How many atmospheres should a bike have? What pressure should be in bicycle tires? Determining the symbols on a bicycle tire.

The degree of inflation of bicycle wheels depends on the type of tires, bicycle, weather season, characteristics of the road surface, the weight of the cyclist and his riding style. For a beginner, understanding the intricacies of adjusting the air pressure in bicycle tires on your own is quite difficult. And it is necessary to do this, because the comfort and safety of riding, as well as budget savings, depend on the correctly selected pressure in bicycle tires.

Let us consider in order the main issues related to the topic of selecting the individual optimal pressure in bicycle tires.

How to measure pressure

Air pressure in bicycle tires is measured in Atmospheres, Bars, Psi and Kilopascals.
The atmosphere is used in Russia. It is almost equal in size to the Bar, so in practice these units are interchangeable. 1 atm. = 1 kgf/1 cm2 = 1.02 bar.
European brands more often use Psi in accompanying documentation for their bicycle equipment. 1 psi = 1 psi
When marking tires, Kilopascals may be used to indicate the minimum and maximum permitted pressure.

In practice, units of measurement are converted from one to another using the formulas:

• 1 psi = 0.068 atm
• 1 atm = 14.696 psi
• 1 atm = 101.348 kPa
• 1 bar = 0.98 atm

1 bar = 0.98 atm

You can also use ready-made tables of basic values:

How to measure pressure? How to inflate bicycle tires

In the absence of a better way to determine the degree of inflation of bicycle wheels, you can, of course, resort to the old fashioned method - squeeze the tire with your fingers. But since the rubber stops bending after a couple of atmospheres, and the strength in everyone’s fingers is different, it is impossible to reliably determine the air pressure inside the tire using this method.

To measure tire pressure parameters, special devices are used - pressure gauges. Today there are a great many of them. There are even pumps with built-in pressure gauges, but their readings are not very accurate, so it is advisable not to skimp and buy a good device separately.

There are mainly three types of pumps for inflating wheels:

Manual. With hose or integrated head. The main advantage is affordability. With an integrated head they are more efficient, but both types produce a small volume of air and require significant effort to inflate the tire;

Foot. Inconvenient for road bike owners; it is difficult to inflate a high-pressure wheel with them. Requires special brass adapters for bicycle tire nipples;

They make it easy to pump up even high pressure values, and the readings are accurate.

In addition, there are special pumps with a pressure gauge for inflating the front fork air shock absorbers. If necessary, they can also pump up the wheel, but this will take a lot of time and effort; they are designed for small volumes.

Marking of bicycle wheels, its interpretation

The following things are usually indicated on the tire:

• manufacturer;

• Dimensions in inches or millimeters. In this case, the larger value refers to the tire diameter, the smaller one to the width. For example, the numbers 26x2.10 mean the diameter is 26" and the width is 2.1". Dimensions in millimeters are always more accurate than in inches. 1 inch=25.4 mm;
• recommended pressure. It is indicated as a range from minimum to maximum, usually in two, sometimes in all three, units of measurement - bar, psi, kPa. For example, MIN 40 – MAX 65 PSI (2.8-4.6 BAR 280-460 kPa);
• date of manufacture.

Optimal air pressure for different types of tires and types of bicycles, seasonality. Tables

If your path runs primarily along a city road or any other dense, flat surface, it is better to maintain the pressure at a level close to the maximum permissible values. This will give riding comfort, reduce friction, and provide the bike with good roll and speed.

If you plan to drive off-road, on dirt roads, or in sand, lower the wheels so that the tire pressure approaches the minimum values. When driving, the rubber will slightly “flatten” on the surface, provide greater grip and maneuverability, and smooth out vibration.

Rider weight

The more you weigh, the more your tires should be inflated. To take into account a person’s weight when calculating the optimal pressure in bicycle tires, use the table:

When transporting any cargo, increase the pressure based on the rate of increase of 1% of the normal value per 1 kg. additional mass.

Important! Most of the rider's weight is carried by the rear wheel, and it needs to be pumped up a little more than the front wheel. It is enough to maintain a pressure difference of 10%.

The difference in temperature between the ambient air and the road surface in winter and summer seriously affects the pressure gauge readings. In hot weather, the pressure inside the bicycle tire increases, in cold weather it decreases. This should be taken into account when inflating the wheels.

Summer pressure parameters must be reduced, avoiding approaching maximum values, in order to prevent the tire from bursting. In winter, it is sometimes possible even to exceed them, this will only improve comfort and traffic safety. Inflating tires to the upper limits is especially recommended when driving in snow.

Bike type

Road bicycle wheels are inflated almost to the upper limit specified by the tire manufacturer, falling short of 0.2-0.4 atm. This difference guarantees the safety of the tire from bursting as temperature and pressure increase.

A mountain bike requires individual selection of parameters for normal air pressure in the wheels, depending on the weight of the rider and the terrain of movement. Experimentally, taking a pump with a pressure gauge with you on a trip, you need to find the pressure at which the balance between roll-up and traction will be the best.

Important! Do not exceed the maximum or decrease the minimum values ​​recommended for your tires.

Slick tires with a smooth semicircular tread surface are designed for driving on dry asphalt; they provide good rolling and speed and require pressure close to the upper permissible limit.

Semi-slick - with a smooth central part and small studs along the edges of the tread - a universal rubber for most cases. Good rolling and speed are maintained, and the ability to drive on wet road surfaces and dirt roads of varying degrees of difficulty is added. The pressure close to the maximum must be adjusted depending on the hardness of the road surface, the ambient temperature, and the weight of the person.

Cross-country tires are good for driving through forests and rough terrain. They are pumped up to an average of 3-4 atmospheres.

Bicycle tires with lugs need to be given more time to experimentally select personal pressure parameters. You need to focus on high enough values ​​to ensure the best traction on loose soils.

To choose the optimal tire pressure for your bike, you can check our tables.

Why is it necessary to monitor tire pressure, and what does improper operation lead to?

When selecting individual tire pressure parameters for your bicycle, you should take into account various nuances that may arise when the wheels are overinflated or underinflated for different types of bicycles. Let us systematize the operating features of both options.

Overpressure

• The closer the pressure is to the maximum values, the better the roll, the higher the speed, and the less effort exerted by the person. But at the same time, grip on the road surface becomes worse;
• there is a risk of breaking the inner tube against the wheel rim at the spoke mounting points;
• accelerated wear of the tread occurs.

Insufficient pressure

Even for the same bike, the correct pressure will vary under different circumstances. Gradually gaining riding experience, studying manufacturers' recommendations, checking tables of optimal values ​​from experts, you will select your own comfortable, safe for yourself and the bike, the correct pressure that will suit your riding style.

Table of permissible tire pressure for bicycles

It would seem that it could be simpler - pump it up, crush it with your fingers, and go. But no, there are some subtleties here. Tire pressure is the most important factor affecting the ride, maneuverability and control of a bicycle.

I’m deliberately not touching on tubeless tires for now, because they are installed on more expensive bikes, and this is the topic of a separate article.

Why is it important to inflate your tires to the correct pressure?

Let's start with the very basics, here's a bike driving down the road:

• The more the tires are inflated, the better the ride, the less fatigue
• The heavier the cyclist, the more you need to pump
• The more inflated the tires are, the more they shake on uneven surfaces.
• If the pressure is weak, then when driving over a curb, you can pierce the inner tube on the edge of the rim (snake bite)

And now the logical question is how to find out within what limits you need to pump, how many specific atmospheres to pump? 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 an average table for the average cyclist riding without extreme sports, on asphalt and dirt roads.

This information will be enough for you to have a comfortable ride without the tires suffering from over- or under-inflating. Well, for those who care about the details, let’s go deeper.

Road bike tire pressure

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

Let me add that the air leaks 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 is most useful.

If you inflate your road tire below the average level, you may experience an inner tube breakdown called snakebite. This happens when the wheel hits a hard object and the tire breaks through to the rim. The result is two small holes, similar to a snake bite.

Mountain bike tire pressure

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

High pressure is maintained by the semicircular profile of the tire, while maximum traction is possible when the entire contact patch area is used. 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-up will suffer and the same “snake bite” is possible.

Since basically all tube mtb tires have a permissible pressure range of approximately 2-4 atm, I would say that the working pressure lies between 2.2 and 3 atmospheres for an adult man weighing from 75 to 90 kg. It’s 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 a wider tire can be pumped with less pressure. The weight of the cyclist himself is very important, for obvious reasons.

Take a pump with a pressure gauge and try to find the lower pressure limit at which the tire will not blow out. Then try how the bike rolls at this pressure. Add air if necessary. We need to find a middle ground for both soil and asphalt.

Fat bike tire pressure

A fatbike is designed for riding on loose surfaces; its huge, high-volume tires must spread out over uneven surfaces, this is achieved with 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:

The fat rolls much better on loose snow if you pump it up at less than 5psi. But reducing the pressure below this line for tube tires can be a bad decision - the bike begins to listen poorly to the steering wheel, “float”, the nipple can break or be cut off due to the rotation of the tube. Therefore, I recommend switching to , the bike will roll better and more stable at extremely low pressure.

In addition, do not forget about this little thing that since you have much less atmosphere in your tires, temperature fluctuations will be reflected in the actual pressure. For example, at home it was 7psi, we went out into the cold of 10 degrees, it became 4.3. Here is a table from which you can calculate the approximate dependence on temperature:

Air pressure for different types of tires

If you have semi-slick, then low pressure negates its benefits. The point of a semi-slick tire is that, thanks to the semicircular profile, the tire rolls on a hard surface with the smooth part of the tread. And only when you hit soft ground does the side part of the tread come into play.

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

Standard cross country tires 2.1-2.3 inches wide require a working pressure of 3-4 atm. This type of rubber does not have very pronounced lugs; these are the most versatile tires for those who ride through forests.

Tires for more extreme riding have a width of 2.3″ or more, and traction is very important here. The pressure is calculated experimentally so that the tire does not break through during drops and hard descents.

How much to pump into tires in winter

If you ride a bike in cold weather, then you need to take into account that in the cold the pressure drops a little, so at home, pump it up about 20% higher than normal so that everything comes into balance outside.

_____________________________

Here I described it for different riding styles, I advise you to take a look.

I wouldn’t want readers to imagine a picture of a cyclist with a pump that does nothing but set different pressures for different conditions.

In fact, finding the golden mean 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 haven’t even thought about it.

In order not to lose sight of this site: - you will receive a notification about the release of a new article by email. No spam, you can unsubscribe in a couple of clicks.

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

1 atmosphere = 14.696 psi

A common mistake many novice cyclists make is over-inflation in the tires of a mountain bike or under-inflation in the wheels of a road bike.

There are factors to consider when searching for the ideal tire pressure:

Rider weight. The performance of a tire at a certain pressure depends on the weight of the cyclist. For example, a 66kg cyclist may find that 2.38psi for a 26x2.25in tire is too high and doesn't have enough grip. Conversely, a 113kg cyclist may find that their tires are underinflated, causing the tires to bend and flatten.

The table contains data on inflation of mountain bike tires with a tire width of approximately 2 inches.

Tire volume and pressure are two inextricably linked indicators. The volume of your tires determines what a certain pressure will feel like to you. For example, a 700x25mm tire inflated to 2.38 atmospheres per square inch will feel almost flat, while a 26x3.8 inch tire inflated to the same 2.38 atmospheres will feel hard to the touch - the wheel will bounce on bumps. surfaces rather than absorbing them.

A lot depends from the area. If you ride mainly on rocky roads, it is better to inflate your tires a little more to avoid flat tires and damage to the side.

So,

1.) Primer, potholes - inflate to the average value (based on the readings on the tire) or a little less.

2.) Asphalt, compacted paths - pump up to almost maximum.

Your driving style no less important than the area where you ride. The more aggressive your driving style, the more you need to inflate your tires. Do you try to choose the smoothest sections of the route, avoiding the bumps, or do you like to drive forward with unbridled energy? Do you like to keep your wheels on the surface or do you like to bounce your bike over obstacles?

Rim width plays an important role in determining the minimum possible pressure without compromising efficiency. A wide rim holds the tire better than a narrow rim. It will allow you to use lower tire pressure without sagging.

Tire design affects how it behaves at a certain pressure, approximately to the same extent as the weight of the cyclist. High TPI tires are more flexible. TPI is the number of nylon fibers per square inch of tire core. Low TPI tires have better puncture and tear resistance, but are heavier. A higher TPI value provides better traction, offering a smoother, softer ride and a lighter design. Usually, the values TPI range from 24 to 130.

Typically, tire pressure ranges from 35 to 48 psi (2.38 to 3.26 atmospheres). This pressure ensures control over the road and maximum tire grip on the surface. An overinflated tire to 50 - 60 psi (3.40 - 4.08 atmospheres) reduces riding comfort because the tire has a smaller contact patch with the road.

When riding on asphalt, an overinflated 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 break the camera by running over a stone or simply hitting an uneven road. With such a shock load, the camera is pinched between the rim and the obstacle, which can cause a “snake bite”. It will be difficult to repair a puncture of this kind. There is also a high probability of damage to the rim itself, which may lead to expensive repairs or even replacement with a new one. It is worth keeping in mind that a poorly inflated tire can be torn off on a sharp turn, and this can cause a fall. Most often, a breakdown occurs on the front wheel and is accompanied by a loud bang from the camera, as it easily bursts, having lost its protection.tires .

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

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

Road bike wheels should be inflated to 95-135 psi (6.46 - 9.18 atmospheres), since they have less air volume than mountain bikes.

In this article we will answer the question that many cyclists ask: what pressure should be in the tires of a bicycle? Let us immediately note that tire pressure is the most important factor that affects the cross-country ability and rolling ability of your bike. This is why the tire pressure must be correct.

The required pressure will help you determine the permissible values ​​​​on the tires. All products, regardless of manufacturer, must indicate the minimum and maximum permissible pressure. In rare cases, only one value is indicated - the maximum. Also, these values ​​can be indicated in different units of measurement: P.S.I. - pressure in pounds (American designation) or BAR - pressure in bars or atmospheres. In the table below, we have compared all possible values ​​to a person's weight so that you can easily determine the required pressure based on your weight.

A floor or hand pump with a pressure gauge will help you determine the tire pressure correctly. Be careful when using compressor pumps as... they supply large amounts of air at high speed, which can cause the chamber to explode.

When choosing the appropriate bicycle tire pressure, you should also pay attention to factors such as:

• The surface you are riding on. So, when driving on rough terrain, dirt or sand, it is enough to inflate the tires slightly above the minimum value, this way the grip on the road will be better. When driving on asphalt and flat surfaces, it is better to choose a value close to the maximum - this will improve the roll-up.
• The type of your bike. Depending on the type of bike you have, we recommend using different pressures. For a mountain bike this value should be lower than for example for a sports road bike. The principle here is that the narrower the tire, the higher the pressure in it should be. And vice versa.
• Temperature outside. In hot weather, it is better not to inflate the wheels to the maximum, because... the air in the chamber heats up and the pressure further increases. And in winter, even when driving on snow, the pressure should not be lower than average in order to achieve maximum tread traction.
• User weight. You should inflate your tires more if you weigh a lot or carry a heavy load on your bike.

To summarize, there are no strict rules on how many atmospheres your wheels should have. And the correct answer will be your accumulated experience!

Usually, before going out for a ride, most cyclists check the pressure in the bicycle tires with their fingers and decide whether it is enough or not. The old-fashioned method in action. If you've read this article, you understand that everyone's arm strength is different, and a well-inflated tire for one cyclist will seem deflated for another.

Therefore, it is imperative to find out what is the optimal pressure in bicycle tires in atmospheres and psi, how to inflate bicycle tires, including in winter, find out the difference in pressure for different types of bicycles, and draw up a table of tire pressures for different weights. And now about all this in logical order.

I personally cannot do something unless I have sufficient reasons for it. I think you do too. And the reasons for maintaining optimal pressure are as follows:

• The tire profile has a semicircular shape and the larger the contact patch of the tire with the surface, the greater the resistance force; At the same time, the rolling of the bicycle is significantly worsened, but its grip on the road increases.
• Based on this, we can conclude that in cases where we need excellent rolling (for example, on an asphalt road), the wheels need to be pumped to the maximum possible limit.
• When we need not only rolling, but also good grip (for example, on a dirt road), the pressure needs to be lowered somewhat, the contact area of ​​the tire with the surface will become larger, and the tire itself will seem to “lick” obstacles.
• But by lowering the wheel, we run a very high risk of puncturing it. Moreover, you can get either a regular puncture from a thorn or a “snake bite” - this is when a flat tire (most often when driving off a curb) is pushed all the way to the rim. Those. the rim hits the chamber, and 2 punctures appear in it - on the outer and inner sides of the chamber. These punctures are very unpleasant and gluing them is problematic.
• With a flat tire, there is a higher chance of damaging the rim and getting a figure eight.

What do the numbers on tires mean?

On each tire the manufacturer indicates the minimum and maximum pressure for which it is designed. When pumping, you need to focus on these numbers. The numbers are presented in different quantities - for every taste.

• BAR - used in many countries, including the post-Soviet space. 1 BAR=1 atmosphere. In the figure, the pressure should be in the range from 2.8 to 4.6 atmospheres.
• kPa - kilopascals. This value is obtained by multiplying BAR by 100. In the figure, it ranges from 280 to 460 kilopascals.
• PSI - Pressure is measured in pounds per square meter. inch. More common in the west. In this example, it is allowed to pump at 40-65 PSI.

It would be nice to have a special bicycle pump with a monometer; I wrote about their choice. Read also about choosing bicycle tires.

Mountain bike tire pressure

We have reached the climax. The pressure will greatly depend on the weight of the rider, on the width of the tire (the larger it is, the lower the pressure in it should be), on the nature of the tire tread and, accordingly, the terrain on which we will ride. And therefore there is no single recipe. You need to find your sweet spot, experiment, and understand at what pressure the maximum balance between roll and grip is achieved.

As a rule, tires indicate an operating range of 2.8-4.6 atmospheres (as in the figure above). Therefore, when inflating the wheels, you should focus on 3-4 atmospheres. This is if the wheels are 26 inches in diameter. On wheels with a diameter of 28 and 29 inches there may be different numbers, but the general logic is clear. I wrote a separate article about the diameter of bicycle wheels and how it affects the ride.

It is very important when cycling in winter, when there is snow or even ice on the roads, to choose a pressure lower than usual for a larger contact area.

• Slick tires (with a smooth tread) - used when driving on asphalt. There is no point in appearing on the ground in them, pump as hard as possible and enjoy the roll-up.
• Semi-slick tires are universal tires; they perform well both on asphalt and on dirt. We also inflate them well, and we will get a good roll on the asphalt and sufficient grip on the ground.
• Standard knobby XC tires are designed for riding on terrain where high pressure will provide the best traction.

Of course, not everyone can afford different tires and constantly change wheels, so you have to manage.

Regarding the relationship between weight and pressure, I compiled a table, but no one will ever tell the exact numbers.

Bicycle Tire Pressure Chart

Road bike tire pressure

Everything is simple here, you can pump up to the maximum limit indicated on the tire. Then there will be the best rolling, and there is no need to worry about the clutch.

But the pressure in road tires reaches 11 atmospheres, and it’s unlikely to be possible to cope with it with a regular compact pump. You need to buy a floor-mounted one, preferably with a pressure gauge, and be sure to have an adapter for the Presta nipple, which is often used on 28-inch road cameras.

That's all about the pressure in bicycle tires. Do not overstep the permissible limit, and be healthy!

You can buy a bicycle pump in Russia here.