First of all, new tires, no matter what quality they are, you must correctly "obkatat. This will prolong their life, will ensure reliable coupling with the ground.
Bus to run in at low speed (60-70 mph). It suffices to 200-300 kilometers. This is true not only for the studded tires, but even for the standard tires with non-directional tread pattern.
No doubt the fact that the life of rubber depends on how you operate the bus. This manner of driving and the engine power, and the quality and character of roads, which are mainly operated by bus, and speed, and many other factors.
Naturally, the fast driving and driving speed, active inhibition lead to rapid wear of the tire. This is especially true for winter tires (no matter - studded or friction). They are known to be designed for the harsh winter conditions, softer summer, so at a time when summer tire "kept a stiff upper lip", Winter feels reinforced load.
To bus served for a long time (3-4 years), you should periodically perform a visual inspection. Regularly check the cap on the nipple, inspect tires for the presence of objects protruding from the rubber. And if in the first case, the nipple just clogged with dirt and dust, in the second sortie foreign object from the tire and the pressure loss can lead to dangerous situations at speed.
You should also monitor the formation of bubbles and hernias. If they appear - hence violated the internal structure of tires and it should be replaced. From the winter tires in no case shall hang any objects, construction details, interior metal wire. Even in the absence of external damage the tire can be represent a hazard if it is heavily abraded and worn.
Reducing the depth and clarity of drainage grooves leads to a decrease in handling on wet surfaces. Increases the effect of aquaplaning, lost contact with the road. In addition, the worn tire is easier to pierce.
Also, should periodically check the level of pressure in the tires. It must correspond to the normalized recommended by the manufacturer. Check your blood pressure only in the cooled tire, because the pressure in the heated while riding buses increases.
Too much inflated tires contribute to the rigidity of the vehicle, increasing the load on the suspension, themselves wear unevenly. In addition to all the contact patch with the coating decreases, which reduces and manageability. A small tire pressure increases the chance of breakdown of the tire, and can also damage the disc.
Tire storage implies the absence of atmospheric effects on the gums, direct sunlight. It is best to pack a tire in plastic bags - so tires remain the best way.
