Stamped or alloy wheels: what to prefer and what parameters to choose?

Any motorist sooner or later faces the problem of choosing and buying tires. At the same time, many people want to buy rims at the same time as tires. This is right. Because by assembling the wheels once in the future, you will save your money and time by not standing in huge queues at the tire fitting twice a year. It will be enough for you to balance the wheels (and this can be done in advance, without waiting for the "season" of changing tires) and change them in any car service or even on your own. In addition, by installing alloy wheels on a car, for example, you can significantly improve the external appearance of your car.

But here the question arises - how to choose the right wheels for your car?

Let's start with what kind of wheels you want: or stamped? Both of them have their pros and cons. The positive side of stamped discs is their simplicity and reliability - even if the disc is damaged (dents), its shape can be restored by rolling it on a special machine, and in the field even with a hammer. Also, in most cases, stamping is cheaper than its cast counterpart. Of the minuses, one can note the “banality” of the appearance, as a rule, more weight and the fact that such a disc is extremely inconvenient to wash from the inside, and in winter this is especially true. With alloy wheels, the opposite is true. Pros: a huge selection of designs and even colors, less weight (15-30%) and ease of maintenance. Cons: Alloy wheels are more expensive and, if damaged, cannot be repaired. A damaged wheel must be replaced with a new one, although many workshops now offer alloy wheel repairs. We do not recommend doing this due to the peculiarities of the alloy wheel production technology, but this is a topic for another article.

And now, let's say you have decided on the type of disk. But the next question arises: how to choose a disc that is right for your car? And what parameters do you need to know to make the right choice? Let's say right away that most car manufacturers do not give the full size of the disks in the operating instructions for the car, limiting themselves only to indicating the landing diameter and width of the disk, and in rare cases, indicating the offset of the disk. The missing parameters will have to be obtained from the specialists of the dealership or sellers.

Dimensions of stamped and cast wheels

The full labeling of the disk looks, for example, as follows:
6.5Jx16 H2 5/112 ET50 dia-57.1. Now let's decrypt:
6.5 - the width of the rim of the disk (measured in inches) - the width of the part on which the tire is put on;
J- the shape of the side rim. There are other designations, but a simple car enthusiast does not need to know this;
x- the rim is non-separable (the vast majority of passenger disks are now produced just like that);
16 - nominal bore diameter (measured in inches). This diameter must be strictly equal to the landing diameter of the tire. It is unacceptable, for example, to install a tire with a diameter of 16 on a 16.5-inch rim.
H2- Hump - a small annular protrusion that runs along the rim of the disk closer to its edges. It is necessary to securely fix the tubeless tire on the rim. The number 2 in this case indicates the presence of 2 humps, i.e. one near each of the rims;
5 - the number of holes for attaching the disk to the car;
112 - PCD (Pitch Circle Diameter) - the diameter of the circle passing through the centers of the mounting holes (measured in mm);
ET(also spelled OFFSET) - disc offset (measured in mm) - distance from the mating plane to an imaginary plane passing through the middle of the disc rim (in our case, 50 mm);
Dia(also spelling D, Centerbore is possible) - the central hole (measured in mm).

Now let's figure out which of the sizes can be changed and within what limits, and which should remain "untouched".

The width of the rim depends on the width of the tire mounted on it. For example, a 205/55R16 tire can be used on a 6" to 7.5" rim, with a recommended 6.5" width. Therefore, the size of the disc rim can be chosen within these limits. The table of correspondence of tires and disks will help correctly.

Landing diameter - there is even more choice. The minimum diameter is always indicated in the car's manual and can increase almost indefinitely. But keep in mind that the larger the disc diameter, the lower the tire profile will be, and this, in turn, negatively affects the ride comfort, but the car's handling at high speeds improves.

Number of mounting holes - this parameter remains unchanged.

PCD, in most cases, cannot be changed either. Although some manufacturers of alloy wheels (OZ Racing, AEZ, DOTZ) have special bolts with eccentrics that allow you to screw, for example, wheels with PCD 100mm on cars with PCD 98mm. On cars that are fastened with nuts, similar eccentric nuts are used. The maximum displacement of these bolts and nuts is 1.2mm, so the disc PCD difference cannot exceed 2.4mm.

Departure - a change in departure is possible in the direction of its decrease. But it is desirable that such a decrease be within the limits of up to 1 cm. In the direction of increasing the number of departures, as a rule, changes are not possible, because. the LESS the offset number, the MORE the disk "goes out" of the car relative to the wheel with the "native" offset, and vice versa. Thus, with an increase in the number of overhang, the disk will sink more into the car, while the likelihood that it will hit the suspension or brake parts increases significantly.

The central hole in the stamped wheel must necessarily be equal to the diameter of the car hub, for its proper centering on the hub. With alloy wheels, the situation is somewhat different. At present, most of the manufacturers of alloy wheels, both domestic and foreign, make wheels with a universal center hole. And for centering, a special centering ring is used, in which the outer diameter is equal to the diameter of the hole in the disk, and the inner diameter is equal to the diameter of the car hub. I'll give you an example. The disc size 6.5x16 5/114.3 et45 dia-72.6 can be installed on Mitsubishi vehicles with a hub diameter of 67.1mm and Toyota vehicles with a hub diameter of 60.1mm. So, in order not to make two different cast disks, the manufacturer produces one disk with a larger central hole, in our case 72.6mm, and two centering rings - the first 72.6 / 67.1 and the second 72.6 / 60.1. When putting the wheel on the car, the ring is inserted into the disc, after which the disc is installed on the car, centered on the hub, and tightened with bolts or nuts. After that, the centering ring does not carry any load and does not affect the driving characteristics of the car. Centering rings can be supplied with discs or supplied for a fee. I repeat, stamped discs cannot have such rings.

Alloy wheels. Underwater rocks.

The discs also have a very important parameter that is not indicated in the marking - the maximum load. Therefore, even if the disk fits your car in all sizes, it is better to specify the load. For domestic wheels, you can see it in the disk passport, for foreign ones - you have to search on their websites on the Internet.
And the last thing to keep in mind when buying discs, there is a so-called X factor- this is when all the dimensions of the disk coincide with the required ones, but the disk still does not stand on the car, it rests on suspension parts or brake mechanisms. This is due to the very form of stamping or casting spokes. Therefore, we always recommend that our customers, before beading a tire on a wheel, first try it on a car on the front and rear axles, screwing it on a couple of bolts and carefully turning it.

At present, the vast majority of disk manufacturers have catalogs of guaranteed disk applicability on their websites on the Internet. If there is your car in such a catalog and there is a disk you like for it, then you can safely buy it, which means it is completely suitable in all respects.
Now the choice has become much easier than it might seem at first glance. Good luck with your purchase))

Marking of car rims

Disc labeling seems very complicated. But this is until you get acquainted with the decoding of this abbreviation.

Let's take a look at the example of a standard UAZ disk for bridges of the "spicer" type: 6½JxR16 PSD 5x139.7 H2 ET40 c.o.108

Basic disk dimensions

6½ JxR16 PSD 5x139.7 H2 ET40 c.o.108
First digit 6½(Rim Width) - rim width in inches. Not the entire disk, but the rim, i.e. where the tire will be. It is size "B" in the picture. Often the width is indicated in decimal fractions. 6,5"" (one English inch, if converted to the metric system, is equal to 25.4 mm)
In this case, the width of the rim is 6.5*25.4=165.1 mm. Note that this parameter is directly related to the width of the tire. For each tire, there is a fork (from and to) of the permissible width of the disk on which this tire can be installed. The best option is for the rim width to be somewhere near the middle of the allowable range for this tire. You can find out the allowable rim width for a particular tire using tire calculator. It should be understood that if the width of the disk does not match the width of the tire, then this will create a problem with the beading of the tire on the disk, and will also noticeably worsen the performance of the tire, therefore it is necessary to pay attention to this parameter.

6½J xR16 PSD 5x139.7 H2 ET40 c.o.108
J(Rim Flange) - this letter encodes technical information about the flanges of the disc rim (design, shape, height). There can also be letters (JJ, JK, K, B, P, D ...). The most common rim types today are J (mostly for 2WD vehicles), and JJ (usually for 4WD). Rim flange disc but affect the installation of rubber, compensating weights, as well as the resistance to displacement of the tire on the rim in extreme conditions. Differences between the types of rims denoted by different letters may be insignificant, but they cannot be neglected.
The contact area of ​​the tire to the rim is very critical, small changes in the bead profile of the tire lead to the complexity and even the impossibility of installation, as well as the inability to maintain the required pressure inside the wheel.
Rim contour designations A and D fall under the Cycles, Motorcycles, and Scooters category, and are also possible under the Industrial Vehicles and Lift Trucks category. Naturally, the contours have completely different geometries for the same designation in two different categories.
Beads marked S, T, V, and W are categorized under Commercial Vehicles, Flat Base Rims, while rims E, F G H are categorized under Trucks, Stripped Rims ( Commercial Vehicles, Semi-Drop Center Rims). Obviously, despite external interchangeability, it is still better to choose the parameter recommended by the car manufacturer.

6½Jx R16 PSD 5x139.7 H2 ET40 c.o.108
“x” means that the rim is one-piece, i.e. consists of one element, and the “-“ sign means detachable, consists of several elements. The one-piece disc rim is more rigid and lighter than the split one, it consists of one element. It is possible to mount tires with elastic sides on such disks, therefore it is used for wheels of cars and small trucks. The split rim consists of several elements and is used in the construction of the wheels of buses and trucks. The tire beads of such vehicles are so rigid that mounting through the rim flange is not possible.

6½JxR16 PSD 5x139.7 H2 ET40 c.o.108
R16(rim diameter) - the diameter of the wheel rim (in the figure it is the dimension "A"), measured in inches. This value is determined without taking into account the height of the rim flanges.

6½JxR16 PSD 5x139.7 H2 ET40 c.o.108
PSD- an abbreviation denoting that the disk mounting parameters are standardized. This parameter is often omitted, or written instead (PCD)

6½JxR16 PSD 5x139.7 H2 ET40 c.o.108
5x139.7- directly the parameters of fastening the disk to the hub.
First number 5 indicates the number of mounting holes on the disc. Often, especially on alloy wheels, number of holes marked separately by letters LZ
Second number 139,7 is the diameter of the circle in millimeters PCD(Pitch Circle Diameter), on which these holes are located (or rather their centers).

When replacing disks with analogues, it is very important not to make a mistake, since there are many different standards for this parameter, and the difference between adjacent ones is sometimes only a few millimeters. Therefore, for example, a disc from a car with PCD = 120.65 visually fits perfectly on a hub with PCD = 120, but this does not mean that it can be used on this car.

A is the width between the centers of two adjacent holes, mm.
B is the diameter of the conditional circle along which the centers of the mounting holes (PCD) are located, mm

The main thing to understand here is that despite the noticeable difference in the diameter of the mounting holes of the disk and bolts (studs), the car manufacturer very accurately calculates the fit of the wheel on the hub. This is due to the fact that any slightest deviation of the center of the hub from the center of the disk will not only cause the wheel to beat (usually accompanied by vibration on the steering wheel), but also jeopardize the reliability of the wheel fastening, because if the diameter of the mounting holes does not match the parameters of the hub, then fully tighten all mounting bolts (nuts) with a conical base (which should ensure the centering of the disc on the hub) is not possible. And this is a threat to life.

As for the fasteners, you need to know a few more subtleties: when replacing a stamped steel disk with an alloy one, you will have to use bolts (or studs) that are longer than standard ones. This is due to the fact that an alloy wheel is thicker than steel.

It is necessary to select so that the length of the thread that is screwed into the hub (or into the nut) when attaching the wheel is at least 6-7 full turns.

If the disk is fastened with nuts (as on UAZ), then most likely, when replacing with an alloy wheel, in addition to the studs, you will need elongated nuts

And on the Patriots, the wheel nuts and spare wheel nuts are different


Left: UAZ-Patriot wheel nut (M14x1.5); Right: spare wheel nut (M12x1.75)

In addition, the old fasteners will not work if holes are provided on the new disk, for example, for tightening on a sphere, and the bolts you have (regular) are tightened on a cone.

A - bolt and nut without head. The faces of the hexagon go to the cone; B, C - bolt and nut with head.

6½JxR16 PSD 5x139.7 H2 ET40 c.o.108
H2 options: (H, H2, FH, AH, CH…) – these letters encode information about the design features of the disk rim shelves and protrusions (humps) on them.

Humpami(from the English hump, "elevation, hillock") are called annular protrusions along the edges of the rim, designed for tubeless tires. The main purpose of the humps is to securely fix the tire bead in turns in order to prevent depressurization of the wheel. In the designations of disks that have one hump along the outer side, there is one letter H.
But many disc models are equipped with a hump along the inner edge of the disc, as indicated by the H2 index. Two humps increase the reliability of fixing the tire on the wheel, but create problems during its installation.
Therefore, on some discs, the second hump is made as if truncated in height. Such humps are called flat (flat hump), in the wheel marking they are indicated by the letter X .;

The following designations are also possible: FH - (Flat Hump) a flat-shaped hump, AH - (Asymmetric Hump) has an asymmetric shape, CH - (Combi Hump) a combined shape. The complete absence of humps is possible, while a special shelf SL (Special Ledge) is made on the disk, the design of which is designed in such a way that the tire only holds on to the edges of the rim and does not come off when driving.

6½JxR16 PSD 5x139.7 H2 ET40 c.o.108
ET40(Einpress Tief, German); - disk overhang(mm). The distance between the plane of application of the disk to the hub and the central axis of the disk. This parameter must meet the requirements of the automaker, since the key parameters of the suspension and steering mechanism of the car are calculated for it. The offset of the disc does not depend on the diameter of the disc, nor on the width of the tire, nor on any of its other parameters. For one hub, the offset is the same for all sizes of tires and rims. Designation options (depending on the country of production): OFFSET, DEPORT.
We often talk about positive overhang and negative overhang. Everything is simple here: if the landing plane is offset to the inner side of the disk - overhang negative. If to the outside - then positive. A positive disc overhang is indicated simply by a number: ET40, and a negative offset by a negative number: ET-40.
A variant is possible when the mating plane is in the center of disk symmetry. Then the overhang is zero and is designated as ET0.
It is allowed to use disks with a spread of + - 5 mm from the standard for this car model.
(It is precisely because of the difference in offset that wheels from UAZ-Patriot with Spicer bridges with ET40 do not fit UAZ-Hunter with Timken bridges, where the offset is ET22)

6½JxR16 PSD 5x139.7 H2 ET40 c.o.108
c.o.108; d108 (DIA) – Centering hole diameter on disc. Must exactly match the diameter of the seat cylinder on the hub. You need to understand that in addition to the centering function, the landing cylinder has another, no less important - it partially takes on the load that falls on the mounting bolts (studs). Therefore, if the centering hole of the disk you like is larger than the landing cylinder of the hub, you will have to use special adapter rings, which can be bought at tire centers, or ordered from Kulibins. But at the same time, the outer and inner dimensions of the centering ring must exactly (!) Correspond, respectively, to the diameters of the hub cylinder and the centering hole of the disk. There can be no gaps of 1 or a couple of millimeters here - otherwise the meaning of installing these rings will be lost.

A few more words about spacers (adapter rings) for disks.
It must be said right away that their application highly undesirable since this design greatly reduces the reliability of wheel fastening and it is not uncommon for a wheel installed on such a delivery to come off with it. But if you still decide to use them, then it is better to refuse to buy supplies with through bolts.

Option 1. The thickness of the spacers is 3-6 mm. These spacers are made without a hub for the rim, since their small thickness allows the rim to be centered on the standard hub of the car.

Option 2. The thickness of the spacers is 12-25 mm. The design of these spacers includes the presence of a hub for centering the rim, which eliminates imbalance when the vehicle is moving.

Option 3. The thickness of spacers is 25-50 mm. A feature of this option is the presence of pressed-in wheel studs in the design of the spacer. During installation, the spacer is first attached to the standard studs with special nuts included in the kit, and then the rim is attached to the spacer using standard wheel nuts. Ideal for 4x4 SUVs.

Option 4. The thickness of spacers is 25-50 mm. Spacers of this type are equipped with special bolts, with which they are attached to the hub of the car, after which the rim is attached to the spacer using its standard bolts.

X-factor - (X-factor, Caliper Clearance, Brake Clearance): This is the distance between the mating surface and the back side of the disc. The concept is rather arbitrary. The design of the rim is regulated by the standards, since it is necessary to ensure a fit on the rim of the pneumatic tire, while the design of the disk is quite free. At the same time, it must provide compatibility with the brake elements, the necessary strength of the wheel and an attractive appearance. Simply put, if the x-factor is large, then the wheel will "get up" on the car, where the caliper strongly protrudes beyond the mating plane. If the x-factor is close to zero, then the wheel is designed for cars where the brake elements do not protrude beyond the mating plane, for example, like a UAZ with drum brakes. In many jeeps, including the Niva 2121, the design of disc brakes is such that the caliper practically does not go beyond the mating plane, and, accordingly, the wheels for these cars can be with a small x-factor. We emphasize once again that the x-factor is a slang concept rather than an engineering one. Even on a wheel with a large x-factor, the disc may touch the caliper at the disc-to-rim transition or the disc-to-hub transition.

So,
The disk MUST also include:

• trademark or manufacturer's name
• date of manufacture. Usually a year and a week. For example, 0512 means that the disc was released on the 5th week of 2012
• size wheel rim, rim offset
• authority mark: SAE(Society of Automotive Engineers), VIA(Independent Japan Automobile Inspection Association), ISO, JWL(Japanese National Mandatory Standard for Alloy Wheels), TUV(Automotive German Association of Technical Supervision). This, speaking in Russian, OTK. Many firms brand their products not with dry alphanumeric indices, but with graphic pictograms.
  On alloy wheels, in addition to the OTK brand, they also put x-ray control stamp, which indicates that the disk has no internal defects - casting shells
to disk ( MAX LOAD) in kilograms or pounds. For example, the maximum load MAX LOAD 2000LB 2000 pounds (908kg)

Alloy wheels are marked in accordance with GOST R 50511-93, which specifies the mandatory parameters that must be present on the disk.

The disc MAY HAVE:

• PCD 139.7/5– connecting dimensions;
• MAX PSI 50 GOLD- means that the tire pressure should not exceed 50 pounds per square inch (3.5 kgf / sq. cm), the word COLD(cold) reminds you to measure the pressure in a cold tire. (MAX PSI indicated only by Americans)
• mode of production, for example, if the disk is forged, - FORGED ("Forged"); this inscription is not provided for by any standards, it is knocked out on the disk exclusively for the public, since forged disks are considered very prestigious.
• beadlock(Bedlock) - a disk with a beadlock - a device for fixing a tire on a disk. The use of such discs on public roads is unacceptable.
• Beadlock Simulator- Imitation of a bedlock. The design of the disk imitates the presence of a beadlock on it. This is a decorative element, and in terms of performance, such discs should not differ from ordinary discs of the same series.
• CONE 15– diameter and shape of mounting holes
• KR- diameter of the decorative cover.

Since the roads in our country are very different from European ones, it is better to buy disks that have passed Russian certification. Imported discs, if not imported from third world countries, are outwardly good, but many of them are designed for normal roads and therefore do not meet Russian requirements for


Where:
1 - Abbreviated name of the manufacturer (Kremenchug Wheel Plant)
2 - Country of origin (Ukraine)
3 – Production date (March 2011)
4 - Size (16" one-piece disc 6.5" wide, with J-type disc rim and two H-type humps)
5 - Disc offset (positive offset by 40mm)
6 - Maximum static load (825 kgf) 225/75 R16 steel disc, for spicer bridges: 6.50JxR16 PSD 5x139.7 ET 40 c.o.108 alloy wheel, for spicer axles: 7.00JxR16 PSD 5x139.7 ET 35 c.o.108 steel disc, for Timken bridges: UAZ 3151*
UAZ 3741* standard tire sizes: 215/90R15; for 16"" drives: 225/75R16
respectively, the dimensions of the chambers for tube tires: 8,40-15 or 225-16 standard disc, for Timken bridges: 6.00LxR15 PSD 5x139.7 ET 22 c.o.108
You can install 16"": 6.00JxR16 PSD 5x139.7 ET 22 c.o.108

If you don't find data for your car, you can measure it yourself. To choose the right disk, you need to know six basic parameters of the disk:

But in order to measure not all parameters, some of them can be read in the instruction manual for your car or on the spare wheel if the car is equipped with a cast (aluminum alloy) full-size spare wheel (the same as all other wheels that are on the car ).

To do this, you need to remove the wheel from the trunk and read the inscriptions on the inside of the disc.

If your car is equipped with a “roll-out”, then you need to remove one wheel from the car if there are “alloy” wheels.

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The first and second columns contain standard sizes of tires and disks. In the remaining columns, the dimensions desired for installation. The calculator will help determine tolerances and selection alternatives.

The tire calculator allows you to compare the dimensions of tires of different sizes. For example, choose wider tires, but keep the outer diameter of the wheel the same or find out how much the car's ground clearance will change if you put tires of a different profile.

To select an alternative size in one half of the calculator, you need to specify the standard or existing tire size, in the next half - the desired or alternative.

The calculator displays the recommended rim width for a particular tire size, as well as the outer diameter and wheel width. The most important parameter is the outer diameter of the wheel. You should pay the most attention to its change.

The second important parameter is the actual height of the tire profile. It is usually expressed as a percentage of the width: for example, 205/55 R16, where 55 is 55% of the tire's width. That is, 205*55/100=112.75 mm is the actual profile height of this tire.

Tires with different widths, standardly installed on a car, have different profile heights in percent, but the same in millimeters. For example, tires with dimensions 275/40 R20 and 315/35 R20 have a profile height of 110 and 110.25 mm, respectively.

Some features of the selection of tires:

• The wider the tires, the better handling, but less hydroplaning resistance and more rutting, and reduced comfort - low profile tires are stiffer.
• Lower profile - heavier wheel. This is due to the fact that the disk is heavier than rubber, the mass of the wheel increases and this worsens the performance of the suspension. In addition, the mass of metal is distributed closer to the outer edge of the wheel and increases the moment of inertia (for cars with a powerful engine, this is not essential).
• With an increase in the profile, the car becomes more rolly, it reacts worse to control, but it goes through bumps more easily, the tires are less sensitive to the sharp edges of the pits, and comfort becomes better.
• A significant change in the outer diameter of the wheel leads to a distortion of the readings of the car's instruments, in particular, mileage and speed.

Our tire calculator - professional calculations in no time!

The correct choice of rims depends on the technical characteristics that indicate all parameters, namely the width, diameter, offset, as well as DIA (hub bore diameter) and PCD (drilling parameters).

You also need to know the marking designation. It indicates the standard parameters of any type of wheel products:

• stamping;
• alloy wheels;
• forged.

Markings are indicated on the inside. Usually, manufacturers duplicate them in the accompanying documents and on the packaging if the product is new.

Disk options

To determine what the marking means, you need to know the width and diameter of the wheel product.

Drilling, or bolt pattern

This is one of the more difficult parameters to study, indicating the diameter of the mounting bolts. Drilling is measured from the center zone of the stud to the opposite zone of the element on the wheel.

Quite often, manufacturers indicate the parameters of the disc bolt pattern through a fraction, depending on the number of holes for fixing.

Suppose the indicators are 6/222.25. The first number indicates the number of holes for fastening bolts, and the second number indicates the number of holes drilled in millimeters.

Disk distance

This indicator is marked with the English letters ET. What is ET in discs and why is it? The indicator indicates the distance from the plane of the wheel product to the middle zone of the rim. The mating surface of the wheel product indicates the pressing plane of the disk to the hub.

Departure options can be:

• with a zero indicator;
• with negative;
• with positive.

Zero offset indicates that the plane of the disk corresponds to its middle zone. Thus, the lower the indicator, the more the wheel product protrudes from the outside of the vehicle. If the overhang is increased, this means that the disc is recessed into the interior of the vehicle.

It is also necessary to take into account the fact that, depending on the width of the product, the departure indicators differ. Manufacturers indicate in the accompanying documentation for the vehicle a lower offset value for wheels with a large width.

What is HUMP (H)?

The hump is a protrusion of the ring on the disc rim. This element is used as protection against dismounting of a car tire. Usually 2 humps (H2) are used for the wheel.

In some cases, the hump may not be used, or only one is used, depending on the configuration of the car. Varieties of Humps:

1. combined (CH);
2. flat (FH);
3. asymmetric (AH).

PCD disk options

The PCD value indicates the diameter of the circle of the center holes on the rim. That is, this is the diameter of the holes for fastening the bolts.

DIA disk option

The DIA parameter indicates the diameter of the hole located in the center of the disk. Casting manufacturers prefer to create a large diameter center hole DIA. This is done so that the discs are applicable and universal for any type of car.

Despite the fact that the size of the hub may differ depending on the model of the vehicle, the auto disk is installed using an adapter ring, bushing.

Marking

As an example, consider the wheel rim marking 9J x20H PCD 5×130 ET60 DIA 71.60:

1. The number 9 indicates the width measured in inches. To convert inches to centimes, the total is multiplied by 25.4.
2. The letter J indicates structural elements: the shape of the disk flanges. This parameter does not play an important role in the selection.
3. The letter X stands for inseparable disk.
4. The number 20 indicates the diameter of the fit of the wheel product. This indicator corresponds to the fit of a car tire.
5. The letter H denotes the presence of one hump or protrusion on the rim.
6. Abbreviation PCD 5×130, where the number 5 indicates the number of holes for fastening nuts or bolts and the number 130 indicates their PCD diameter in millimeters.
7. The ET60 marking indicates disc offset. In this situation, the indicator is 60 mm.
8. The DIA value of 71.60 indicates the diameter of the center drill. Usually, DIA corresponds to the fit of the hub and is indicated in millimeters. If the DIA is larger than the hub diameter, then a center fit ring is used to install the disc.

Information is also attached to the label:

ISO, SAE, TUV - these abbreviations indicate the organizations that performed the inspection of the wheel product, similar to the Russian GOST. Standards that correspond to the wheel marking are also indicated.

Maxload indicates the allowable load on a car wheel. This indicator is indicated in kilograms and pounds.

What does parameter 700c mean?

This designation is used for large types of wheels for SUVs and Niva. According to the accepted ISO classification, this figure is 29 inches. Typically 700c wheels are used for off-road racing.

By using 29 inch wheels:

• improved management performance;
• the braking distance on unpaved surfaces is reduced and aerodynamics are increased;
• the car's patency on soft soils and sands increases;
• it becomes possible to install powerful brakes.

In order to select the wheels corresponding to a particular type of car, it is recommended to determine the diameter of the wheel and analyze the markings indicated on the rim. Also, do not forget that this element ultimately depends on safe driving.