Why uneven tires on the wheel. How to restore elasticity to hardened rubber (rubber product), is it possible? What is needed to restore the elasticity of rubber

Deformation- this is a change in the size or shape of a solid under the influence of external forces. When applied to tires, two types of deformations can be distinguished:

• Functional deformation;
• Critical deformation.

Functional deformation is one of the responsibilities that a modern tire must perform. Namely - to deform, reducing the vibration and noise impact on the car and the driver, which occurs when the tire rolls on the road surface. The flexibility of the tire structure, as well as the correct pressure inside, allows the tire to perform this function without any problems, while making a huge number of deformations per unit of time without negative consequences.

Critical deformation it is precisely characterized by the fact that its consequence can be a complete or partial destruction of the tire, which excludes its further use. Critical deformations include:

Warehouse;

Arising from prolonged standing of the car;

As a result of driving at a pressure lower than recommended;

Shock with the destruction of the sidewall.

Deformation of the tire due to improper storage

The damage that a tire receives when the tire storage rules are violated is a fairly common operational damage that is not a consequence of the tire performing its functions. Among this type of critical deformations, the following tire damage occurs:

- bead ring fracture caused by long-term storage of herringbone tires. Unfortunately, storage in this manner is a very common practice, although tire manufacturers only recommend using it for a limited amount of time to transport tires. A broken bead ring is a non-repairable defect, and it is not recommended to install such tires on rims.

How to avoid:

It is necessary to carefully inspect new tires upon receipt: The bead rings of the tire must have a strict round shape with no minimum breakage. In addition, during long-term storage, it is recommended to put the tires on the tread, in an upright position, using special racks that do not damage the tires.

- curvature of the tire when stored in stacks ... This storage method is still common, and is also particularly hazardous for tires at the bottom of the stack. And the higher this structure, the more the lower tires suffer. This storage can lead to internal bending of the tire, which in turn can cause the tire to slip to the side, as well as unregulated imbalance or vibration.

How to avoid:

Buy tires at and avoid those stores where there are a lot of tire stacks (more than four tires in height) in the sales area. Since the internal curvature of the tire cannot be seen by visual inspection, only a balancing machine will help to identify the first signs of a problem with the tire. When storing tires by the owner, it is also necessary to avoid storing in a pile, even if the number of tires is limited to four.

Deformation of the tire resulting from prolonged standing of the car

Few people know that tires can be damaged and from a long stay in an upright position, with air inside. As a rule, this is possible when the car is parked in one place. This position deforms the tire, depriving it of its perfectly round shape. When driving on such a tire, vibrations and noise may appear. Irrepairable damage to the internal structure of the tire is also possible, especially in tires that have been in service for a long time before.

How to avoid:

The technical documents recommend limiting the duration of such a long stay to two days for fully loaded vehicles and up to ten days for unloaded vehicles. If longer parking is required, reduce the load on the tires by using stands or moving the vehicle.

Deformation of the tire due to driving at low pressure

One of the most common forms of critical deformation is irreversible tire change, which occurs due to the operation of the tire with low internal pressure. Due to this deficiency, the usual working deformations become superfluous, and the tire walls, which are not designed for excessive bending, begin to heat up excessively. Thus, the destruction of the tire itself begins. First, the sealing layer is destroyed: it begins to bulge on the inner surface of the joint of the sidewall and the treadmill, then it peels off, and a rubber grout is formed. Then the sidewall, exposed to the threads of the carcass, begins to crack, and air leaves the tire. Further driving on such a tire can lead to complete separation of the sidewall from the tread.

How to avoid:

Monitor pressure. In addition to checking, you need to regularly change the valves, timely and efficiently repair tires, and avoid riding on damaged tires. Since all this can lead to a slow loss of pressure and to the appearance of a critical deformation of the tire.

Deformation of the tire under shock shock loading

At hitting a tire in a pit, hitting a foreign object on the road may cause tire deformation, which can destroy the product at one time. If this happens at high speed, and the edges of the pit or object are hard and sharp enough, the chances of instant tire rupture are greatly increased. In such a situation, the tire sidewall is pinched between the disc and the surface, for example, in pits. The impact of other factors (speed, aggressiveness of the obstacle) leads to the appearance of an impact force, which breaks several threads of the frame. The weakened sidewall of the tire is easily deformed by internal pressure, and a hernia appears. Further use of the tire is not recommended... It should be noted that sometimes the rupture of the carcass threads is accompanied by the rupture of the inner and outer layers of the tire sidewall, leading to a loss of pressure, which, of course, excludes further tire repair and use.

How to avoid:

Carefully, while slowing down, drive through sections of the road with poor coverage, do not run over curbs and other foreign objects. If bad roads are a fairly common occurrence, then it will not be superfluous to pay attention to technologies that protect tires from damage. For example, Michelin uses IronFlex technology for some of its models (, X-Ice North 3, X-Ice 3), which reduces the likelihood of tire sidewall damage from shock deformation. For the same purpose, a double carcass is used for off-road tires of the family, which also reduces the likelihood of premature tire out of service due to damage to the carcass threads.

As soon as the tire workers did not explain this sad fact. But all the "expert comments" usually boiled down to one thing: the owner of the car is to blame - he carelessly drives on uneven roads; overloads the car, does not monitor wheel alignment, tire pressure, balancing ...

A conscientious motorist, having read or heard something like that, is surprised: “I follow the pressure, I don’t overload the car, the alignment camber and balancing are in order… As for the“ carelessness ”, I didn’t bend even flimsy iron disks! And still I lost count of crooked tires. and 25 thousand were not nursed - the protector is still anywhere, but it is impossible to drive. By the way, gentlemen, tire workers, why does this almost never happen with the products of your foreign competitors? "

Let us first of all remember why a tire - unlike, for example, a tube - retains its size and shape, even if it is inflated? Because, as everyone knows, it is not made only of rubber! The almost inextensible cord carcass largely determines the strength, wear resistance, mechanical rolling losses and a number of other important properties of the tire.

The modern radial tire (Fig. 1) owes its name to the fact that the cords of the main (from side to side) carcass 1 are located in radial planes and do not intersect, as in the previous, diagonal ones. This cord is usually textile.

The crown zone of the tire, experiencing increased loads, is additionally reinforced by a power ring - a metal cord breaker 2. Its cord threads are cables twisted from several steel wires, with a brass coating for better adhesion, not radially laid, but at a certain angle to the plane of rotation of the wheel in several layers. The design resembles a mesh.

Its width almost corresponds to the tread, the ends of the threads are free - not tied to anything. But after vulcanization, the belt is practically inextensible, although it is flexible enough. This allows the tire to roll normally. Such tires consume less energy (that is, fuel) for this, the car with them is more manageable, their tread lasts longer, etc. But all these advantages are easily crossed out by one drawback. It is necessary to break the bonds between the cord and the rubber - and the breaker bends. The tire, they will say, went with a screw. And then, even with a very decent tread, there is nothing left but to part with it.

BEGINNING OF THE END

Destruction of a tire hurts the car owner's pocket. Noticing that the car began to wiggle at low speed, an experienced motorist will become sad. It will stop and examine the wheels. This is the reason: one of the tires seemed to be skewed!

Let's take an example. An openwork bicycle wheel (Fig. 2) with thin spokes, however, has sufficient strength and stable shape ... only under certain conditions, when all the spokes of the same length and equally loaded (Fig. 2a). (We will not consider more complex schemes here.) If at least one or two spokes have burst, the symmetrical balance of forces is violated (Fig. 2b). Loads will begin to redistribute, serviceable spokes pull the hub towards them, the wheel changes shape until a new balance of forces occurs. But now the spokes near the broken ones are heavily overloaded. And in turn they can burst. The wheel deforms even more.

Roughly the same happens if the cord breaks. Or flakes off the rubber and "creeps". Such a tire is unusable. It becomes a source of unrecoverable shaking (the naive try to "balance" it, not taking into account that the wheel of an irregular shape, even balanced, still shakes!), The curvature progresses, the tire collapses faster and faster, and this can end in an explosion on the go! (Typically, a jolted car enthusiast throws out the tire much earlier.)

RISK FACTORS

Many people do not even suspect that a single puncture often ruins a steel cord tire if dirty, salty water gets into the hole. As a rule, this happens to those who prefer wheels with cameras. We got used to acting like this: to glue the camera and not think about the tire - well, what will it do! By the way, even a textile cord can "rot" in its own way. And metal - even more so. Often, after a year, only rust reminds of the wires near the puncture site. ("Opening" such a tire and carefully cutting the tread to the cord, it is easy to be convinced of this.). The breaker, which has lost a part of the cord, will bend without fail - we have already named the reasons. The moral is simple: it is advisable to seal any puncture of a tire, although, of course, this is unnecessary trouble.

Another risk factor is air pressure. It is in the owner's interest to keep an eye on him. Low (most often the wheels are lowered at a bummer!) Not only increases fuel consumption, reduces speed, etc., but also accelerates tire wear, in particular, the carcass and broker cord, which in a crumpled tire (Fig. 3) additionally "breaks down "and suffers more from fatigue. In addition, when a tire is under-inflated, much more heat is generated - additional energy is spent on its deformation (and on internal friction between the layers of rubber). The tire heats up intensively, and when the temperature inside, between the layers, "rolls over" beyond 120 ° C and crawls further, irreversible damage cannot be avoided. The strength of the cord, especially the textile cord, is sharply reduced, the bonds are destroyed, the tire delaminates.

The next enemy of a steel-cord broker is a strong blow concentrated on a small area. If you hit a sharp stone at full speed, the pluses of the steel cord become minuses: the high modulus of elasticity of steel does not allow the wires to stretch a little for a moment, to smooth out the impact. And weakened by corrosion or wear, they can simply burst.

By the way, what kind of wear are we talking about? From the "killed" tire, with wires sticking out from under the tread, remove one with pliers. And take a closer look. It looks like a thin "gimbal"! Worn out by friction on adjacent ones. Let's count how many revolutions does the "Zhiguli" wheel make per kilometer of track? About 600. And for 10 thousand? .. The account went into the millions? That's how many times, at least, the wire has moved, rubbed against the neighboring ones! We are not talking about the unevenness of the road that increase this score ...

This means that, like the car as a whole, the "old" tire is weaker than the new one and needs to be treated more carefully. The fact that a new one does not care, a two-year-old - even with a seemingly good tread - will easily finish off. And do not forget about latent corrosion: some damage to the tire - in the form of deep cuts - expose the cord, but the owner does not even know about them, since there is no through hole.
In a word, those who are not spoiled by extra money should be attentive to the surprises of our roads. I drove onto a broken surface - immediately slow down. I saw a scattering of bottle shards - try not to run over. And if you hit it, check the tires: are they intact, are pieces of glass sticking out of the tread? Removing them in time is sometimes to save the tire.

Gennady Ivanov "The process has begun ..."
The magazine "Behind the wheel", 2002 №3

Tires are one of the most prone to wear and tear in a car. But what if they wear out unevenly. First, you need to correctly identify this uneven tire wear in order to determine its causes. Exactly how the rubber wears out unevenly:

• in various places of the circle - at certain points of the tread it is worn out strongly (spots),
• on different side of the tire - the outer, inner side of the tire or its central area along the entire circumference,
• one tire wears out much faster than the rest,
• a pair of front or rear tires deteriorate more quickly.

Let's now give the reasons and consider the pattern of tire wear for each cause. Let us consider these reasons from the most common to the least common.

The tire is worn in the center or on the sides. Cause - insufficient or excessive tire pressure

Incorrectly exposed will certainly lead to the fact that their abrasion is uneven. It is a waste of time to try to identify this cause by specific worn out wheels. The pressure can change in each wheel in different ways, even if you always inflate only all four wheels.

But this reason can be determined by the nature of the wear of the tread itself. The fact is that an under-inflated tire, as you know, sags, and therefore the sides of the working surface wear out faster. But the pumped-over tires wear out faster, on the contrary, the central part, since with excess pressure it is this pressure that pushes out the most, as a result of which the most of the load falls on the axis of the circle.

The result of riding on inflated (top) and under-inflated (bottom) tires

Only certain areas of the tire are worn out. The reason is a deformed disc or imbalance of the wheels

A deformed (dented, "figure eight", etc.) disc can also often cause uneven rubber wear. In this case, wear will occur in certain places (spots) of the tread. If the disc is "eight", then the wear will be in the form of two spots: one on one side of the tire in a certain place, and the second - in a diametrically opposite place of the tire and on the opposite side. When the disc deforms, the tire wears out very quickly, depending on the degree of deformation, of course.

The tire is subject to similar wear in the case of wheel unbalance. Although, this happens much more slowly than with a deformed disk.

And in both cases, an additional symptom is beating on the steering wheel or throughout the car. A visual inspection of a worn wheel will help identify this deformation.

Sometimes the cause of increased wear can be the rubber itself - its marriage in the form of a burst metal cord. The cord may burst if the rubber is already significantly worn out.

Only the inside or outside of the front wheels is worn out. The reason is wheel alignment

If the front wheel alignment is out of order, it means that your two front wheels are not parallel to each other. They either "clubfoot" - they look forward, slightly to the center by the projection of the direction, or are inclined to one side or the other relative to the vertical axis.

As a result, you get excessive wear on the rubber only on the front wheels, either on the inside or on the outside.

If a similar situation has occurred with the rear wheels, then there is a bent beam (if any) or one of the failed (possibly also bent) suspension elements.

The outer side of the tires can also wear out due to a faulty silent block or ball.

Only one wheel wears out. Cause - something happened in the suspension or the brakes wedge

If any component in your suspension is worn or weakened, such as a leaking strut, this can lead to excessive wear on the tires on that particular wheel. If any part of the suspension is not working properly, the wheel will bounce more or it will harder to pass bumps in the road. This creates additional friction on this tire, which causes a significant reduction in tire life and tread condition.

Here, as a rule, uniform wear occurs only on the tires on only one wheel.

Now imagine that you are driving around all day with a little brake on your foot. This is what it is like if a brake component such as a caliper (its piston) wedges. This usually only happens on one wheel, and because of this it wears out faster (even wear occurs).

Only the front wheels are worn out. Cause - something happened in the helmsman

Almost every part of the steering system can also cause tire wear. But here we will only talk about the front wheels, and the nature of the wear can be completely different: both spots and on one side of the tire along the entire circumference of the tread.

Rubber is used in many household structures: various hoses, seals, adapters, car parts. Over time, products made from this material fail, dry out, lose elasticity, and become inconvenient to use. It is not worth buying new elements right away, you can try to soften the rubber at home.

Reconditioned rubber part using kerosene method

Under the influence of external factors, rubber elements lose their original properties, become less elastic, and harden. Their further use will not bring the desired effect, seals, for example, will not be able to make the system completely sealed. Buying new rubber elements is sometimes difficult due to the lack of products of the required size or their overpriced.

The following substances allow to soften rubber:

1. Kerosene. Allows you to make rubber parts soft by affecting the structure of the material. After processing, the rubber element is fully elastic. The recovery technology is as follows:

• fill a small container with kerosene (choose the size of the container depending on the size of the product to be restored);
• place the part in a container with kerosene for 3 hours;
• after the specified time, check the product for softness, if the result is satisfactory: remove the material and rinse with warm running water;
• dry the material in a natural way, without using a hair dryer or battery.

1. Ammonium alcohol. The process of restoring old material is as follows:

• dilute the indicated alcohol with water in a ratio of 1: 7;
• place the rubber material in the resulting solution for half an hour;
• after the specified time, remove the part and rinse with warm running water;
• allow parts to dry completely before using.

Please note: you cannot keep rubber in a solution of ammonia and water for more than an hour. If the material does not become elastic after 30 minutes, use a different recovery method.

1. Rubbing alcohol followed by glycerin. Reanimation technology for rubber parts:

• fill the container with medical alcohol;
• place in alcohol the part that needs to be restored for several hours;
• after the specified time, check the condition of the product, if it is soft enough, remove the element from the solution and wash it with warm soapy water;
• rub glycerin into the surface of the part using a sponge (cloth);
• remove the remaining glycerin from the surface of the product.

Instead of glycerin, it is allowed to use automotive oil, it is rubbed into the surface of the product, then the parts are kept for half an hour before use. During this period, the rubber becomes sufficiently elastic.

1. Castor oil and silicone. Let's make a reservation right away - this method allows you to quickly "reanimate" old rubber, but the recovery effect will not last long, after a few days the product will become hard. For the specified method, follow the sequence:

• smear the part with silicone;
• wait 10 minutes;
• after the specified time, the part can be used.

Note that a similar effect is achieved with castor oil. It is rubbed into the surface of the part, after which it becomes soft and elastic.

Heating is an effective method

There are situations when a rubber element, due to its hardening, is difficult to remove from structural parts. To achieve the desired result, you can heat the rubber with a stream of hot air using a hair dryer. When exposed to high temperature, the material will become softer, it will be possible to pull it off the part.

Too "hardened" element is softened by boiling in salted water. The technology is as follows:

• fill the container with salted water;
• let the liquid boil;
• place the rubber element in boiling water for 10 minutes;
• remove the rubber and quickly use it for its intended purpose.

This method is quite effective, but has a short-term effect. Cooling down, the rubber will become hard again.

Conclusion

You can soften the rubber using the methods described above. In this case, it is necessary to take into account: a long-term effect after recovery, has a method with kerosene. Rubber, after its application, remains soft and elastic for a long time, because the structure of the material changes. Other methods do not allow you to achieve this result.

From my own experience I know that not all rubber products can be restored, i.e. give them their former elasticity and softness, after it has become callous. In general, a small part of rubber can be brought back to life if we are talking specifically about rubber, and not about the latest polymers, which do not lose their physical properties at a certain operating temperature.

The only difference is that rubber products, namely the material "rubber" itself, undergo a process such as vulcanization in the process of their manufacture, when the base of the rubber - rubber - turns into rubber when interacting with certain substances at a certain temperature. Rubber was a new material in which rubber molecules created a single spatial network, it is due to this single mesh that rubber has its own physical properties.

It will not be practical to talk about all rubber products in one recommendation, since there are a lot of rubber types and each rubber has its own intrinsic properties, as well as the degree of rubber saturation, the ability to crystallize and orientation, the strength of the chemical bond chain and the flexibility of macromolecules.

There are 5 main factors that affect aging and loss of elasticity:

• light exposure, in which an irreversible process of photo-oxidation of rubber occurs.
• ozone exposure, which results in cracking of stressed rubber.
• thermal effect destroys the spatial grid.
• radiation exposure destroys the bond of molecules.
• vacuum action tears apart individual areas in the product.

All this negative influence leads to the fact that the rubber becomes hard and / or brittle. If the product crumbles, then it will not work to give it elasticity, since the bond between the molecules is broken.

But if the rubber has become hardened, but has not begun to deteriorate, then it can be brought back to life.

One of the misconceptions is that many advise to dip or spray on the product with solvents, gasoline or alcohol. This cannot be done, since, firstly, there is oil-petrol-resistant rubber, which simply will not accept these liquids, and secondly, other rubber products simply dissolve partially or completely in these solvents, and the elasticity effect will only be temporary.

But one of the actually effective solutions that can "revive" rubber products is ammonia solution with 5% concentration.

In this solution, the product should be held for no more than 15 minutes, then, if possible, knead it by mechanical pressure and process it with the following composition.

After softening, place the product in water-glycerin solution with 5% concentration.

The product must also be held in this solution for no more than 15 minutes.

The temperature of the solutions should be in the range of 40-50 degrees.

There should not be a long time between the two solutions, since ammonia destroys rubber with prolonged exposure, and glycerin on water slows down this process.

Ammonia solution 5% is not on sale, for this reason you have to buy 10% and dilute it with distilled water according to the formula (see the chemical formulas, I personally can make a mistake)

A 5% water-glycerin solution is also not commercially available, there is only pure glycerin or 85%, it must also be diluted to obtain the appropriate concentration.