Decoding bicycle tire markings

The abundance of lettering on modern bicycle tires is sometimes confusing to riders. In addition, all these numbers and letters do not always accurately reflect the actual dimensions of the tire. Different manufacturers use different wheel size designation systems. So the user needs to know the decoding of the marking of bicycle tires, so as not to buy a "pig in a poke".

This is the first thing that comes to mind. However, manufacturers are cunning and indicate the approximate dimensions of the wheel. This is especially true for the usual 26 and 28-inch wheels. The fact is that this is the outer diameter of the tire, and the landing size is completely different.

To correct this outrage was invented ETRTO system (European Tire and Rim Technical Organization, European Tire and Rim Technical Organization). In this system, only 2 sizes are indicated - tire width and rim diameter... An example of such markings: 37-622. Here the numbers mean that 37 mm is the width of the tire, 622 mm is the inner diameter. To avoid errors, the rim diameter is usually indicated on the wheel rim.

The numbers on the tire can be 3, for example, 28x1.4x1.75, where 28 is the outer diameter of the tire, 1.4 is the height of the tire, 1.75 is its width.

In both cases, the fit is not specified, but the dimensions are approximate. In addition, the size 1.75 and 1 ¾ inch are mathematically the same, but not always the same in reality. Be careful.

To avoid confusion, buy new tires after the old ones. Also choose models in which the designations in inches are duplicated by the ETRTO system marking.

Sometimes used on European tires French notation system. The width and outer diameter are indicated by numbers, and the landing one by a letter. For example, 700x35C. 700 mm - outer dimension, 35 - tire width. The letter C corresponds to a bore diameter of 622 mm. The closer the letter is to the beginning of the alphabet, the smaller the width. These markings are not used on mountain bike tires.

The Soviet system of marking was similar to ETRTO, but the first number indicated the fit size, and the second - the width of the tire. For example: 622-37. In most cases, this is sufficient. If not, then specialists will help you.

This table will help you fully decipher the tire sizes.

Also, different types of bicycles use different diametrical wheel sizes. The most popular sizes in inches are shown below:

• 16, 18, 20 - children's and folding bicycles;
• 24 - teenage models;
• 26 - mountain bikes;
• 26, 27, 28 - city, road bicycles, niners.

It is not worth buying a bike if the wheel diameter is different from these dimensions. Otherwise, it will be difficult to find the right tires and tubes.

There are tread patterns for different categories of roads. They are of several types.

• Slick. Smooth pattern, suitable for road and racing bikes.

• Half slick... Good roll-off is combined with good flotation and is used on most mountain and city bikes. The main feature is a smooth treadmill and jagged edges.

• Mud protector... Aggressive pattern for better traction on difficult surfaces and soft soils. It is used on downhill bikes and other off-road vehicles.

• Winter drawing. "Angry" tread with spikes for riding on snow or very soft surfaces. Typically these tires are fitted to fat bikes.

In addition to sizes, tires also differ in the composition of the rubber - the compound. The softer it is, the better the grip and handling, but the less the resource. Its composition is deciphered by a colored strip that runs along the entire tire along the tread track. A total of 4 colors are accepted.

• Red. Hard rubber, it rolls well.
• Blue. Rubber of medium hardness, good speed properties are combined with tenacity.
• Orange... Soft rubber for unprepared surfaces.
• Purple. Ultra soft compound for off-road competition.

During manufacturing, the tire is reinforced with special threads, usually nylon. By the way, this is often indicated by the inscription on the sidewall. The more of these threads, the thinner they are, and the tire is lighter, but more expensive. This value is denoted abbreviation TPI.

For cross-country disciplines, the TPI must be 120 or higher. This is necessary for good roll-off and precise handling.

For downhill and enduro TPI no more than 40-60. Thanks to the thick threads, the tires are very strong but heavy.

A low TPI is not always indicative of tire strength. In cheap models, there may be few threads, but they will be thin, and the tire is still heavy.

Remember it is the tire that holds the pressure of the tube and transmits vibrations and shocks to the frame. Do not take a tire that is not strong enough.Saving will still not work, since the tire will simply break from excessive load. And well, if not during a stunt or race.

In addition to the strength of bicycle tires, the tread stiffness is also standardized. The more rigid it is, the higher the roll and speed, but the lower the grip properties. It is not difficult to understand the values ​​of the tread stiffness:

• 40–45a - soft tread for downhill competitions;
• 50-60a - Medium soft tread for mountain bikes;
• 60–70a - Tough cross-country tread, minimal puncture probability.

Manufacturers equip some tire models with an anti-puncture layer made of viscous rubber or Kevlar. In addition to protection, this layer heavily makes the tire heavier and reduces roll. The probability of puncture is reduced, but still remains, especially near the sidewalls. The presence of such a layer is indicated by the inscriptions Puncture protection, Puncture resistance, Flatless, Anti-flat and others.

Tires with different types of sidewalls have been created for different riding conditions. There are 2 such types in total.

• Liteskin. This is a lightweight and thin sidewall. Designed for racing or fast driving on flat and hard roads without obstacles.

• Snakeskin. Stiffer and more protected sidewall for heavy duty use with the ability to cut sidewalls. These can be stones or other objects.

Such notation is used by Schwalbe... For others, you can see other names, but the essence does not change.

Cord is a rigid collar that fits over the rim. It can be steel or Kevlar. Steel is heavier, but also cheaper. Kevlar is lighter, can be folded and improves speed performance. The difference in price between such tires is 2 or more times.

The tire may have a recommended pressure stamped on it. Usually there is an inscription Inflate to min ... max, which indicates the lowest and highest pressure in the wheel... Units are also shown.

There is usually an arrow on the side to indicate the direction of rotation. She subscribes Rotation or Drive.

There are tires with a reflective stripe. On their sidewalls there is the Reflex inscription.

Choosing a tire that meets all the requirements can sometimes be problematic. Knowing the basic ways of marking your tires will help you determine the right tire model and not waste your money. Large shops even have cross-sectional views of bicycle tires to showcase how they are constructed.

Also, a competent seller himself will offer you the desired model based on the operating conditions. If its labeling clearly does not correspond to the knowledge that you acquired from this article, this is already a reason to think. The seller may be cheating on you.

For more details on tire sizes, see below.