# How to determine the tire pressure of a bicycle

## Influence of pressure on ride quality

The correct tire pressure is a specific parameter for each bicycle and for its rubber. The bike owner creates a certain amount of pressure based on the quality of the roads where he rides, or the lack of them. Riding preferences and physical fitness play an important role. The minimum and maximum pressure is determined by the supplier of the specific rubber.

The increased pressure in the wheels allows the cyclist to save energy. By improving the movement of the wheels, a person can lengthen or complicate his route.

The pressure exceeding the limit entered by the manufacturer is the reason for the puncture of the chamber from the inside of the rim. The side of the rim where the spokes go and where the protective rubber band runs will eventually break through the chamber with one of its side edges.

Below a lower pressure limit, the pressure will lead to a breakdown of the chamber, or “snakebite”. It looks like two adjacent holes. The rim breaks through the camera in two places at once when the wheel hits an obstacle.

The wheels must be inflated within the pressure specified by the manufacturer. In this case, the tire adheres perfectly to the road surface or to the road without any surface. The camera remains unharmed for many hundreds of kilometers.

The chamber pressure range is indicated on the sidewall of the tire. For example, a mountain bike tire says 1.95 inches wide. Inflate the wheel and measure the width of the tire using a ruler and two squares or a caliper. If the width coincides with the specified value, and the wheel is elastic and firm to the touch, then you can ride. The width of the inflated wheel is not indicated on the camera. in this example, without a tire, it can inflate not to 1.95, but, say, to 2.1. When the camera already “sits” under the tire, the nipple itself takes on the load from the air expanding it from the inside.

The valve of the nipple. the spool. is reliable enough not to bleed air when the wheel of a stationary bicycle is inflated or when it is under working load during the ride. The pressure rating while driving is already taken over by the tire, and not by the chamber. The tire prevents the tube from swelling even further. The tube is securely held by the tire due to the shape given to all the rubber by the cord and bead cable.

If the pressure is too low, the bike tire will sink under the weight of the cyclist. It blocks the camera, causing it to abrade, making it more penetrable. Excessive pressure at high speed will rupture rubber when hitting a bump, stone, rails or crack across the road, when driving on overheated asphalt.

The norm for road bikes is 8-11 atmospheres (bar), depending on the specific tire, the weight of the bike and cyclist, average and extremely high speed. Here the general rule works: pumping up the manufacturer’s recommended pressure (maximum 0.5 atmospheres), you will quickly and safely reach from point A to point B of your route. You are unlikely to be able to squeeze 10 atmospheres with a hand pump. Use a hand or foot pump with a pressure gauge. If your pressure limit is 9.5, then upload 9 and drive quietly at maximum speed.

All chambers gradually poison the injected air through their micropores. Part of it is also vented through the old nipple that has been loosened from thousands of pumping. Rubber itself allows molecules and atoms of atmospheric gases to pass through: compare the molecular size of the vulcanized polymers (this is a long chain) of which the chamber is made, and the sizes of the nitrogen and oxygen molecules. The longer you use one and the same camera, the more intensely it poison the air. gradual stratification, drying out of the rubber structure does its job. For example, for “KamAZ” wheels, pumped over due to congestion, eventually burst at full speed (one at a time, as the rubber resource is depleted).

A road bike with 10 bars in wheels, traveling 40 kilometers per hour and carrying a biker weighing 80-90 kg, undergoes the same thing. During the week, the working pressure in the wheels drops by about 1.5 atmospheres. After feeling the wheel after a 300-kilometer marathon, you are unlikely to feel that it has lowered, but the pump pressure gauge (or car compressor) will immediately indicate this.

If you do not have your own pressure gauge at hand, you can pump up the wheels of a bicycle at any service station for free using an automatic compressor.

It inflates a bicycle wheel in a few seconds, and when the set pressure is reached, the automatic switches off the air blower. A bicycle owner’s own pump is not only a portable tool that allows you to inflate a wheel after a rubber repair. For cycling professionals, a pump is a tool that they use regularly, and often even forcedly. The lot of a sports bike is fast driving (up to 40 km / h), racing on highways and cycle tracks. Pumping its wheels below the average pressure will lead to a quick breakdown of the chambers. Broken, cracked, rough, crumbled and bumpy asphalt is an additional problem.

If you inflate the wheel of any bicycle 2-3 times higher than the maximum value, then this pressure is guaranteed to explode the tube with the tire after the first hundred meters of travel. But even if the rubber could withstand such pressure, the rim would easily get severe damage. “Top” pressure is not the one at which the tire bursts, but the one at which the wheel itself breaks.

## What should be?

Pressure standards are different for each type of tire.

### For city bikes and mountain bikes

For a teenage or adult road (or mountain) bike with a wheel diameter of 24, 26, 27 and 27.5 inches, a pressure of 2.2-4 bar is considered optimal. But a road bike can withstand tire pressure up to 5 atmospheres. Exceeding this value will damage the rim on the first bump or explode the camera after acceleration over 30 km / h, sharp braking. A wider rim holds the tube better than a narrower rim. The more elastic the tire is, the more pressure it may need. And this does not mean that it will break with the maximum value.

Maintain a fine line between traction and rolling. Inflated to maximum pressure, the tire will roll very well. And yet, the grip will deteriorate sharply, since we are talking about a much lower speed. 5-30 km / h, and not 30-50. With a pressure below 2.2 atmospheres, the tire will noticeably wash out. Crossing and cornering balance will also suffer. The very first bump, passed at high speed (from 25 km / h) will lead to a “snake” breakdown.

The narrower the tire, the more pressure it will need. The above values ​​for “mountain” and “road” tires are suitable for a cyclist weight of 80-85 kg. The heavier the rider, the more wear-resistant rubber he needs, since the extra weight of a person requires more pressure. For dirt roads, off-road and asphalt, adjustments are also made.

## Bicycle tire pressure: what should be and how to swing?

The quality of cycling depends on the pressure in the inflated tire. Insufficient compressed air pressure in the wheels leads to more frequent punctures and breakdowns in the tube and tire. Excessive. to rubber abrasion. The optimal tire pressure can be determined based on your experience with proper cycling and manufacturer recommendations.

## In what and how is it measured?

Bicycle tire pressures are measured in pounds per square inch, pascals, and atmospheres (bars). The atmospheric pressure of the Earth at the edge of the ocean level reaches almost 1 bar. This unit serves as the value to be multiplied by the factor indicated on the wheel. Calculation formula: 1 atm = 101325 Pa = 1 bar. Pounds per square inch is an obsolete measure. Bar. too, but it is firmly associated in the memory of people with the value of the pressure of one earth’s atmosphere (value at sea level). One bar equals approximately 14.5 psi.

The number of bars rarely exceeds 10 units. The number of pounds per square inch is sometimes more than 100. The number of kilopascals is a three-digit (but can be over a thousand) number. Kilopascals are converted to bars or pounds per square inch. According to the above formula, the cyclist inflates the wheel. Deviation from the recommended range of values ​​will result in a high accident rate. You can convert kilopascals to megapascals (MPa) by dividing the number of kilopascals by 1000.

## What is written on the tires

The secret to making the right choice is very simple: just look at the inflated wheel. Next to the information about the size of the tire, there will also be information about the permissible pressure range in the chamber.

Why is this information not shown on the camera itself? Because in it the only point subject to real stress is the nipple, and its mechanism is very reliable. Otherwise, the normal pressure, which increases by an order of magnitude during fast skiing, is taken by the tire, and how much it will be compressed is the main limitation.

So, if the pressure is too low, the tire will break closer to the rim, bite the chamber, leading to a breakdown, and if it is too low, it may just burst on one of the bumps or when driving on hot asphalt.

## Bicycle tire pressure

How much inflate the wheels? Many cyclists ask this question quite often. All well-known tire manufacturers indicate the size of the recommended pressure on the side of the tire. Most often this figure is in the range from 35 to 60 psi (from 2.38 to 4.08 atmospheres).

A common mistake many novice cyclists make is overpressure in mountain tires or insufficient pressure in the wheels of a road bike.

There are factors to look out for when looking for the ideal tire pressure:

Cyclist’s weight. The performance of a tire at a given pressure depends on the weight of the rider. For example, a 66kg rider may find that 2.38 psi for a 26×2.25 tire is too high and grip is not good enough. Conversely, a 113kg rider may find that their tires are under-inflated and therefore bend and deflate.

The table shows the inflation data for a mountain bike with a tire width of approximately 2 inches.

Tire volume and pressure are two inextricably linked metrics. The volume of the tires determines how a certain pressure will appear to you. For example, a 700 x 25 mm tire inflated to 2.38 atmospheres per square inch will be practically flat, while a 26 x 3.8 inch tire inflated to the same 2.38 atmospheres will feel firm to the touch. the wheel will bounce. on uneven surfaces, rather than absorb them.

Much depends on the area. If you ride mostly on rocky tracks, it is better to inflate the tires a little more in order to avoid tire deflection and damage to the side section.

1.) Primer, potholes. inflate to an average value (guided by the readings on the tire) or slightly less.

2.) Asphalt, rolled paths. pump almost to maximum.

Your riding style is just as important as the terrain you are driving. The more aggressive the riding style, the more the wheels need to be inflated. Are you trying to choose the flattest sections of the track, bypassing the hills, or do you like to drive forward with indomitable energy? Do you like to keep the wheels on the surface or do you like to bounce on the bike, overcoming obstacles??

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Rim width plays an important role in determining the lowest possible pressure without sacrificing efficiency. A wide rim holds the tire better than a narrow one. It allows you to use lower tire pressure without sagging.

The design of a tire affects how it behaves at a given pressure in about the same way as the weight of a cyclist. High TPI tires are more flexible. TPI is the amount of nylon fibers per square inch of tire base. Low TPI tires have better puncture and tear resistance but are heavier. Higher TPI provides better traction, offering a smoother, softer ride and lighter construction. Typically, TPI values ​​range from 24 to 130.

Typically, tire pressures range from 35 to 48 psi (2.38 to 3.26 atmospheres). This pressure provides control over the road and maximum grip of the tires with the surface. An over-inflated tire to 50. 60 psi (3.40. 4.08 atmospheres) reduces ride comfort because the tire has less contact with the road.

When riding on asphalt, an inflated mountain bike tire wears out very quickly.

An insufficiently inflated tire 28. 32 psi (1.9. 2.17 atmospheres) is also fraught with danger. Because of this, you can easily punch through the camera by hitting a rock or simply hitting an uneven track. Under this shock load, the chamber is clamped between the rim and the obstacle, which can cause a “snakebite”. It will be difficult to fix a puncture of this kind. There is also a high probability of damage to the rim itself, this can entail expensive repairs or even replacement with a new one. It should be borne in mind that a badly inflated tire on a steep bend can be “ripped off”, and this can cause a fall. Most often, a breakdown occurs on the front wheel and is accompanied by a loud bang of the camera, as it easily bursts, having lost the protection of the tire.

Attention! Do not exceed the pressure stated by the manufacturer on the tire sidewall!

On surfaces like snow and sand, inflated wheels will respond better. In extreme heat, when driving at high speed, it is better not to inflate the tires to the maximum, as there may be overheating of the wheels. In winter, the wheels need to be inflated more, otherwise there may be damage to the tires and the tube from the cold.

Road bike wheels should be inflated to 95-135 psi (6.46. 9.18 atmospheres), as the air volume in them is less than in mountain bikes.

### How is blood pressure measured?

It is customary to designate pressure in three units of measurement:

• Psi. pound-force per square inch. pound-force per square inch;
• BAR. bars, usually equated to measurement in “atmospheres”;
• Pa. pascal.

### Bike Tyre Pressure Explained | Road Bike Maintenance

Since many tire manufacturers focus on the American market, the Psi designation is most often found. In English-speaking sources, it is usually simplified to “pound”, or pound, that is, when they say that a pressure of 2 pounds, they mean Psi. This unit of measurement is outdated, used only in the United States, but, as they say, “more alive than all living things”.

Bars are also obsolete units of measurement, but are actively supported in Russia and many other countries, incl. European. This unit of measurement is actively used, as it has something in common with the “atmosphere”, which is quite convenient for measurements.

Pascal is the only metrically correct unit on the list, but rarely used in bicycle designations.

The ratio between all units is as follows: 1 Bar = 100,000 Pa = 14.504 Psi.

### Markings

What do they write on the tires? For example, (2.38-4.0) is clearly atmospheres, or BAR, and (95-135) is Psi. If the figure has more than 3 digits or the prefix “k” (kilo), we are talking about metric Pascal. Most often, the desired value is located under the size designation and is duplicated in BAR and Psi in the form of a range, clearly indicating to what pressure you can pump.

Actually, the manufacturer indicates the range within which the tire can function, then. the freedom of the cyclist.

The norm for road bikes is 8-11 atmospheres (bar), depending on the specific tire, the weight of the bike and cyclist, average and extremely high speed. Here the general rule works: pumping up the manufacturer’s recommended pressure (maximum 0.5 atmospheres), you will quickly and safely reach from point A to point B of your route. You are unlikely to be able to squeeze 10 atmospheres with a hand pump. Use a hand or foot pump with a pressure gauge. If your pressure limit is 9.5, then upload 9 and drive quietly at maximum speed.

All chambers gradually poison the injected air through their micropores. Part of it is also vented through the old nipple that has been loosened from thousands of pumping. Rubber itself allows molecules and atoms of atmospheric gases to pass through: compare the molecular size of the vulcanized polymers (this is a long chain) of which the chamber is made, and the sizes of the nitrogen and oxygen molecules. The longer you use one and the same camera, the more intensely it poison the air. gradual stratification, drying out of the rubber structure does its job. For example, for “KamAZ” wheels, pumped over due to congestion, eventually burst at full speed (one at a time, as the rubber resource is depleted).

A road bike with 10 bars in wheels, traveling 40 kilometers per hour and carrying a biker weighing 80-90 kg, undergoes the same thing. During the week, the working pressure in the wheels drops by about 1.5 atmospheres. After feeling the wheel after a 300-kilometer marathon, you are unlikely to feel that it has lowered, but the pump pressure gauge (or car compressor) will immediately indicate this.

If you do not have your own pressure gauge at hand, you can pump up the wheels of a bicycle at any service station for free using an automatic compressor.

It inflates a bicycle wheel in a few seconds, and when the set pressure is reached, the automatic switches off the air blower. A bicycle owner’s own pump is not only a portable tool that allows you to inflate a wheel after a rubber repair. For cycling professionals, a pump is a tool that they use regularly, and often even forcedly. The lot of a sports bike is fast driving (up to 40 km / h), racing on highways and cycle tracks. Pumping its wheels below the average pressure will lead to a quick breakdown of the chambers. Broken, cracked, rough, crumbled and bumpy asphalt is an additional problem.

If you inflate the wheel of any bicycle 2-3 times higher than the maximum value, then this pressure is guaranteed to explode the tube with the tire after the first hundred meters of travel. But even if the rubber could withstand such pressure, the rim would easily get severe damage. “Top” pressure is not the one at which the tire bursts, but the one at which the wheel itself breaks.

## What to pump up

Bicycle luggage requires maintenance and pumping very often. Even on the most “hardy” city and mountain bikes, it is required to check and pump up the camera every 2-3 weeks, since the air leaks not only through the nipple, but also simply through the rubber. High pressure “helps” air molecules find their way through an insufficiently dense chamber.

“City”, or, simply, budget bicycles, it is enough to pump up once every 2-4 weeks, mountain bikes. at least once every two weeks, road bikes. once a week, and road and sports bikes. before each trip.

Therefore, the pump is not only an emergency accessory that is used only when a punctured wheel is changed, but also a necessary part of the preparation for departure. Active cyclists should consider purchasing two pumps:

• portable. as part of an emergency kit or on long trips;
• stationary with a stop and a pressure gauge. for periodic maintenance of your tires.

By the way, an ordinary car pump perfectly takes the place of a stationary pump. It is also suitable for bicycles, shows, shows exactly how many atmospheres are pumped up, and does not take up additional space. Some people prefer to pump up on “professional” pumps at gas stations, but the lack of their professional tool can play a bad joke in the event of an unexpected situation or when you deviate from the standard route.

## Pressure effect

In fact, the optimal tire pressure of a bicycle is a purely individual parameter, which each biker varies within certain limits for himself: for his riding style, for the planned route and the current level of training. The limits are set by technological constraints, which we will consider further.

Here are the main factors to consider when choosing an inflation level:

### Bike Tire PSI: How Much Air Should You Put in Your Bike Tire? || REI

• high pressure gives “roll”. rolling speed, saving the strength of the cyclist;
• excessively high, in turn, can provoke a breakdown of the chamber against the rim from the inside;
• similarly, low pressure leads to “snake bites”, when a rim on an obstacle or bump pierces the chamber at two points at once and reaches the tire;
• low pressure prevents damage to mechanisms on numerous bumps;
• at low pressure better “grip” and easier to move on rough terrain.

Taking into account all the pros and cons, a single recommendation can be made: the wheels should be inflated enough to provide good traction and not damage the camera. For this, there are standards for what pressure is considered acceptable. We will consider them further.

## Standard pressure

Here are some tables that will help you navigate in difficult situations, namely:

• an unknown tire without markings was purchased;
• the marking is incomprehensible, the numbers are marked in unknown units.

## Bicycle tire pressure

A bicycle is a fairly well thought-out and reliable device. But with improper operation, even the highest quality elements and systems can fail faster than it would have happened naturally. Last but not least, this concerns the wheels. For example, how much the pressure in the chambers of the bike corresponds to a certain norm will depend not only on the comfort during the rides, but also on the service life of the tires.

### Average values

A certain average rate of pressure in the tires of a road bike designed for riding on good, flat roads is 6.46. 9.18 atmospheres.

For a mountain bike, this figure varies from 2.38 to 4.08 atmospheres. For off-road driving, the optimal pressure will be from 2.38 to 3.26 atmospheres.

As for the variation within the “limits of what is permitted”, in summer it is advisable to adhere to the lower limit so that the air in the chambers, heating and expanding, does not damage it. In winter, on the contrary, a tube inflated to the upper border will allow the treads on the tires to adhere more tightly to the surface. The pressure in the chambers must also be correlated with the weight of the cyclist. Experts believe that it is necessary to add about 1% to the average value, based on each kilo of cyclist weight over 50.

A common mistake many novice cyclists make is excessive pressure in mountain tires or insufficient pressure in the wheels of a road bike. There are factors to look out for when looking for the ideal tire pressure:

## How much pressure should be in the bike?

Many cyclists ask this question quite often. All well-known tire manufacturers indicate the size of the recommended pressure on the side of the tire. Most often, this figure is in the range from 35 to 60 psi (from 2.38 to 4.08 atmospheres).

The exact answer to this question depends on many factors. First of all, this is the expected area on which you plan to ride and the “profile” of the bike. High pressure is preferable if you are driving on asphalt, as it gives excellent roll, and low pressure provides strong traction on rough terrain. Riding style and weight of the cyclist also matter.

### Tire volume and pressure

Tire volume and pressure are two inextricably linked metrics. The volume of the tires determines how a certain pressure will appear to you. For example, a 700x25mm tire inflated to 2.38 atmospheres per square inch will be nearly flat, while a 26×3 tire. 8 inches, inflated to the same 2.38 atmospheres, will feel solid to the touch. the wheel will bounce on uneven surfaces, not absorb them.

Much depends on the area. If you ride mostly on rocky tracks, it is better to inflate the tires a little more in order to avoid tire deflection and damage to the side section.

• Primer, potholes. pump to medium (based on the readings on the tire) or slightly less.
• Asphalt, rolled paths. pump almost to maximum.

Your riding style is just as important as the terrain you are driving. The more aggressive the riding style, the more the wheels need to be inflated. Are you trying to choose the flattest sections of the track, bypassing the hills, or do you like to drive forward with indomitable energy? Do you like to keep the wheels on the surface or do you like to bounce on the bike, overcoming obstacles??

Rim width plays an important role in determining the lowest possible pressure without sacrificing efficiency. A wide rim holds the tire better than a narrow one. It allows you to use lower tire pressure without sagging.

The design of a tire affects how it behaves at a given pressure in about the same way as the weight of a cyclist. High TPI tires are more flexible. TPI is the amount of nylon fibers per square inch of tire base. Low TPI tires have better puncture and tear resistance but are heavier. Higher TPI provides better traction, offering a smoother, softer ride and lighter construction. Typically, TPI values ​​range from 24 to 130.

### Units

Typically, tire manufacturers indicate the limits in which the cyclist can vary the inflation of the wheels. In our country, pressure is usually measured in atmospheres (at).

This value is approximately equal to a unit like Bar, which is common in Europe. On American tires and products intended for the American market, the permissible pressure is indicated in Psi.

## Nipple types

It has already been mentioned that the nipple serves to keep air in the chamber.

Nipples are produced in three types:

Presta. sports; Dunlop. Bicycle Shrader. Automotive.

The oldest, once installed on Soviet bicycles, is a bicycle. It is rarely used these days.

Sports. the best option for mountain bikes, road bikes and hybrid, i.e. quite widely used today, including installed in simple models.

But the primacy is held by the automotive Shrader nipple. Its advantage is that it is easy to pump up the bicycle camera with it even at gas stations. In principle, the last two nipples can be purchased. In addition, manufacturers, taking care of lovers of cycling “rides”, produce universal pumps that are suitable for Presta and Shrader.

## Which company is the best camera?

The following companies have proven themselves quite well in recent years:

• Shwalbe and Maxxis;
• Kenda. in second place.

## How is the pressure measured??

It is measured in three units:

• bars. BAR. which equate to “atmospheres”;
• lb-force. Psi per sq. (inch);
• pascal. Pa.

Psi is an obsolete unit found only in America, nevertheless it is used more often than others, because manufacturers focus mainly on the US market.

The bars are also dated. However, in many European countries and in Russia they are supported, since they conveniently resonate with the “atmosphere”. Pascal is considered the only correct unit of measurement, but it is rarely found in bicycle designations. There is such a ratio between these units:

When written on the tire 2.38-4.0, it is the designation of atmospheres. When 95-135 is indicated, it is Psi in the marking, it is inches. Meaning Pascal, write three numbers or add “k”. the prefix kilo.

## How to determine the optimal tire pressure for your bike

How to choose a bike camera? This question worries those for whom the bicycle has become an integral part of life. No less important for them is the question of what pressure in the tires of a bicycle is considered optimal.?

The chamber is a closed rubber tube equipped with a nipple. It is designed to shape tires, and the tube also provides wheel elasticity and stability by trapping air.

Tires are selected depending on the specifics of the bike.

Their thickness is determined in accordance with the riding style:

• for riders, thin-walled tires are preferred. This way you can reduce the weight of the bike;
• for extreme riding, thick-walled tires are most suitable, which are more difficult to pierce.

Cameras are made of rubber and latex. The latter are lighter and their quality is higher.

Cameras are bought according to the diameters of the corresponding tires, and the nipple through which air is pumped in and removed is recommended to be purchased thin and light.

The size is indicated by two numbers. If there are numbers 40-559, then the diameter is 40, and the width is 559. To correlate the tube and the tire, you need to determine the parameters of the latter, for which there is a marking on the tire.

The size of the chambers is the first thing to look out for. Installing a tube larger than the tire is not desirable because it will chew.

The same is observed when installing a camera that is wider than necessary. If the dimensions do not match, the cyclist will face a problem with the wheel: a tube with a smaller diameter than the tire will swell and may even burst.

## How to care for your camera

Relatively recently, an invention has appeared that protects against puncture of the camera. preventive anti-puncture. This liquid of a rather thick consistency is poured into the chamber. When punctured, leaving it with air, it “clogs up” the hole, not allowing the tire to deflate.

There are already such cameras on sale with an anti-puncture poured inside by manufacturers. But, nevertheless, it is better to do it yourself, since there is no way to check the quality of the poured product.

You can also fix the puncture in a more traditional way. with a patch and glue. After the patch is dry, the tube must be checked, as well as the tire. for any residues of something sharp.

If the incision is very long, you will hardly be able to fix the camera yourself. But, perhaps this will be done by specialists working in bicycle workshops.

Much more serious is the problem of valve damage. It will not be possible to restore the camera either on our own or with the help of specialists. It needs to be replaced. It’s bad if there are eights on bicycle wheels. The repair will help preserve the cameras. Therefore, when planning a long trip, you need to take care of a spare tire so as not to rack your brains over how to replace a wheel on a bicycle.

Camera selection is extremely important for serious cycling enthusiasts. Amateur cyclists need a camera similar to the one supplied.

### Air pressure for different types of tires

If you have a half slick, the low pressure negates its benefits. The meaning of the semi-slick is that, thanks to the semicircular profile, the tire rolls on a hard surface with a smooth part of the tread. And only after hitting soft ground, the side part of the tread comes into play.

And if the tire is poorly inflated, then it will be flattened, and your half-slick will paddle with its lugs even on the asphalt. Therefore, in this type of tire we pump close to the maximum pressure.

Standard 2.1-2.3 inch cross country tires require a working pressure of 3-4 bar. Such rubber has not very pronounced lugs, it is the most versatile tire for those who ride in forests.

Tires for more extreme riding are 2.3 “wide and wider, and traction is very important here. The pressure is calculated experimentally so that the tire does not break through on drops and hard descents.

## Fatbike tire pressure

The fat bike is designed to ride on loose surfaces, its huge, large-volume tires must flatten over bumps, this is achieved by low pressure.

Fat is the perfect bike for winter, so let’s talk about riding in the snow. For a rider weighing 80kg, the following figures may be acceptable:

 10psi Rolled snow, paths 8psi Thick snow 6psi and below Loose snow

Fat rolls much better on loose snow if you pump less than 5psi. But reducing the pressure below this line for tube tires can be a bad decision. the bike starts to obey the steering wheel poorly, “floats”, the nipple can break or shear due to the rotation of the tube. Therefore, I recommend switching to tubeless wheels for your fat bike, the bike will roll better and more stable at extremely low pressure.

In addition, do not forget about such a trifle that since you have much less atmosphere in your tires, temperature fluctuations will be reflected in real pressure. For example, at home it was 7psi, went out to frost of 10 degrees, it became 4.3. Here is a table for you, by which you can calculate the approximate dependence on temperature:

 The pressure in the chambers depending on the outside temperature Indoor temperature, ° C Outside air temperature, ° C 25 10 five -five -10 -fifteen -twenty 740 Atmospheric pressure, mm Hg psi at room temp. psi outdoors depending on temperature four 3.0 2.7 2,3 2.0 1.7 1,3 1.0 4.5 3.5 3.1 2.8 2.4 2.1 1.7 1.4 five 3.9 3.6 3.2 2.9 2.5 2.2 1.8 5.5 4.4 4.1 3.7 3.3 3.0 2.6 2.2 6 4.9 4.5 4.1 3.8 3.4 3.0 2.7 6.5 5.4 5.0 4.6 4.2 3.8 3.5 3.1 7 5.8 5.4 5.1 4.7 4.3 3.9 3.5 eight 6.8 6.4 6.0 5.6 5.1 4.7 4.3 nine 7,7 7.3 6.9 6.4 6.0 5.6 5.2 10 8,7 8.2 7.8 7.3 6.9 6.4 6.0

## Why it’s important to inflate your tires with the correct pressure

• The more inflated the tires, the better it rolls, the less fatigue
• The heavier the cyclist, the more you need to pump
• The more the tires are inflated, the more it shakes on bumps
• If the pressure is weak, then moving over the curb, you can punch the chamber against the edges of the rim (snake bite)

And now the logical question is how to find out within what framework you need to pump, how many atmospheres to pump specifically? The pressure in bicycle tires is measured in atmospheres (BAR) or PSI, and most often, the permissible range is written on the sidewall of the tire in PSI (one atmosphere is equal to 14.7 psi). Here is the average table for the average cyclist riding no extreme, on asphalt and dirt roads.

This information is enough for you to ride comfortably enough, while the tires will not suffer from over-pumping or under-inflation. Well, for those who care about details, we go deeper.

## Mountain bike tire pressure

Off-road bikes are a little more complicated. The point is, here you need to strike a balance between grip and coast. The more inflated the tire, the better it rolls (on a flat and hard surface), but due to the rigidity it cannot “lick” the surface. the grip deteriorates.

High pressure maintains the semi-circular profile of the tire, while maximum grip is possible when the full contact patch is involved. In other words, the more the tire “flattens”, the better for cross-country ability and control. On the other hand, if you pump too weakly, the roll will suffer and the same “snake bite” is possible.

Since basically all chamber mtb rubber has an allowable pressure range of about 2-4 atm, then I would say that the working pressure is between 2.2 and 3 atmospheres for an adult man weighing from 75 to 90 kg. It is impossible to say more precisely. there are a lot of factors, you need to experiment with a specific tire and a specific trail where you ride.

Different tires behave differently at the same pressure, and the behavior also depends on the width of the tire, it is believed that less pressure can be pumped into a wider one. The weight of the cyclist is very important, for obvious reasons.

Take a pump with a pressure gauge with you and try to find the lower pressure limit at which the tire still does not break. Then try how the bike rolls at that pressure. Add air if needed. You need to find a middle ground for both soil and asphalt.

With bikes for asphalt roads, everything is simple. the more pressure, the better the roll. Look on the sidewall of the tire, there must be written a valid value, in psi, or in bar (atmosphere). If the maximum value, for example, 8 Bar, then score 7.5 and enjoy the speed.

I highly recommend getting a good floor pump with a pressure gauge (I bought it here), because pumping up a road tire with a portable pump is still a torment, even if it is capable of delivering high pressure.

I will add that the air is etched through the rubber itself, and in about a couple of weeks the pressure drops by 1-2 atmospheres. You can’t feel it with your fingers, so a floor pump with a pressure gauge could not be more useful.

If you inflate a road tire below average, you can catch a tube breakdown called a snakebite. This happens when the wheel hits a hard object and the tire hits the rim. The result is two small holes that look like a snake bite.

## How much pressure should be in bicycle tires

It would seem that it could be simpler. pumped up, crumpled with your fingers, and drove off. But no, there are some subtleties here. Tire pressure is the most important factor in rolling, floatation and bike handling.

I am not deliberately touching tubeless tires yet, because they are installed on more expensive bikes, and this is a topic for a separate article.

### How much to pump in tires in winter

If you ride a bike in cold weather, then it must be borne in mind that in the cold, the pressure drops a little, so at home pump about 20% above normal so that everything on the street comes into balance.

Here I described how to choose the right bike tires for different riding styles, I advise you to look.

I would not want readers to imagine a picture of a cyclist with a pump, which only does what sets different pressure under different conditions.

In fact, finding a middle ground is quite simple, you just need to devote half an hour. I advise you to pay attention to this issue, if you are a beginner, then most likely you have not even thought about it.

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Yes, the right pressure is very important. As recently as yesterday before leaving, I did not check it, I went. As I said, I have a MAXXIS Larsen TT, and it has very soft sidewalls. I feel that the rear wheel is driving at cornering speed. I drove on the road to a tire fitting to check the pressure. I usually ride at 3.5-4 atm, but here it is only 2.5 atm. That immediately unpleasant sensations that the wheel is about to break off or the tire will bend.

An expensive pump with a monometer for MTB in our time is superfluous. At any, well, almost any, gas station, you can pump the required pressure. And for minor repairs, a mini-pump from the same tea house is enough, fill 3 and get to the gas station.

I do not agree that the floor pump is superfluous. It is not always possible to drive to the gas station or it is not so close to check the pressure and pump up the wheel. And you don’t have to buy an expensive pump. Accidentally in Decathlon I got on a sale and bought an excellent floor pump there for 500r. With a long hose, high, not very thick working chamber, which makes it easy to pump high pressures, aluminum body and footrest, which are rare in cheap options

I like more pressure. I swing 4 atm before, 4.2 back. Kenda rubber 8 small blocks 2.3 ″ (:)), I weigh 87-89kg, I drive both on the ground and on asphalt. Rows normally on mud, but sand is death. Immediately I burrow (well, it is understandable :)) So I shake so that the rubber does not play on turns, but it is bouncing and rolls on pebbles, but very precise control. At high speed (50-70 km / h) it is very noticeable. Then, and at a lower speed, I began to notice this effect. Well, he began to pump in the area of ​​maximum pressure. By the way, with intensive pedaling, the pumped rubber does not start to swing.

This is where you accelerated to 70 km? Not a rope behind the car? Or when he was dropping off the balcony?

maybe he has a gravel bike. Ie shoser with spike. that can roll 50-70. ON MTB, yes, behind a truck only or from a hill, or on a cigarette standing next to a bike

A floor pump is a thing! I recently bought myself, with a large working chamber, a pressure gauge. Because There are several bicycles in the family, and on mine there are also several sets of rubber, which I change depending on the type of coating, it saves time and effort perfectly, plus on different bikes there are also different types of nipples, but here there are two separate heads. do not twist anything it is necessary, conveniently, in general By pressure, I concluded that I pump the toothed rubber of Richie to 3.5 and it is nice, soft and tenacious, though not very fast, and I pump Marathon Supreme slicks up to 5 atm, on asphalt it’s a fairy tale, although recently I I have already started to poke into the ground in them because the slicks are high 622 × 50 But with my wife’s bike it is more and more difficult, it is much easier than and here I do not know whether the rubber is to blame or the fork, she complains that she was driving like on sand, even on asphalt, the descent of the rubber saves a little, but only a little.

Abysmal, with MAXXIS, these are known problems. in the sense of soft sidewalls and insufficient pressure. I have more experience with MAXXIS Overdrive, now here is Gipsy, but the story is the same. As tires they are good. tenacious, do not slip even on wet and dirty asphalt, even though they are slicks. But they cut through the sides when under-pumping and overloading. To prevent them from driving, it is advisable to select a width that fits the rim, and not set, say, 2 inches per 18 mm rim landing width. Even the stock Specialized is guilty of this. That is why I prefer Schwalbe CX Comp or Road Runner from semi-slick tires. because these are mass tires, they are produced in a wide variety of widths, and it is not difficult to select the width for the rim (remove drift). Of course, no one canceled the correct pumping

Sergey K, I didn’t want to write about this directly in the article, but I also had problems with Maksis. Exactly what you say. Therefore, I cannot recommend them to readers.

Sergey, so if he drives, on the asphalt, is it on the contrary, underpumping? Or what is meant by “drives”?

chiba, will be. simislik, but manufacturers do not always indicate this explicitly. So it’s better to look with your eyes.

Abysmal, I also cannot imagine life without a floor house pump.

It is unlikely that it is under-pumping, because pumped up to 4 and gradually lowered to 2, as the descent it drives less, but the roll-off falls. Based on her description, it’s like riding on ice. I really sin more and more on the fork, the bike has been used for 3 or 4 years, and before this season it was used very little, now something happened to the fork. it just bounces back if you squeeze it, in general, if you press the handlebar and release that front wheel will jump, and if you lift the wheel into the air and throw it, then the lead will jump, the fork there is a simple SR XCT, i.e. a fork-simulator, but on mine, too, an extremely simple RS XC28, everything is completely different (it does not jump). I’m thinking, maybe the elastomer has broken (it happens at all or not, I don’t know) or it’s stretched out so it just dangles inside.

“If you press the steering wheel and release, the front wheel will jump, and if you lift the wheel into the air and throw it, the bike will jump, the fork is a simple SR XCT”. the damper cartridge in the right leg died. Nitrogen left from the chamber or glass oil, or both. This is only to replace the entire plug. There are no spare parts for this, and the cartridge is non-separable and maintenance-free