How to break-in new winter tyres
What for you need to break in winter tyres and how to do it in a right way
A tyre is an object that does not have moving parts, but requires running-in as a kind of complex mechanism. What can you do to keep your new winter tyres running for a long period of time?
Breaking-in is the process of mutual running-in of parts at the initial stage of operation of a complex multicomponent product. A tyre can hardly be called a complex and multi-component product, but it really needs a run-in, especially winter and studded tyres (a friction tyre is mentioned below).
How to break-in studded tyres
The main feature of a studded tyre is that each stud is not glued or cured into the tread, but simply inserted into a hole in the finished tyre and held there by frictional forces and rubber flexibility. A stud can jump out of a hole when external forces are strong. Such things do happen sometimes. Therefore, tyre manufacturers try to insert a stud into a hole as tightly as possible, paying particular attention to the diameter and shape of a hole, the properties of the rubber layer in which the hole is made, as well as the stud shape.
All present-day studs have one or two flanges, which are annular protrusions that prevent studs from jumping out. But these same flanges prevent studs from being inserted into holes, which have at least one flange extension.
Using a special pneumatic pistol, the stud is pushed into the hole, the rubber around the stud is unfolded and the stud itself is finally installed. When studding, some manufacturers use a lubricant, which partially dries out, partially comes out.
That's why a run-in is required. When a wheel rolls on the road, studs and tread around it experience the same load as in daily use, thus the studs and the walls of holes take their final and "mutually beneficial" position, both in depth and in diametrical direction.
Running in new studded tyres requires 500-1000 km, provided the following conditions are met:
● A car should have a full set of four tyres of the same model.
● Inner pressure should be monitored every two or three days. If during normal operation of tyres deviation of 0.1–0.2 bar is allowed, then during break-in the pressure must be strictly in accordance with the vehicle's manual. Inner pressure should be measured at the same tyre temperature (for example, always before or always after running).
● Tyres should be run in at above-zero air temperature, when tyre rubber is softer. Light frost is also allowed, for example, at night. Let us remind you that it is necessary to change summer tyres to winter ones when air temperature has reached +7 °C.
● Before using new tyres for the first time, you should record the vehicle odometer reading, as you will need to observe the break-in mode for 500-1000 km.
● Speed should be no more than 60 km/h. At higher speeds, the centrifugal force will tend to push the unsteady studs out. Besides, studs heat up more at high speed, especially on clean, dry asphalt roads. An overheated stud heats the walls of a hole and thus changes the rubber properties, which becomes harder and does not hold the stud so well.
● You should avoid abrupt manoeuvres: starting off with slipping, hard braking or small-radius turns at high speed. These are undesirable driving modes even for already run-in tyres, and newly installed studs can definitely loosen in their holes.
● You shouldn't turn the steering wheel when your vehicle is not moving, since this may result in loosening of the studs.
● You should not try to drive 500-1000, km in one run. You need to have breaks for studs to cool and rubber to unfold.
Some studded winter tyres have run-in indicators, which are fine cuts around each hole that wears off after the first 500-1000 km.
Why run in friction or studless tyres
Break-in of friction or studless tyres is needed to get rid of the top glossy layer of tread. Besides, on some new tyres, there are spew-pips and rubber hairs that prevent the tread from gripping well to uneven road surfaces.
100-300 km are enough to remove the top glossy layer of tread. A heavier car, such as a large crossover or SUV, needs 100-200 km, while a light hatchback will have to run 200-300 km in break-in mode. The running-in of studless tyres is considered over when the tread surface is rough and uniform, and there are no spew-pips, flash, rubber hairs, glossy areas or other signs of new tyres.
The above also applies to the Scandinavian type studless tyres. It is advisable to run on any type of winter tyres on asphalt and concrete roads. On unpaved roads, on ice and snow, it is impossible to achieve a constant and even load on the studs. You should also avoid driving on roads with lots of potholes. During the running-in period, you should not climb onto curbs when parking, slow down or take off on storm water drains, sewer manholes or other similar surfaces.
With careful break-in of winter tyres, at the same time, you subconsciously get used to safe winter driving without risky overtaking and last-minute braking, high speeds outside the city.
If you break in tyres following the above rules, their studs and tread will be in good condition and perform effectively for a long time, showing all the features laid down by the designer.