What is a Velcro or friction splint?

Friction tire or "Velcro" is a class of winter tire that can cling to the ice surface without metal inserts. If in studded rubber the interaction of the slippery coating and the tread consists of the friction of the rubber and the adhesion of the studs, then in the friction one only the friction force is used.

The grip of the wheel with the road largely depends on the checkers of the tread pattern. The greater their number and the total length of the edges in the contact patch, the better the wheel will hold the winter road. During acceleration, the rear edge of the tread block is activated, while braking - the front.

Features and principles of friction rubber

The functional features of Velcro provide the special properties of rubber and the texture of the surface of the tire:

• a large number of lamellas;
• softness of materials;
• porous structure;
• abrasive microparticles.

All friction tires are connected by an increased number of sipes. The lamella is a thin strip of rubber into which the tread is divided. This separation increases the pressure on the coating, thereby achieving improved adhesion. There are the following types of lamellas:

• transverse;
• diagonal;
• zigzag.

The Velcro protector is equipped with lugs, like any other self-cleaning protector. The difference lies in the increased density of the arrangement, which positively affects the mileage, allowing the use of a larger number of lamellas. It is with the edges of the sipes that the tires cling to the surface, and in combination with the large tread depth, a stable and large contact patch is formed.

Under the weight of the car, the lamellas in the tread blocks separate, which literally sticks to the surface of the snow-covered roadway. When leaving the contact zone with the road, the sipes converge, and the tire self-cleans, displacing ice chips and snow.

But lamellas are far from the only important condition. No matter how many of them are provided, the maximum adhesion efficiency can only be ensured by the porous structure of the rubber. It is she who will absorb water when hitting the roadway.

The Velcro rubber contains a cryosilane mixture with silica, so it does not coarsen at low temperatures, and a large number of micropores drain the water film. At the molecular level, each tire pore interacts with the road surface according to the suction cup principle, which provides not only an effective traction function, but also a short braking distance. At the same time, many manufacturers declare the addition of solid microparticles of inorganic and organic origin to the rubber mixture. Such abrasives perform the function of a kind of mini-spikes, which only enhances the friction properties.

What is the difference between normal and friction rubber?

Where there is no ice and dense snow, the best solution is to use friction rubber. It is these conditions with a predominance of loose snow, snow porridge and wet asphalt that are typical for the streets of Ukrainian cities in winter. Friction tires can also be used during the period when it is still quite warm during the day, and frosts are possible at night and it is no longer possible to use summer tires.

These tires have a softer rubber compound than studded tires and tan less in extreme cold. Their ability to provide reliable grip with the road surface is maintained at temperatures of minus 25°C and below.

Friction tires do not have spikes. Therefore, one of their advantages over studded rubber quite obviously - they are much less noisy. On snow, there is practically no difference, but on ice or asphalt, friction tires are noticeably quieter. 

Studded tires out of competition on clean ice and packed snow. Spikes are especially useful on slippery surfaces at temperatures near freezing when there is a layer of water on the surface of the ice to act as a lubricant. Friction tires in such conditions are ineffective. Studs will be appreciated by inexperienced drivers. But the spikes are too noisy, not suitable for driving at high speeds, have an extended braking distance on wet pavement and cause significant damage to the road surface. In most European countries, their use is limited or completely prohibited.

All season tires are by no means the “golden mean”, as it might seem at first glance, since they are inferior in their performance to both summer and winter tires. This is nothing more than a compromise in an attempt to combine opposites. European motorists use such tires mainly in the off-season.

In the conditions of Ukraine and its northern neighbors, all-weather tires are of little interest. The temperature range of normal operation is quite narrow - from a slight frost to + 10 ° C. At the same time, reliable grip with the road surface is possible only on a flat and dry track. It is simply dangerous to ride on snow and ice on such tires. It will not be possible to save money by buying one set for all seasons, but safety or, at least, driving comfort will be at risk.