The car turns on the wheel

The wheel is a very important and usually underestimated element of a car. It is through the rim and tire that the car touches the road, so these components directly affect the driving performance of the car and our safety. It is worth getting acquainted with the structure of the wheel and its parameters in order to use it consciously and not make mistakes during operation.

In general, a car wheel is quite simple - it consists of a high-strength rim (rim), usually integrally connected to the disk, and. The wheels are connected to the car most often with the help of bearing hubs. Thanks to them, they can rotate on the fixed axles of the car's suspension.

The task of rims made of steel or aluminum alloy (usually with the addition of magnesium), forces are also transferred from the wheel hub to the tire. The tire itself is responsible for maintaining the correct pressure in the wheel, the reinforced bead of which fits snugly against the wheel rim.

Modern pneumatic tire it consists of many layers of different rubber compounds. Inside there is a base - a special construction of rubberized steel threads (cords), which strengthen the tires and give them optimal rigidity. Modern radial tires have a 90-degree radial cord that provides stiffer tread, more sidewall flexibility, lower fuel consumption, better grip and optimum cornering behavior.

History wheel

Dunlop's first pneumatic tire.

Of all the inventions that were used in the car, the wheel has the oldest metric - it was invented in the middle of the XNUMXth millennium BC in Mesopotamia. However, it was quickly noticed that the use of leather upholstery around its edges allowed for lower rolling resistance and minimized the risk of potential damage. So the first, most primitive tire was created.

A breakthrough in wheel design did not come until 1839, when he invented the rubber vulcanization process, in other words, he invented rubber. Initially, tires were made entirely of rubber, known as solids. However, they were very heavy, awkward to use, and spontaneously ignited. A few years later, in 1845, Robert William Thomson designed the first pneumatic tube tire. His invention, however, was underdeveloped and Thomson did not know how to properly advertise it, so it did not catch on in the market.

Wire spoke wheels

The first winter tire Kelirengas

Four decades later, in 1888, Scotsman John Dunlop had a similar idea (somewhat by accident when he was trying to improve his 10-year-old son's bike), but he had more marketing skills than Thompson and his design took the market by storm. Three years later, Dunlop had serious competition with the French company of the brothers Andre and Edouard Michelin, who significantly improved the design of the tire and tube. Dunlop's solution had the tire permanently attached to the rim, making it difficult to access the inner tube.

Michelin connected the rim to the tire with a small screw and clamps. The structure was solid, and damaged tires changed very quickly, which was confirmed by the numerous victories of cars equipped with Michelin tires at the rallies. The first tires resembled today's slicks, they had no tread. It was first used in 1904 by the engineers of the German company Continental, so it was a big breakthrough.

Michelin X - the first radial tire

The dynamic development of the tire industry has made the rubber milk needed in the vulcanization process as expensive as gold. Almost immediately, the search began for a method for the production of synthetic rubber. This was first done in 1909 by Bayer engineer Friedrich Hofmann. However, only ten years later, Walter Bock and Eduard Chunkur corrected Hofmann's overly complex "recipe" (added, among other things, butadiene and sodium), thanks to which Bona synthetic gum conquered the European market. Abroad, a similar revolution took place much later, only in 1940, the scientist Waldo Semon from BFGoodrich patented a mixture called Ameripol.

The first cars moved on wheels with wooden spokes and rims. In the 30s and 40s, wooden spokes were replaced by wire spokes, and in the following decades, spokes began to give way to disc wheels. As the tires were used in a variety of climates and road conditions, specialized versions such as the winter tire quickly emerged. The first winter tire called Kelirengas ("Weather tire") was developed in 1934 by the Finnish Suomen Gummitehdas Osakeyhtiö, a company that later became Nokian.

Immediately after World War II, Michelin and BFGoodrich introduced two more innovations that completely changed the tire industry: in 1946, the French developed the world's first Michelin X Radial Tireand in 1947 BFGoodrich introduced tubeless tires. Both solutions had so many advantages that they quickly became widely used and dominate the market to this day.

The core, that is, the rim

The part of the wheel on which the tire is mounted is usually called the rim. In fact, it consists of at least two components for different purposes: the rim (rim), on which the tire directly rests, and the disc, with which the wheel is attached to the car. However, at present, these parts are inseparable - welded, riveted or most often cast in one piece from an aluminum alloy, and the working disks are made of lightweight and durable magnesium or carbon fiber. The latest trend is plastic discs.

Alloy wheels can be cast or forged. The latter are more durable and resistant to stress and are therefore excellently suited, for example, to rallies. However, they are much more expensive than the usual "alluses".

If only we can afford it it is best to use two sets of tires and wheels - summer and winter. Constant seasonal tire changes can easily harm them. If for any reason we need to replace the discs, it is easiest to use factory discs, in case of replacement it is necessary to adjust the pitch of the screws - only minor differences compared to the original are allowed, which can be corrected with the so-called floating screws.

It is also important to install a rim, or offset (ET marking), which determines how much the wheel will hide in the wheel arch or go beyond its outline. The rim width must match the tire size i.

Tire without secrets

The key and most versatile element of a wheel is the tire, which is responsible for keeping the car in contact with the road, allowing it to transfer of driving force to the ground i effective braking.

The modern tire is a complex multilayer structure.

At first glance, this is an ordinary piece of profiled rubber with a tread. But if you cut it across, then we see a complex, multilayer structure. Its skeleton is a carcass consisting of a textile cord, the task of which is to maintain the shape of the tire under the influence of internal pressure and transfer the load during cornering, braking and acceleration.

On the inside of the tire, the carcass is covered with a filler and a butyl coating that acts as a sealant. The carcass is separated from the tread by a steel stiffening belt, and in the case of tires with high speed indexes, there is also a polyamide belt immediately under the tread. The base is wound around the so-called bead wire, thanks to which it is possible to firmly and tightly fit the tire onto the rim.

Tire parameters and characteristics, such as cornering behavior, grip on various surfaces, road dino, compound and tread used have the greatest impact. According to the type of tread, tires can be divided into directional, block, mixed, pulling, ribbed and asymmetric, the latter being the most widely used today due to the most modern and versatile design.

The outer and inner sides of the asymmetric tire have a completely different shape - the first is formed into massive cubes that are responsible for driving stability, and smaller blocks located on the inside disperse water.

In addition to blocks, another important part of the tread is the so-called sipes, i.e. narrow gaps that create gaps inside the tread blocks, providing more efficient braking and preventing slipping on wet and snowy surfaces. This is why the sipe system in winter tires is more extensive. In addition, winter tires are made from a softer, more flexible compound and offer the best performance on wet or snowy surfaces. When temperatures drop below about 7 degrees Celsius, summer tires harden and braking performance is reduced.

When buying a new tire, you will definitely come across the EU Energy Label, which has been mandatory since 2014. It describes only three parameters: rolling resistance (in terms of fuel consumption), the behavior of the "rubber" on a wet surface and its volume in decibels. The first two parameters are designated by letters from "A" (best) to "G" (worst).

The EU labels are a kind of benchmark, useful for comparing tires of the same size, but we know from practice that they should not be trusted too much. It is definitely better to rely on independent tests and opinions available in the automotive press or on the Internet portals.

More important from the user's point of view is the marking on the tire itself. and we see, for example, the following sequence of numbers and letters: 235/40 R 18 94 V XL. The first number is the width of the tire in millimeters. "4" is the tire profile, i.e. the ratio of height to width (in this case it is 40% of 235 mm). "R" means it's a radial tire. The third number, “18”, is the diameter of the seat in inches and should match the diameter of the rim. The number "94" is the tire's load capacity index, in this case 615kg per tyre. “V” is the speed index, i.e. the maximum speed at which a car can travel on a given tire with a full load (in our example it is 240 km/h; other limits, for example, Q - 160 km/h, T - 190 km/h, H - 210 km/h) . "XL" is the designation for a reinforced tire.

Down, down and down

When comparing cars made decades ago with modern ones, we will surely notice that new cars have larger wheels than their predecessors. The rim diameter and wheel width have increased, while the tire profile has decreased. Such wheels certainly look more attractive, but their popularity is not only in design. The fact is that modern cars are getting heavier and faster, and the demands on brakes are increasing.

The low profile results in a large tire width.

Tire damage at highway speeds will be much more dangerous if a balloon tire bursts - it is very easy to lose control of such a vehicle. A car on low-profile tires will likely be able to stay in the lane and brake safely.

The low bead, reinforced with a special lip, also means greater rigidity, which is especially valuable in the case of dynamic driving on winding roads. In addition, the vehicle is more stable when driving at high speeds and brakes better on lower and wider tires. However, in everyday life, a low profile means less comfort, especially on bumpy city roads. The biggest disaster for such wheels are pits and curbs.

Watch the tread and pressure

Theoretically, Polish law allows driving on tires with 1,6 mm tread remaining. But using such "chewing gum" is a hassle. The braking distance on wet surfaces is then at least three times longer, and it could cost you your life. The lower safety limit is 3 mm for summer tires and 4 mm for winter tires.

The aging process of rubber progresses over time, which leads to an increase in its hardness, which, in turn, affects the deterioration of grip - especially on wet surfaces. Therefore, before installing or buying a used tire, you should check the four-digit code on the sidewall of the tire: the first two digits indicate the week, and the last two digits indicate the year of manufacture. If the tire is more than 10 years old, we should not use it anymore.

It is also worth assessing the condition of the tires in terms of damage, as some of them exclude tires from service even though the tread is in good condition. These include cracks in the rubber, lateral damage (punctures), blisters on the side and front, severe bead damage (usually associated with damage to the edge of the rim).

What shortens tire life? Riding with too little air pressure accelerates tread wear, suspension play and poor geometry cause serrations, and tires (and rims) are often damaged when climbing curbs too quickly. It is worth systematically checking the pressure, because an under-inflated tire not only wears out faster, but also has worse grip, resistance to aquaplaning and significantly increases fuel consumption.

Opona Driveguard - Bridgeston Treadmill

Since 2014, the TPMS, Tire Pressure Monitoring System, has become a mandatory equipment for all new cars, a system whose task is to constantly monitor tire pressure. It comes in two versions.

The intermediate system uses ABS to control tire pressure, which counts the speed of rotation of the wheels (an underinflated wheel spins faster) and vibrations, the frequency of which depends on the stiffness of the tire. It is not very complicated, it is cheaper to buy and maintain, but it does not show accurate measurements, it only alarms when the air in the wheel runs out for a long time.

On the other hand, direct systems accurately and continuously measure the pressure (and sometimes temperature) in each wheel and transmit the measurement result by radio to the on-board computer. However, they are expensive, increase the cost of seasonal tire changes, and worse, are easily damaged in such use.

Tires that provide safety even with serious damage have been worked on for many years, for example, Kleber experimented with tires filled with gel that sealed a hole after a puncture, but only tires gained wider popularity in the market. The standard ones have a reinforced sidewall, which, despite the pressure drop, can support the weight of the car for some time. In fact, they increase safety, but, unfortunately, they are not without drawbacks: the roads are noisy, they reduce driving comfort (reinforced walls transmit more vibrations to the car body), they are more difficult to maintain (special equipment is needed), they accelerate the wear of the suspension system.

специалисты

The quality and parameters of rims and tires are of particular importance in motorsport and motorsport. There's a reason a car is considered as off-road as its tires, with racers referring to tires as "black gold".

Pirelli tire set for F1 for the 2020 season

Mud Terrain off-road tire

In a racing or rally car, it is important to combine high levels of wet and dry grip with balanced handling characteristics. The tire should not lose its properties after the mixture is overheated, it should retain grip during skidding, it should respond instantly and very accurately to the steering wheel. For prestigious competitions such as WRC or F1, special tire models are being prepared - usually several sets designed for different conditions. Most popular performance models: (no tread), gravel and rain.

Most often we come across two types of tires: AT (All Terrain) and MT (Mud Terrain). If we often move on asphalt, but at the same time do not avoid mud baths and crossing sand, let's use fairly versatile AT tires. If high resistance to damage and the best grip is a priority, it is better to buy typical MT tires. As the name suggests, they will be unbeatable, especially on muddy soil.

Smart and green

The tires of the future will be increasingly environmentally friendly, intelligent and tailored to the individual needs of the user.

The steering wheel of the car of the future - Michelin Vision

There were at least a few ideas for "green" wheels, but such bold concepts as Michelin and, probably, no one imagined. Vision by Michelin is a fully biodegradable tire and rim in one. It is made from recyclable materials, does not require pumping due to its internal bubble structure, and is manufactured in.

Goodyear Oxygene green tire covered with moss on the side

Michelin even suggests that cars of the future will be able to print their own tread on such a wheel, depending on the needs of the user. In turn, Goodyear created Oxygene tires, which are green not only in name, because their openwork sidewall is covered with real, living moss that produces oxygen and energy. The special tread pattern not only increases traction, but also traps water from the road surface, promoting photosynthesis. The energy generated in this process is used to power sensors embedded in the tire, an artificial intelligence module and light strips located in the sidewall of the tire.

Construction of the Goodyear reCharge tire

Oxygene also uses visible light or a LiFi communication system so it can connect to the Internet of Things for vehicle-to-vehicle (V2V) and vehicle-to-urban (V2I) communications.

and a rapidly growing ecosystem of interconnected and constantly exchanging information, the role of the car wheel must be redefined.

The car of the future itself will be an integrated system of "smart" mobile components, and at the same time it will fit into the more complex communication systems of modern road networks and.

At the first stage of using intelligent technologies in the design of the wheel, the sensors placed in the tires will perform various types of measurements, and then transmit the collected information to the driver through the on-board computer or mobile device. An example of such a solution is the ContinentaleTIS prototype tire, which uses a sensor connected directly to the tire's lining to measure tire temperature, load, and even tread depth and pressure. At the right time, eTIS will inform the driver that it is time to change the tire - and not by mileage, but by the actual condition of the rubber.

The next step will be to create a tire that, without the need for driver intervention, will respond adequately to the data collected by the sensors. Such wheels will automatically inflate or retread a flat tire, and over time will be able to dynamically adapt to weather and road conditions, for example, when it rains, drainage grooves treads expand in width to reduce the risk of aquaplaning. An interesting solution of this type is a system that allows you to automatically adjust the pressure in the tires of moving vehicles using microcompressors controlled by a microprocessor.

Michelin Uptis czyli Unique anti-puncture tire system

The smart bus is also a bus that is individually adapted to the user and his current needs. Let's imagine that we are driving on a highway, but we still have a difficult off-road section at our destination. Thus, the requirements for tire properties vary greatly. Wheels such as the Goodyear reCharge are the solution. In appearance, it looks standard - it is made of a rim and a tire.

The key element, however, is a special reservoir located in the rim containing a capsule filled with a custom biodegradable mixture, allowing the tread to be regenerated or adapted to changing road conditions. For example, it might have an off-road tread that would allow the car in our example to drive off the highway and into the lot. In addition, artificial intelligence will be able to produce a completely personalized mixture adapted to our driving style. The blend itself will be made from biodegradable biomaterial and reinforced with fibers inspired by one of the hardest natural materials in the world - spider silk.

There are also the first prototypes of wheels, which radically change the design solutions that have been used for more than a hundred years. These are models that are completely puncture and damage resistant and then completely integrate the rim with the tire.

A year ago, Michelin introduced the Uptis, a puncture-resistant airless model that the company plans to release in four years. The space between the traditional tread and the rim is filled with an openwork ribbed structure made from a special blend of rubber and fiberglass. Such a tire cannot be punctured because there is no air inside and it is flexible enough to provide comfort and at the same time maximum resistance to damage.

Ball instead of wheel: Goodyear Eagle 360 ​​Urban

Perhaps the cars of the future will not go on wheels at all, but on ... crutches. This vision was presented by Goodyear in the form of a prototype Eagle 360 ​​Urban. The ball should be better than a standard wheel, dampen bumps, increase the vehicle's cross-country ability and cross-country ability (turning on the spot), and provide greater durability.

Eagle 360 ​​Urban is wrapped in a bionic flexible shell full of sensors with which it can monitor its own condition and collect information about the environment, including road surface. Behind the bionic "skin" is a porous structure that remains flexible despite the weight of the vehicle. Cylinders located under the surface of the tire, acting on the same principle as human muscles, can permanently form individual fragments of the tire tread. Besides Eagle 360 ​​Urban it can repair itself - when the sensors detect a puncture, they rotate the ball in such a way as to limit the pressure on the puncture site and cause chemical reactions to close the puncture!