How to choose wheels. Light alloy wheels Rating of firms and manufacturers
When the first joyful sensations from buying a car pass, when driving it becomes your daily work, it is at this moment that you face questions that you never thought about before. For example, how to choose the right wheels for your car, and specifically - car wheels.
Currently, the market represents a huge selection of car discs. Therefore, which disks and how to choose the right one sometimes becomes an insoluble task.
What discs are made?
There are several varieties: stamped, cast and forged wheels.
Stamped discs are the most common. They are made of ordinary steel, painted with enamel, usually in black or dark gray. The main advantage is that they are easy to repair. Always, with the ability, with the help of a simple tool, it is possible to return the shape of the disk. Of the minuses - they do not differ in the elegance of forms. You must have a set of stamped wheels, usually used with winter tires.
Alloy wheels are made from lightweight alloys, usually aluminum.
They have a different shape, and are lighter than stamped discs. This explains their popularity among experienced motorists. However, the high cost and, in practice, the impossibility of repair are a minus of this variety. We recommend that you buy if you are sure of careful driving and attentiveness on the road. And best used with summer tires.
How to choose an alloy wheel for a car?
The main alloys used in alloy wheels are aluminum, titanium, magnesium. Aluminum rims are light, strong and virtually corrosion resistant. Therefore, they are the most recommended for daily use. Magnesium alloy wheels are very susceptible to corrosion, so it is recommended to use them in warm and dry conditions, or permanently cover with an anti-corrosion coating. Titanium wheels belong to the elite group, so if you have a prestigious car or a sports car, and you plan to drive only in the city, choose titanium wheels.
Which is better - stamped or cast wheel? (video)
The next variety is forged wheels.
forged disc
The best and highest quality, but also the most expensive type. Made by hot stamping, they have high strength and low weight. Of the minuses - with a strong impact on an obstacle, it retains its shape, but there is a possibility of destruction of the wheel or cord, which leads to a complete replacement of the tire.
How to choose car wheels (video)
How to choose wheels on a car by size?
Usually, all information about the sizes of wheels and disks is indicated in the instructions for your car. Additionally (depending on the car) it can be indicated on separate parts, for example, on the gas tank cap.
Departure size;
Hub hole diameter size;
The size of the landing diameter;
Disc mount;
The shape of the holes for fasteners;
Information on disks (video)
Inches are the classic measure of wheel width. The value is marked as "J". For example, 5.5J. Stands for 5.5 inches wide. Tires are also marked in inches, each tire has its own rim.
Departure affects the functionality of the auto suspension in general, and bearings in particular. Incorrect departure will lead to premature wear of the chassis. Concepts such as positive overhang, negative overhang and zero overhang are used.
Departure calculation (video).
The hub hole is where the disc is screwed onto the hub of the car. Therefore, it must fit exactly. If the hole is small, the disk will not install. With a large hole, balancing with rings will be required.
Disc seat diameter. This is the disc diameter in inches. Marked with the letter R.
For example, R18 indicates an 18" disc.
We remind you that the required disc diameters for your car are indicated in the book for the operation of your car.
REMEMBER! The tire diameter must match the diameter of the rims.
location diameter.
Number of fixing holes.
In English - PCD (PITCH CIRCLE DIAMETER). In Russian - "razboltovka".
The number of mounting bolts can vary from four to six on average. Minimum 3. This is important and must be strictly observed.
The shape of the holes for fastening disks.
Forged disc bolts are slightly tapered. The length is shorter than others. In cast, the conical shape is more pronounced, here you need longer fasteners. Some designs use flat and hemispherical fasteners.
Humps.
Outside the disc there are protrusions that fix the tubeless rubber. They are called humps. They are present on every disc. With the exception of discs for pneumatic chambers.
Interesting fact.
For more than 100 years, pneumatic tires have been installed on cars, which are inflated with atmospheric air. Internal chamber pressure ensures structural rigidity and ease of movement. Until the 80s of the last century, a rubber or rubber chamber was located inside the tire. But, starting from the 2000s, tubeless tires came to replace chambered tires. Today, almost all cars, especially new ones, are equipped with tubeless tires.
In recent decades, stamped steel wheel rims have been widely replaced by cast models. Some car enthusiasts do this to improve the appearance of their cars, but for most of them, not only the aesthetic effect is important, but also improved performance.
So, what are alloy wheels and what are their advantages over stamped ones?
What are alloy wheels?
As it is easy to understand from the name, alloy wheels are products made by casting. Steel is not suitable for them for a number of reasons, therefore, aluminum alloys are mainly used for discs, sometimes more exotic alloys based on magnesium.
The finished disk is a solid casting, which, in order to acquire greater strength, is subjected to a hardening procedure that relieves residual metal stresses. After these technological operations, the surface of the disk is polished and covered with a special varnish to maintain a stable gloss.
The shape of the disc is the result of the painstaking calculation of the leading engineers of the largest automotive companies. The composition of the alloy and the technology of its preparation from the most famous manufacturers is often almost impossible to copy. That is why, despite their external similarity, discs produced under world brands are much more reliable and durable than their cheap Chinese copies.
Advantages of alloy wheels
When deciding to replace stamped steel wheels with alloy cast ones, each car owner must understand why he is doing this and what he will get as a result of the replacement.
So, what are the advantages of alloy wheels compared to stamped ones?
1. Light weight. Aluminum alloy wheels, in addition, in the absence of hubcaps, weigh much less than stamped predecessors - sometimes the weight reduction reaches 50% of the previous one. As a result, the load is reduced, and the car becomes more manageable, stable and obedient on the road. In addition, ride comfort is increased, as the suspension absorbs shocks and impacts more effectively. An important factor is the reduction of suspension wear, as a result of which the cost of maintaining it in good technical condition is reduced.
2. Openness of the brake system. Due to the absence of caps, the inside of the wheel remains open during the movement and cools naturally. This improves the performance of the brake system, provides it with greater reliability and reliability.
3. Corrosion resistance. Unlike steel, which rusts easily, aluminum alloys are resistant to corrosion even when the outer lacquer coating is covered with deep scratches.
4. Superior design. Wheel hubs form an elegant pattern, individual for each model. Well-chosen wheels can significantly improve the appearance of the car, give it individuality and enhance the dignity of the body design.
Disadvantages of alloy wheels
As happens everywhere, the disadvantages inherent in solid-cast wheels are an extension of their advantages. So, the strength obtained by hardening turns into brittleness: with a strong impact, the cast disk does not bend, but bursts. It is impossible to continue driving in this case, and if there is no spare tire in the trunk, the only way out is to call a tow truck. A broken disk can no longer be repaired - it only needs to be replaced with a new one.
A variety of disk designs can also turn into problems: if you need to replace one disk, it can be difficult to find an identical one in size and pattern. True, today the task is facilitated by Internet commerce, thanks to which disks of the desired shape can be found and ordered even on the opposite side of the planet.
The exposed spokes and rims that adorn the car in such a way need constant washing and cleaning, as road dust and dirt constantly penetrate into the recesses. If not cleaned properly, accumulated dirt can cause wheel imbalances, leading to uneven wear and premature failure of suspension components.
Properly and well-chosen wheels for a car are not only your safety and care for passengers, but also low fuel consumption along with an extended transmission life and a bewitching look of a stylish car.
Let's try to figure out how to choose the right alloy wheels and operate them correctly. The opinions of intelligent experts in this field and the recommendations of popular manufacturers of light alloy products will be taken into account.
Disk types
All rims can be divided into two groups - steel and light alloy (casting). The design of stamped wheels is simple and uncomplicated. vyshtampovyvayut and individual parts are interconnected by spot welding. Then the disk is painted and sent to the store or to the conveyor.
This way of equipping a car with disks is simple and inexpensive. A significant mass of cars coming off the assembly line have just such wheels. Casting installation is already an additional option for which you need to pay a decent amount.
Before choosing alloy wheels instead of steel ones, in favor of the latter, we can say that they have more, which means that after strong impacts they do not crumble or crack, but only deform. This feature allows you to restore the disc, even if the edges are heavily crumpled.
A significant drawback of stamped products, which is critical for many motorists, is the mass. Moreover, it cannot be reduced, because insufficient wall thickness significantly reduces the strength indicators of the entire wheel. In addition, steel models are susceptible to corrosion if the integrity of the protective coating is compromised. This also includes a monotonous and boring appearance, difficulties with and a negative impact on the dynamics of acceleration.
Alloy wheels
Before choosing alloy wheels, it is useful to know some of the benefits. Light-alloy models have extensive design possibilities along with high precision manufacturing. They are able to remove most of the heat from the main nodes, but the most important thing is the lightness of the design. It is possible to judge the specific merits of certain models if it is known how they are cast and with what alloy. So in this case the wheel is different from the wheel.
Ordinary models are made by casting or forging from stable alloys, where the basis is aluminum, titanium or magnesium. Magnesium and titanium models are much stronger and lighter than aluminum wheels. Before choosing magnesium-based alloy wheels, be aware that they are less resistant to corrosion, which means that you will have to constantly take care of a multi-layer protective coating. As for titanium, this is already an elite group, which is equipped with very expensive, sports and simply prestigious cars. For everyday driving on our roads, titanium models are simply a pity to use. Despite the strength of such products, they are prone to scratches.
Difficulties of choice
Before choosing alloy wheels for a car, remember that the purchase should be determined by your needs and, of course, the amount in your wallet. If your path is megacities and large cities, then magnesium or aluminum casting would be ideal. Do you have free funds? Please, titanium models are beautiful, ultra-reliable and will be a great addition to the elite surroundings.
If you value reliability, often drive out of town on bad roads and do not attend secular parties in your car, then it is better to stop at steel, stamped or forged products. In this case, they will not only be more practical, but will also save you the lion's share of the family budget.
How to choose the right alloy wheels for your car
In order to correctly select one or another model of a disk specifically for your car, it is necessary to clearly clarify some critical parameters. First of all, we find out the width and diameter of the disk. Then we specify the location of the mounting holes and their number. Next, pay attention to the diameter of the hub of your car and the departure rate. All main mounting dimensions can be found in the catalogs of tire and wheel manufacturers or you can measure everything yourself using a special tool. Before choosing alloy wheels for a car, and if you suddenly have any doubts, it’s better to go to a smart tire shop and figure everything out there, drawing all the dimensions and parameters that interest us on a piece of paper.
Disc diameter
This parameter is selected according to the recommendations of the manufacturer of your car. It must exactly match the landing diameter of the wheel. Recently, there are more and more extreme people who seek to increase the mounting diameter. For example, a 15-inch fit is rolled under 16, 17, or even 18-inch wheels.
All this is done for the installation, which, on the one hand, increases driving performance for the better, and on the other hand, increases the load on the main suspension units. And the comfort of driving on such tires is not the best. Before choosing alloy wheels of one diameter or another, you yourself must decide for yourself what is more important - sporty performance or driving comfort?
Rim width
If the manufacturer's recommendations for your rims for mounting diameter do not exceed 14 inches, then the width of the rim will fluctuate between 0.5-1.0 inches. For mounting diameters greater than 15 inches, the width will be slightly higher - 1.1-1.5" for the rim.
Which alloy wheel to choose is up to you, but a factory-width one is a better and more practical option. The use of wheels that are not standard for your vehicle is fraught with changes in the design profile of the tire, as a result of which the basic driving characteristics (pull resistance, steering response and lateral stiffness) may significantly deteriorate.
wheel offset
Reach is the distance between the mounting plane of the wheel and the longitudinal plane of the rim (symmetry). Wheel offset can only have three values: zero, positive, and negative. The indicator is indicated by a numeric or alphabetic value. For example, ET40 (mm) is a positive offset, and ET-40 is already negative, so do not get confused and take the minus sign for a dash or hyphen. The literal value is usually denoted by the words OFFSET and DEPORT.
Separately, it is worth noting that the larger the offset, the deeper the car sits in the wheel grooves. And the smaller this figure, the more the wheel sticks out of the niche. Most car owners tend to reduce this figure. In general, it is not entirely correct to deviate from the standard values \u200b\u200bthat were set on the factory conveyor, but sometimes, due to certain circumstances (frequent driving on bumpy or, conversely, perfectly flat roads), you can adjust the departure in the right direction for a more comfortable ride.
When it comes to buying wheels for a car, you often cannot do without the help of specialists. After all, the most common mistakes motorists make when choosing on their own, at first glance, are banal, but turn into either a loss of money or not for the better affect the safety of the driver and his passengers.
Firstly, the disc may simply not fit the hub of the car. For example, you picked up Opel wheels of suitable size for a VAZ or Zhiguli, and then, when installing the wheels, you found out that they only fit in appearance. In fact, the holes for landing the disc and the diameter of the hub are different for these cars.
It also happens that outwardly the dimensions seem to correspond, but the disk does not want to fall into place. What is the reason - specialists of a professional trade and service center, who have thematic literature at hand, will be able to explain. The site has a special service for selecting wheels for a car, which will show all available options. Without leaving your computer, you can get advice from the specialists of the online store.
Secondly, motorists often do not take into account that for alloy wheels, which are more voluminous in the mounting area, longer bolts are also needed. Including the so-called "secrets". The short ones that come with the car, like regular ones, “hooking” on several threads of the thread, can break off on the road. It probably makes no sense to describe the consequences of such a nuisance: a wheel that has fallen off, a car that has lost control.
The opposite oversight: the mounting bolts you bought were too long for the disc. In this case, during rotation, they touch the fixed parts of the car. For example, the handbrake cable spring in the rear drum of the Zhiguli. It is difficult to choose the bolts of the optimal length yourself. Again, this is the case when you need advice or direct assistance from a specialist.
Of course, you can buy original discs that the manufacturer recommends for a specific car. Often the "originals" are German-made. For BMW, Mercedes or Audi, the original disc will definitely come with a set of mounting bolts. It has only one drawback - the high price.
Do you want a combination of price and quality? You can consider the option of a "second set" of disks. These are high-quality discs that are produced by factories in the same: Germany, Taiwan or Italy. Mounting rings, bolts or nuts to them are supplied "shaft". It is not difficult for a specialist to figure out what fasteners are needed for a particular disk. He knows for sure that for wheels with the same hub diameter, say d75, which are equally suitable for Mercedes and Audi, the first car needs rings 66.6 and fixing nuts / bolts 12x1.5, the second car needs rings of size 57.1, nuts/bolts 14x1.5. However, some Mercedes models require 14x1.5 mounting nuts / bolts. It happens that market sellers or traders of small shops do not know about these subtleties. Therefore, it is better to make such purchases in specialized centers.
Every car enthusiast wants to make his car different from the rest, standing out against the background of the general flow. Stylish rims are one of the most affordable ways to give her a personality, and for those who want to see how the new rims will look on their car, we have a convenient service - trying on rims by car brand online. But first you need to find out what needs to be done in the event that the selected rims do not fit the car perfectly.
Magnesium or aluminum?
Probably, we will not make a discovery if we say that when putting alloy wheels on a car, car owners, first of all, think not about their advantages, but about how the car will look. Looking at brand new, glossy discs, one involuntarily thinks: “How long will they be like this?”
More resistant to water, salt, road chemicals and mechanical damage - aluminum alloy wheels. In addition to a special coating and varnish resistant to destruction, the surface of the aluminum alloy disc is protected by a durable oxide film, the thermal expansion coefficient of which is approximately the same as that of the metal itself. Aluminum utensils used in everyday life also have such a film - this is a unique property of this metal. How stable this film is is evidenced by the fact that at low temperatures aluminum does not dissolve even in nitric acid concentrate!
There is a similar oxide film on magnesium alloy discs, but it is far from being as dense. Due to its “friability”, it does not resist further oxidation of the metal. However, magnesium alloy rims are lighter than aluminum alloy rims. But, due to the reasons described above, they are more susceptible to the effects of salt and reagents on the roads.
Exploitation
So: the disks and the mounting bolts for them are available, everything “sat” perfectly on the car ... It seems that only recently the wheels were balanced, the weights are all in place, and there are already signs of imbalance: vibration in the wheels and “spotty” wear on the treads . Perhaps the reason is in the disk. In theory, for its self-cleaning, the action of inertial force should be enough, and infrequent trips to a cosmetic wash eliminate what the laws of physics could not cope with.
The rapid accumulation of dirt between the spokes of the disc, when it has to be picked out, means that in pursuit of fashion or in an effort to increase strength, the manufacturer has unsuccessfully designed the disc. It should also be remembered that from time to time wheel balancing correction is required. And it is better to choose self-adhesive balancing weights for wheels. At the attachment point, where the bracket of a standard weight is hammered, the varnish is damaged, and lead, interacting with the metal of the disk, accelerates the corrosion process at times.
In addition, standard brackets were originally designed for use on stamped steel wheels and hold the weights on an alloy wheel much worse.
Certification
There is an opinion that alloy wheels are inferior in strength to conventional steel stamping. The reality is that a cast disk can only crack upon impact, which will also disable the “stamping”. It is enough to know that Russian certification standards for light alloy wheels are much tougher than American, European or Japanese ones. During their development, the state of roads in our country was taken into account. At first, when importers were just developing our market, they often recalled products in order to finalize them in accordance with Russian requirements. Another thing is that when buying a disc, it will not be superfluous to ask the seller to show a quality certificate for the product.
Before proceeding to the description of production technologies, we note that the so-called "casting" has a large number of advantages. Moreover, they are put in opposition not only to iron stamping, but also to forged products, which are traditionally considered one of the most durable and strong.
Benefits Only
If we talk about the advantages of "casting" in relation to "forging", it should be noted that they have a more affordable cost. Among imported products, it can reach hundreds of percent. Of course, on the domestic market today you can find the products of Russian enterprises, in the past focused on meeting the needs of the defense complex. These forged wheels are relatively inexpensive. But even they cannot compete with "casting" on price.
In relation to stamped iron disks, cast "wheels" look even more preferable. Their advantages over steel stamping are as follows:
- Light weight. This is perhaps the main advantage of light alloy casting. As a result, the load on the chassis is significantly reduced, the dynamic performance of the car is improved, and fuel consumption is reduced. In addition, the passive safety of the car is significantly increased, due to the fact that contact with the roadway when hitting an obstacle is restored much faster. Thus, controllability is improved.
- Attractive design. To be completely accurate, the design may be different. The choice of a particular model is a matter of taste and personal preference. But the main thing is that it simply exists. Unfortunately, this cannot be said for iron stamping.
- Finally, it is impossible not to note the practicality of such a solution. Alloy wheels do not require any special care. They don't rust and don't need to be painted. To maintain the proper appearance, it is enough to periodically wash them and simply wipe them with a cloth.
A bit of negativity
Talking about the advantages of "casting", it would be unfair not to mention its shortcomings. And they are. This is, among other things, the fragility of the disk. The fact is that the alloy in the process of casting receives a free non-directional crystalline structure. This negatively affects its strength. Of course, we are not talking about problems in everyday use. But when hitting an obstacle at high speed, mechanical damage is not excluded, which, moreover, is difficult to repair. Although in modern conditions for the production of rims, this circumstance is gradually losing its relevance. Thanks to the use of low pressure casting technology, as well as casting parts with counter pressure, this minus is leveled. Therefore, when choosing, we recommend paying attention only to high-quality products manufactured under well-known trademarks and certified in Russia.
How are alloy wheels made?
Modern casting technologies involve the use of special molds for pouring metal alloys. The metal in the mold cools down, but the processing of the workpiece does not end there. After the part is placed in a chamber heated to several hundred degrees (usually the temperature is maintained within 500 degrees Celsius). Heat treatment alternates with rapid cooling of the part. This process is called hardening and allows you to achieve a homogeneous structure of the metal. In addition, in order to bring the physical properties of the metal closer to the structural balance, the stage of artificial aging is provided during the manufacture of the discs. It involves heating and holding the part for 5-6 hours at a phase transformation temperature (about 150-220 degrees), after which the disk is cooled under atmospheric conditions. The final links in the technological chain of production are machining and painting.
Aluminum in the production of alloy wheels
One of the most popular types of raw materials used for the manufacture of alloy wheels is aluminum, to which the necessary components are added (as a rule, silicon acts as an additive). The advantages of such a design solution are obvious:
- First, aluminum is a relatively inexpensive metal.
- Secondly, it is a material with a low specific gravity, since the density of aluminum is only 2.7 g/cm3.
- Finally, this type of metal is not subject to corrosion, which significantly increases the service life of finished products. This effect is achieved due to the ability to form a strong Al2O3 oxide film on the surface.
Finally, it should be noted that aluminum has an extremely low thermal conductivity. This makes it possible to achieve better cooling of the parts of the brake mechanism of the car. Combined with the high precision manufacturing of aluminum-silicon alloy wheel rims and other components, all of the above factors are the undeniable advantages of "casting" in this category.
As usual, not a single barrel of honey is complete without a fly in the ointment. Now about the disadvantages: this is, first of all, a low level of plasticity of the material. Thus, due to significant shock loads, aluminum rims do not bend, but crack. That is, they cannot be repaired.
A few words about the benefits of magnesium
Magnesium often acts as an alternative to aluminum in the production of alloy wheels. As a rule, alloys based on this metal also contain aluminum, but its proportion is insignificant. The main advantage of magnesium discs is their extremely low weight, because the density of the metal is only 1.7 g/cm3. In addition, this type of material is characterized by high specific strength. According to the above properties, magnesium unambiguously outperforms aluminum "casting". In all other respects, they are not inferior to them. But magnesium has one not very good property - alloys based on it are unstable to aggressive environments, they are subject to corrosion. To eliminate this problem, manufacturers prefer to use multi-layer coatings.
Instead of an afterword
Returning to the original formulation of the question "magnesium or aluminum", we can say that there is no unambiguous answer to it. It all depends on the specific operating conditions of the car. If you choose wheels for everyday driving, then it is advisable to give preference to more practical aluminum. If it is supposed to technical refinement of the car with a simultaneous improvement in dynamism and other characteristics, then you should pay attention to magnesium.
