Timing of four rounds

Generally, the position changes every 5,000km ~ 10.000km

Advantages of transposition

-Can preventtireIrregular wear, extending tire life.

-Abnormal wear caused by incorrect positioning can be found.

-Easy to repair when the tire is punctured

generallycarThe engine is at the front and the driver’s seat is also at the front, so the front is more stressed than the rear. Functionally, when the vehicle stops or starts (front-wheel drive), the front wheels first rub against the ground, so the front wheels are more powerful than the rear. Wheels wear quickly. In order to evenly wear the front and rear wheels, Hankook Tire recommends: Exchange the positions of the front and rear wheels after driving 10,000Km.

Tire replacement period

To help users know when to replace old tires with new tires, some wear marks are marked on the tires. These bar marks are located in the tread grooves, and the sidewalls are indicated by ▲.

There are usually 6 ▲ marks on a tire. If the above-mentioned tread surface and the strip mark in the groove (1.6mm high) are worn flat, the tire should be replaced.

Tire wear

In the case of using tires that exceed the wear limit,brakeIn the vehicle, because the tires of the vehicle are smooth, the braking distance is longer. If you use tires that exceed the wear limit, you cannot enjoy after-sales service. On rainy days, the drainage between the road and the tires is not good, and the tires may float on the water surface. Small scum on the road can also damage the tread surface, and accidents may occur.

The wear limit of snow tires

The method of expressing the wear limit of snow tires is different from that of ordinary 1.6mm tires. It is indicated by ↑. If worn to this place, the performance of snow tires will be lost, only the performance of ordinary tires. (Pattern depth: 1/2 of the entire groove depth)

The tire is a black, round rubber body, which is mounted on the car with the axle as the center. When the car is running normally, the tires rotate very quietly; when the car vibrates or noises, people feel that the tires are abnormal. As far as automobiles are concerned, tires are indeed rotating bodies with fixed shafts, but judging from the road on which the tires travel, the tires are not rotating, but contact and separation between a part of the tire and the ground often occur repeatedly. That is, the tire and the road continuously collide, and it is normal for the tire to collide with each other and shake at this time. Therefore, it can be said that vibration and noise of the running tires are normal.

Vibration and noise vary greatly according to tires and road conditions. In fact, most of the vibration and noise on the car body are the frame, engine and power transmission device. Let's take a look at how the tire itself is the cause of vibration and noise.

Vibration or noise occurs when the uniformity of the tire is not good. The uniformity here is broad, including the uniformity of weight, uniformity of size, and uniformity of rigidity.

Uneven weight

A tire is a collection of various materials such as rubber, cord, and toe wire. When the tire is divided into multiple small pieces, the weight of each piece will vary somewhat.

Uneven size

1) Radial deviation (RRO)

When the tire is regarded as a circle, if you draw a circle with a compass, it will become a true circle, but the circumference of a tire that is an assembly of rubber and a cord with a certain tension cannot be a true circle.

If you actually measure the circumference of the tire, it is not a true circle, and there are some unevenness on the circumference.

2) Lateral deviation (LRO)

When rotating the tire with one axis as the center, the deviation occurs from the left to right of the tire perpendicular to the direction of rotation.

Rigid, uneven, air-injected tires have to bear the weight of vehicles, cargo, and passengers during operation.Because of these weights, the parts in contact with the ground will be deformed. When the tire rotates once, all parts on the circumference of the tire will deform once in turn.

Assuming that the tire is composed of springs with different characteristics, the impact absorption force of each spring when contacting the ground is also different, and the force of each spring on the ground is also different. The difference between the maximum value and the minimum value in the amount of force variation of each part is called uneven rigidity.