Can the mended tire be put on the front wheel: talk about the mended tire

whether automobile tire repair affects safety depends on the repair method and location, and the risk may exist.

Automobile tires are ordinary vacuum tires, and tires without inner tubes are not only responsible for air tightness but also for stability. However, although the working strength is great, it does not mean that the strength will be affected after repair. Look at the picture:

As shown in the figure, the main component of the tire is high-quality rubber with carbon black, followed by steel wire layer, belt layer, cord layer and air-tight layer to strengthen the rubber structure, but the structures in different positions are obviously different.

The rubber layer at the crown is very thick, and the reinforcement layer is also complicated. The density of reinforcement is that the crown directly contacts the ground and needs frequent deformation and wear, so this layer must have a sufficiently stable structure. Similarly, the high structural strength and slight damage will not have obvious influence, even if it is pierced by a relatively thick nail. In the "tight" state of the cord and the belt, the rubber in this area can compress the foreign body even if the nail is not pulled out, and the deflation speed will be very slow.

Then the damaged area will be filled with adhesive tape or mushroom nail after the foreign matter is taken out, and the structure will still be stable under the action of "pulling force"; If mushroom nails or hot patching are used, the inner airtight layer can also be compensated, and the damaged tire eye will be directly integrated with the vulcanizing agent Roewe, and the tire strength is still very strong. Normal repair of the crown position will not affect the safety, and it will last for several years after three or five times of repair.

if the tire sidewall position is damaged, the repair process determines whether it will affect the safety, and other methods such as hot repair are not recommended.

The structure of the sidewall of the tire is very simple, with only a thin rubber layer, a cord layer and an airtight layer. As the tire is used as the first-stage shock absorption of the automobile, the sidewall can be made very thick for effective shock absorption, otherwise the subtle vibration will be directly transmitted to the body and the steering wheel. Only the original vehicle uses explosion-proof tires, except vehicles with targeted suspension upgrades.

once such a thin rubber layer is damaged, it is difficult to repair it, because the density of the cord is also low and its strength is not enough to "tighten", so as long as there is a hole, it will deflate instantly. And the sidewall will continue to "surge" during driving, as shown in point A in the following figure.

every time the wheel rotates, the point A will contact the ground once, and it will be deformed by the weight of the car body at the moment of contact, and then return to its original state after leaving the ground. When running at high speed, the wheels will be deformed frequently, which is similar to surge, so it is called surge phenomenon. If this position has been repaired and cold patching is used, the patch may cause glue opening under frequent surges, and it will leak slowly if it is not serious. If it is serious and it is driving, it may have a puncture, and the consequences are more serious.

Therefore, if the tire sidewall is just a tiny nail, it must be repaired with a hot patch. After the patch, it should be baked with a baking gun and pressed for more than 3 minutes. The principle is the same as that of hot patch for tire crown to fill holes and strengthen rubber layer. If the side wall is damaged too much, it can't be stable even with hot patching, so it is recommended to replace it directly.

The safety degree of tire patching is roughly the same as above, and the position of the repaired tire is not necessarily the driven wheel. "Low-speed front wheel puncture is more dangerous, and high-speed rear wheel puncture is more dangerous". The out-of-control rate of high-speed rear-wheel puncture vehicles exceeds 7%, and the huge lateral force generated at the moment of tire puncture can be intervened by the steering wheel, but there is no way for the rear wheel; The danger of low-speed front tire puncture mainly refers to the complicated road conditions, and the actual principle is the same as that of high-speed tire puncture.

Therefore, whether the mended tire should be put on the front wheel or the rear wheel depends on the main vehicle scene, and cannot be generalized. Personal opinion, for reference only.