netherlands).
How it works
To improve the driveability on the ice, the working layer of friction tyres is made of a microporous rubber tyre. Sometimes these rubber patches of tyre contact with the road come to the ice like miniature crouching. This provides a short stopping distance and stable control of the vehicle on an icy surface. For even greater efficiency, the pads (blocks) of the tread are divided into a flat, not beyond the cap. Under the weight of a car the laidhs are opened and the tyre is attached to the ice. Outside the patch of tyre contact with the road, the load is lifted, and the lamapes converse again. This type of tyre has the name "Velcro" because of this effect.
In recent times glass fibres have been added to the tyre rubber tyres. These fibers are scratching the surface of the ice, which improves the grip of the tyre with the road.
Friction tyre proteges are directional, undirectional, symmetrical and asymmetrical.
The first and most common type of tread pattern is non-directional. It is called "undirected" because the tread properties are preserved regardless of the direction of rotation of the wheel. In other words, the clutch of the roadway will be the same for both forward and backward movement. This is a universal drawing, and most of these are manufactured in the automaker's factory.
The directional pattern is symmetric and asymmetric. If you conditionally draw a line around the top of the cover, the graphic to the right of the line is exactly the same as the one on the left. It's a tread with a symmetrical tread. A vector with an asymmetrical figure, as if it were composed of two different parts. This is done in order to improve the versatility of the tyres: one part (external, marked "outside") is designed for wet coating and is combating water. Second, internal ("inside") -for dry coatings.
The second type of tread pattern is directional. The tyres with this tread are particularly good for wet road surface, as the water comes out of the special "grooves". There is a special feature: it is important to properly install the cover, otherwise it will work incorrectly. You can determine the correct placement of the cover by an arrow that indicates the direction of rotation. Typically, manufacturers accompany the arrow with the inscription "rotation". If the direction of the "channels" is correct, then the water comes out from the contact stain, if there is no moisture, it will be collected from the edges of the wheel to the contact's stain. The second case could trigger a phenomenon such as water planning. That is, the water appears between the road and the staining of the contact and the car literally "pops up" and becomes unmanageable, which could lead to an accident.
The covers of this type may also have a symmetrical or symmetrical tread pattern.
Plus and Minus
After you have installed the unhashed tires, you don't have to worry about changing road conditions in the cross-season. Non-hashed tyres do little damage to the road surface. On the asphalted road these tyres have improved clutch. In addition, they are much quieter than rubber.
An unmistakable advantage is that, as the tread of the tread of the friction tyre tread on its surface, new pores are opened. This allows the retreading efficiency to be preserved in long-term operation.
However, the tyres that are unbearable play rubber with spike in ice and in the snow.
Operational issues
In the first 200 to 500 km, there is a hulk in the direction of the movement. In subsequent installations of this set of tyres, the original direction of rotation shall be observed.
