What do the numbers on a bicycle tire mean?

French marking

In France, the marking may look like this: 700 x 35C. There it is customary to mark the product by the outer diameter, width and inner diameter, where 700 is an approximate indicator of the outer diameter, and the letter is the inner diameter. The lower the indicator, the closer the letter is to the beginning of the alphabet.

Accordingly, A is the smallest and D is the largest. In the marking of the presented sample, the letter “C” denotes an outer diameter of 622 mm. Unlike other markings, the French record system is not used on all bicycles. For example, this designation is never applied to mountain bikes.

numbers, bicycle, tire, mean

Before and now

It is not so difficult to comprehend the wisdom of modern bicycle markers, but half a century ago, different countries of the world could not agree among themselves and bring the height and width of bicycle cameras to the same denominator. Sometimes tires were marked in the same way, which fit on the same rims. For example, the 26 rim size had to correspond to a 25 mm wide chamber, which in fact had a wheel with an outer diameter of 24 7/8. Some manufacturers deliberately indicated too approximate sizes in order to increase the number of forced sales, bypass competitors. Today, the question of decoding numeric encodings is available to the absolute majority of cyclists.

European mark

Most modern bicycles have tires on wheels that have a European marking using the ETRTO classification. This abbreviation stands for European Tire and Rim Technical Organization.In this classification, as a rule, the following types of markings are used:

  • double digital marking of bicycle tires (37-662), where the first number corresponds to the width of the bicycle tire in millimeters, and the second to its diameter.
  • triple digital marking of bicycle tires (28 x 15.8 x 13.8), which indicates the approximate outer diameter, height and width of the tire, respectively.

Interestingly, on Soviet-made bicycles, the double marking indicators are “rearranged”: first, the inner diameter of the tire is indicated (it is also the landing size of the rims), then the width of the chamber follows.

Currently, the marking, which has become widespread in Europe, is recognized as the most clear and convenient for use among all existing ones. Despite this, it is customary in France and the UK to label bicycle tires in their own way.

Inch marking

This marking, like the previous one, consists of two values ​​written through the multiplication sign or fraction. If the tires are marked, for example, as 28 x 1.4, the first number will correspond to the outer diameter of the tire, and the second to its intended width in inches.

Understanding Tire Sizes | Tech Tuesday #145

This type of marking has a significant drawback: it has approximate indicators, which makes it difficult to select bicycle tires with the same marker for different types of bicycles.

What is the landing diameter to tell the seller?

Summing up and returning to strict numbers, we must decide what marking to call the tire seller in your particular case.

To do this, you first need to determine the landing diameter.

  • Wheel rims with diameters of 28 and 29 correspond to 622 mm. (Tires of these two diameters differ from each other only in height).
  • For 27.5-inch wheels, the rim diameter can be either 584 or 590 mm.
  • 26 inches corresponds to 559 mm.

Chamber sizes

The dimensions of bicycle tubes directly depend on the size of the wheels, and they, in turn, depend on the type of bicycle. Before choosing one or another indicator for a benchmark, you need to remember that:

  • wheels with a diameter of 16, 18 and 20 mm and above are installed on children’s bicycles and BMX;
  • wheels with rim diameters of 22 mm and 24 mm are equipped with teenage bikes;
  • wheel diameter of 26 mm is considered ideal for mountain and city touring bikes;
  • 29-inch wheels are typically only found on 29ers and road bikes.

How bicycle tire markings stand

When buying a bicycle, one should not forget about such an important requirement for vehicles as the reliability of its component parts. In order to correctly carry out the selection and replacement of bicycle tires, it is important that the decoding of the marking of bicycle tires is not a secret for the owner of the bicycle.

And the width of the tires?

When choosing the width of the cameras, you can use the correspondence tables available on specialized technical sites or consultations of a trusted seller. It is important to remember that it is preferable to choose a tire with a width that exceeds the inner width of the rim by 1.5-2 times.

Otherwise, some difficulties may arise:

  • Tires that are many times wider than the rims make it difficult to control the bike at low speeds; may fall off the rim when suddenly turning; wear out quickly.
  • Tires with a width that is significantly inferior to the inner width of the rims increase the risk of punctures and mechanical damage to the rim.

In fact, everyone can choose the right size and decipher the marking of bicycle tires. So keep in mind 2 or 3 dimensions specific to your bike to name them as soon as the camera needs to be replaced. Well, if you don’t hope for memory, save the bicycle tire “for a sample” and go straight with it to buy a new one.

Tire markings. what the letters, numbers and color marks on tires mean

On the tires, in addition to information about the manufacturer, you can find many interesting markings regarding the size, carrying capacity, tire design and other parameters that are quite important when choosing automobile rubber. Consider the most common tire markings.

READ  How To Correctly Seal A Bicycle Camera

Standard tire markings

Tires are marked as 185/60 ZR14 82 H XL.

In this case, the number 185 will mean the width of the tire profile in millimeters.

The number 60 in the world is considered the height of the tire profile. However, this is not quite true. In fact, this is the ratio of the tire’s section height to its width in%. Tires with a ratio of 65 to 75% are most suitable for our roads. The lower this number, the lower the profile of the tire, and the more difficult its operation in the conditions of imperfect domestic roads.

The width and height of the tire cross-section are of great importance for the vehicle’s driving performance. Fitting a tire with a greater height and width will make the car softer, less likely to damage the disc, and less stress on bearings and suspension. By choosing wide tires for your car, you will get: good contact of the car with the road surface, good cornering at high speeds, improved acceleration and braking characteristics. But the disadvantage in this case is the high price, increased fuel consumption, as well as a slight increase in weight, especially in cars with a low-power engine (up to 1-1.5 liters). In general, wide tires are suitable for a fast and powerful car, and not for urban small cars.

“Z” indicates that this tire is specially designed for high speed travel (over 240 km / h). Normal low-speed tires do not have the letter “Z”.

Next comes the designation “R”. this is a radial tire, as opposed to a bias tire. Bias tires, by the way, are practically not produced anymore.

14 is the inner diameter of the tire, in inches, where the tire meets the rim (rim diameter). In this case, the rim of the tire is 14 inches and the rim for it must be of the same diameter. See Tire and Wheel Size Correspondence Chart.

The number 82 is the Tire Load Capacity (Maximum Allowable Wheel Load) index determined according to the Industry Standard Maximum Load Capacity chart. A tire with an index of 82 will safely carry 1,047 lbs (475 kg). The four tires together can carry a fully loaded vehicle with a maximum total weight of 4188 pounds. (1900 kg). In most cars, the driver’s side door jamb has information about the carrying capacity of a particular vehicle, as well as the tire sizes that are suitable for the vehicle.

The letter H is the speed index, which can be denoted by the following letters: L (up to 120 km / h), M (up to 130 km / h), N (up to 140 km / h), Q (up to 160 km / h), S (up to 180 km / h), T (up to 190 km / h), U (up to 200 km / h), H (up to 210 km / h), V (up to 240 km / h), W (up to 270 km / h), Y (up to 300 km / h). Speed ​​category letters indicate the maximum safe speed that the tire can carry under ideal conditions for extended driving.

“XL” or “Extra Load”. reinforced tires among tires of their standard size.

Additional tire marking

The umbrella sign, as well as the marks “Rain”, “Water”, “Aqua”, “Aquatred”, “Aquacontact”, mean special rain tires for confident driving on wet roads.

Winter tires, as a rule, have special markings, most often it is a sign “snowflake”, the inscription “Frost”.

All-season tires are designated by the abbreviations “MS” (MudSnow. mud-snow), “All Season”, “AS”, “AW” (Any Weather. any weather).

Temperature (A, B or C). heat resistance at high speeds (A is the best, C is the worst).

Traction (A, B or C). the quality of braking on a wet road (A. the best, C. the worst).

TL marking, “Tubless” stands for tubeless tires.

Bike Tires 101 : The basics of bike tire sizing

TT, “Tube type” (“Mit Schlauch”. on German tires) is the marking of tube tires.

“RSC” (RunFlat System Component). tires on which, even in case of damage and lack of pressure, you can drive from 50 to 150 km without exceeding the speed of 80 km / h. Run-flat tires are designated differently by different manufacturers:

  • Run Flat. from NoKian
  • RFT. from Bridgestone;
  • RunOnFlat by Goodyear
  • ZP from Michelin;
  • SSR. at Continental.

“Steel” refers to tires with steel cord.

“PR” is the strength of the frame. For cars, this figure is 4PR OR 6PR, for light trucks and vans. 6PR or 8PR.

“Reinforced” or “RF”. 6-layer reinforced tire.
“C”. 8-layer reinforced tire for trucks.

“Max Pressure”. the maximum allowable air pressure in the tire (kPa).

“Max Load”. the maximum permissible load on the tire (kg).

The “Rotation” mark and arrow on the sidewall of the tire indicate the recommended direction of rotation of the wheel for treads with symmetrical directional patterns.

The “Outside” mark shows the outside of the tire with an asymmetric tread pattern, and the “Inside” mark shows the inside.

The date of manufacture of the tire is four digits enclosed by an oval. The first two digits represent the week, the second two digits represent the year the tire was manufactured. For example, if the date is shown as “0512” it means February 2012.

As for domestic tires, only two indicators are usually affixed to them: the date of production and the series of production.

American tire markings in millimeters and inches. Converting US tire sizes to European

American tires are sometimes labeled as European. type 185/60 ZR14. However, the numbers are preceded by a letter, for example P 185/60 ZR14. over, the letter P stands for tires for a passenger car. LT (Light Truck) refers to tires for SUVs, pickups and small trucks. T. spare or temporary tires. Note that these symbols are placed only on American-made tires.

American tires manufactured for the US domestic market are marked in inches. The American marking in this case looks like 32×12.5 R17, where 32 is the tire profile width in inches, and 12.5 is the profile height in inches. That corresponds to the tires of the “European” standard size. 320/65 R17.

Colored markings on tires

Colored marks are provided by the tire manufacturer and carry important information. Most often four colors are used for tire marking. red, yellow, white and blue.

Most often, you can see the white mark in the form of symbols enclosed in a small circle. A white marker is placed by a person who checks the compliance of the released product with standards. In a way, this mark is equivalent to the OTK badge.

The red marker carries a double meaning. Typically, tires marked this way are used for the factory fit of the vehicle, and a small red circle indicates the heaviest area of ​​the tire body.

A faint yellow marker indicates the lighter part of the tire. This section of the tire should correspond to the position of the spool on the tube. This label is useful for the tire shop technician, as it facilitates the process of wheel balancing.

READ  What is the fluid in hydraulic bicycle brakes

Colored labels used by automotive rubber manufacturers are most often installed exclusively for car service specialists. The common man does not need to know their designation.

Often, colored stripes are applied to the tire tread along its entire length. They are necessary for warehouse workers to group tires of the same size and manufacturer. In addition, colored stripes indicate to the consumer that the tire has not yet been used. When driving a car, these stripes are simply erased on the road surface.

Explanation of the American size designation

American tire manufacturers resort to different tire labeling. The first one is very similar to the European one, only before the dimension there are additional letters P. passenger, LT. light truck or T. truck. For example, 185 r14c P means that this is a wheel with a tread width of 185 mm, a diameter of 14 inches and is intended for passenger cars.

The second system for classifying its products has a completely different look. If the European system measures the dimensions of car tires in millimeters, then the American one. in inches. However, it is quite simple to understand it. For example, there are numbers on tires 2711r15. The first number is the outer diameter of the tire, the second is the width of the tread, and the last value is the inner diameter.

Load indices

Immediately after the speed index on the tires of the car, there is an index of the permissible load on each wheel. For example, tire markings contain 88t. This indicates that the car can travel at a maximum speed of 190 km / h, and the maximum permissible load on each wheel is 560 kg.

On certain tires, you can find designations in the form of the letters XL or the word Reinforced. This marking is usually awarded to tires, the load index of which is higher than standard values. If the number 88 is written on the sidewall of the xl or extra load tire, then 3 should be added to the value. to decipher this figure is 91 or 615 kg per wheel.

Numeric designation of load in kg one wheel for passenger cars
60-70 250-335
71-80 345-450
81-90 462-600
91-100 615-800
101-110 825-1060
111-120 1090-1400
121-129 1450-1850

Yellow tire markings

Sometimes on tires you can find a yellow dot or triangle, which means the lightest spot on the tire. When mounting, align the mark with the heaviest part of the disc to facilitate balancing.

Additional inscriptions on the sidewall of the tire

On many passenger tires, in addition to the designation of the model and type of tread, there are additional markings:

  • the letter R indicates that the rubber is of a radial design. older models are designated by different letters;
  • the presence of the word steel in the structure means the presence of a steel cord;
  • An E in a circle indicates compliance with the European ece requirements;
  • Aqua. tires with improved performance on wet asphalt and in aquatred aquacontact rain conditions;
  • TL (TubeLess). tubeless tire, in the absence of this marking, the presence of a tube is required;
  • Outside. the outside of the unit. Differs from inner sides with asymmetrical tread. It will help you figure out which side should be outside when installing a set of rubber on a car;
  • DOT. compliance with the security requirements of the countries of standardization;
  • Rotation. applied to kits with directional patterns. The wheels must turn in the direction of the arrow;
  • Treadwear is an indicator of wear resistance. On many tires, the wear markings are made in the form of grooves. The increased number of layers is indicated by the letter C;
  • RF (RunFlat). rubber with reinforced cord. Able to travel more than 80 km at the lowest pressure. 0 atmospheres. There are cases when both punctured wheels kept the road well at speeds up to 80 km / h.

Explanation of tire sizes and parameters

A lot depends on the correct choice of footwear for a car. When deciding to buy a kit, you can be guided by various comparative tests. However, it is worth remembering that their characteristics must correspond to the operating conditions. In this case, the information indicated in the marking on the sidewall of the tire will help. Such inscriptions on the tire indicate the size of the product and its technological characteristics. Below we will decipher the symbols and try to figure out what the numbers and letters mean in the rubber marking.

Manufacturing date

Next to the place of the standard size of the wheels, there are four more digits indicating the date of manufacture of the kit. It is quite easy to read if you are familiar with the calendar. The first two digits are the ordinal number of the week, and the second is the year of manufacture. That is, number 4215 indicates that the kit was produced in the 42nd week of 2015.

Color marking of tires

To facilitate the mounting of wheels on rims, manufacturers sometimes equip with additional color marks that carry their own information. How to decipher such icons. below.

Tire wear indicator

The location of the wear indicator can be indicated on the side of the tire by a small TWI lettering, a triangle, or some other icon. The indicator itself is usually a bridge in the groove between the protectors. When the tread wears off and its height is reduced to the height of the indicator, it means that it is time to change the tire. There may also be a drop indicator on the tire. When this drop wears off, the tire stops resisting aquaplaning.

Winter tires have an additional indicator. a snowflake. The winter indicator is higher than the “summer” one, and when the tread wears off to the “winter” indicator, the resistance of winter rubber to sliding on ice and snow completely disappears, and it is time to change it. Well, or you can “skate” like a summer one. Some manufacturers equip their tires with a digital indicator, which is performed as a number on the tire. As soon as for summer tires the figure is erased to 1.6 mm, and for winter tires. up to 4 mm (the minimum height of the tread pattern), it is time to change the tires.

Designations on the tires what they mean and what kind of rubber is better to take?

All car tires have markings, and now we will figure out what each letter and number stands for. This is necessary in order to find the right rubber for your car, which will suit your driving style, etc.

READ  What is the pressure in the wheels of a bicycle 26

What do the numbers and symbols on car tires mean??

What do the numbers and symbols on car tires mean??

When choosing car tires, pay little attention to cost and appearance, you should carefully study what is written on the side of the tire. The first thing to pay attention to is the dimension.

For example, the designation 195/65 R15 says that the tire width is 195 mm, the tire height is 65% of the tire width and R15 is the mounting diameter in inches. This is followed by the marking of the speed indices and the maximum load indices. The tables below will help decipher these values.

Maximum load index table.

For example, the 91T designation informs us that the maximum speed for this tire should not exceed 190 km / h, and also that the maximum load is not more than 615 kg. Try not to experiment with tire sizes, it’s not in vain that the manufacturer recommends certain sizes. After all, it is on them that the maximum driving characteristics of your car are achieved. When beading a tire, be sure to take into account the direction of rotation, usually indicated by a stylized arrow.

Different types of designation of the direction of rotation

On winter tires there will be a snowflake sign against a mountain background, as well as the letters MS, M stands for “mud”, S for “snow”

Perhaps the most important and unobtrusive designation is the tire production date. The designation is applied in the format “35.11”, which means that the tire was produced in the 35th week of 2011. Make sure that the tire is not older than two years, because the life of a tire is five years, then it loses its properties.

Red indicates the heaviest part of the tire, yellow opposite is the lightest, and white the thinnest part of the sidewall of the tire. Longitudinal color stripes on the tread, contrary to popular belief, indicate the type of workpiece rubber compound. Such marking is used only so that at the production stage workers do not confuse the blanks of future tires.

The ridges on the tread are wear indicators. It is not recommended to use the tire if the wear indicators are equal to the tread pattern.

Maximum tire pressure

The MAX PRESSURE marking (the inscription itself may not be there, but only numbers stand) indicates the maximum pressure that the tire can withstand. This tire has a maximum pressure of 350 kPa (kilopascal). Translated into atmospheres, this will be 3.5 atmospheres (at the rate of 100 kPa = 1 atmosphere). Pressure is also indicated in PSI (Pounds Per Square Inch). To translate PSI into atmospheres, you can look at a special table:

Please note that the tire does not indicate the recommended pressure, but the maximum that the tire can withstand!

What the numbers say

There are various marking systems, European and American, the latter being of two types. Tires of European manufacturers are widespread in our country, therefore, the marking adopted by them will be considered below.

The most understandable is the designation of the manufacturer, for example Michelin, Pirelli, Bridgestone or others. No explanations are required here, each driver decides for himself what to choose, depending on financial capabilities. The cost of tires from leading manufacturers is higher than from little-known.

For a better understanding, let’s analyze a typical marking, for example 195/70 R15 89H.

    First, the tire size is indicated, in our example it will be 195/70. The 1st digit indicates the width of the tire in mm, the 2nd is the ratio between the height of the tire and its width, expressed as a percentage. What in these numbers refers to what will help to make out the drawing.

In fact, this ratio means that with the same width, the higher will be the tire with the higher value. By the way, it allows in some way to compare different tire models. If you decide to put wide tires on the road for greater stability of your car on the road (instead of 195/70, choose 205/70), then it is necessary for Honor that the new ones will be higher, respectively, and the car will rise above the road, but this may already be unsafe. In some cases, it happens that the second digit is missing, that is, the marking looks like 195 / R15. This is the designation for a full-profile tire when the height-to-width ratio is 80%. Practice has established that in the conditions of our roads, the use of tires with a profile height of less than 50 is quite dangerous.

  • Index R. design, means that the tire is radial.
  • Index 15. diameter (in inches) of the disc for installation, that is, this is how the inner diameter of the tire is indicated.
  • An indicator of the permissible load, for example 89. This means that the permissible wheel load should not exceed 580 kg. The specific value is determined in accordance with the given table according to the index indicated on the bus.
  • It is worth noting that it would be a mistake to determine the total permissible load by multiplying the obtained figures by 4. It means the maximum load, and the operation of any device in the limit mode is an extreme case. Therefore, first of all, it is necessary, at least, to reduce the value of the permissible load by 20%. Well, it is also necessary for Honor that the car may have different permissible axle loads. this is usually indicated in the operating instructions.

    Speed ​​index, in example H. Shows the speed at which the tire can be driven. The specific allowable value is determined using reference data, in our example. 210 km / h.

    Speed ​​Index Table:

    94 ?? load index. This is the maximum permissible load per wheel. For passenger cars, it is usually made with a margin and when choosing tires is not a decisive value, (in our case, ID ?? 94 ?? 670 kg.). For vans and small trucks, this parameter is very important and must be observed.

    Bicycle tire manufacturer

    Everything is simple and clear here. Any self-respecting manufacturer will write its name on the tire.

    By the way. Some information about the labeling of Soviet bicycle tire manufacturers.