How many atmospheres should be in a bicycle wheel. The norm of atmospheric pressure for a person
Every cyclist should check the tire pressure of their bicycle before riding their two-wheeled friend. It seems that this is not such an important value, however, a hand or foot pump may well create such a pressure that the tires will crack and burst. To prevent this from happening, find out what value your bike is rated for.
Why maintain the correct tire pressure
Tire pressure mountain bike- This is an individual parameter that is indicated on the tires. Typically, the maximum and minimum values are specified.
That is, the value can be varied and benefit from this.
Why Maintain Proper Pressure:
Poorly inflated tires can cause the chamber to break down when hitting a small obstacle.
A value within the normal range, close to the minimum, improves traction on poor roads, especially mud and rough terrain.
A value within the normal range, close to the maximum, gives an advantage in speed and allows the driver to save energy.
Too high pressure can cause a tire blowout.
The lower pressure smooths out bumps in the road and provides additional cushioning.
Knowing these factors, you can vary the amount of tire inflation to get additional benefits during a trip.
Tire markings
Pressure can be measured in three quantities:
Bar - kilogram-force per 1 cm square;
Pa - Pascals;
Psi is pounds-force per square inch.
In Russia, Bars or Atmospheres are most often used. For bicycles from the American market, the value is measured in Psi. Pascals are rarely used.
How to pump up
The best pump for your bike high pressure with manometer. So you will be sure of the choice of size and do not overdo it.
A high pressure pump is used to inflate air shock absorbers, this is a rather rare commodity. It can be found in specialized bike shops.
Such a pump has adapters for inflating tires. But this process will take more time, as it is designed for small shock absorbers. But the waiting time is worth it, because you can adjust the pressure value to the nearest Bar.
Another useful feature of this pump is the overpressure relief valve. If you missed the desired value, you can press the valve and excess air will come out.
Standard pressure from BikeHike
When inflating tires, use the values shown above. The manufacturer writes a range on the tire so that you can choose the right value for the road surface. It is considered that the maximum indicated value is for a hard asphalt road. It is better to leave the minimum value if you ride on a country road or in a forest.
If you go with minimal pressure on asphalt, you will lose speed and have to work harder with your feet. On a dirt road, additional cushioning is needed, which gives light pressure. It also improves traction, which is an added benefit.
Types of bicycles and the correct tire pressure for 26 inches: table
Exist different types tires and bicycles. For each type, recommended values \u200b\u200bare developed, which have been tested by the experience of many cyclists.
For mountain tires designed for extreme sports, you need to choose the pressure experimentally. It is individual for each cyclist.
WATCH VIDEO
Cross-country tires are universal, they are usually pumped up to 3-4 bar. They can be ridden in the countryside and on tough city roads.
Semi-slick tires are produced specifically for asphalt roads. Therefore, they must always be pumped up on maximum value. If you inflate too lightly, the contact patch with the road will increase and it will be difficult to gain high speed.
Road bike tire pressure chart:
| Tire diameter in inches | Bar | psi |
| 12 | 2,4 | 35 |
| 14 | 2,4 | 35 |
| 16 | 2,4 | 35 |
| 18 | 2,4 | 35 |
| 20 | 2,5 | 35 |
| 24 | 4,5 | 35-65 |
| 26 | 4,5 | 35-65 |
| 28 | 4,5 | 35-65 |
These are the maximum values, the most important thing is not to exceed them so that the tire does not burst. It is best to keep the tire pressure of road bikes a few tenths of a bar below the maximum.
The most comfortable pressure should be in the wheels of a bike designed for mountainous terrain. It depends on the weight of the cyclist and on the degree of roughness of the terrain. You also need to consider the width of the tires. The larger it is, the higher the pressure should be.
It is best to choose the optimal value for yourself in practice, having swept through the mountains with a pressure gauge.
The tire pressure of a 26" bike depends on the person who rides it.
Children's bicycles
For children, it is better to pump up tires to the maximum permitted value. This will make it easier to learn to ride a bike, as well-inflated tires have a smaller contact patch and require less effort for the rider.
How to check pressure after pumping
The exact value can only be checked with a manometer. Therefore, you need a pump with a pressure gauge or a separate electronic pressure gauge for bicycles. You can contact a car service to check the pressure and pump up the tires. But before you pump up the bike with a car pump, think. After all, the auto repairman may not pay attention to the pressure and ruin your tires.
WATCH VIDEO
Experienced cyclists can determine pressure by eye. You can inflate tires with a pressure gauge, memorize the value and squeeze the tire with your fingers. Remember the feeling, so you will learn to understand how inflated your wheels are.
Signs of inadequate tire pressure
Breakdown is the surest sign that you have incorrectly pumped up tires. It can burn both from too low a value (less than recommended by the manufacturer) and from too high. If you cannot visually and by touch determine the degree of inflation, measure the pressure with a pressure gauge.
WATCH VIDEO
Now you know what pressure should be in the tires of the bike. It is better to pump it up with a pump with a pressure gauge, which will help you choose the optimal value.
The degree of inflation of the wheels of bicycle equipment depends on the type of tires, bicycle, weather season, road surface features, the weight of the cyclist and his riding style. For a beginner, it is quite difficult to figure out the intricacies of adjusting the air pressure in a bicycle rubber on your own. 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 the tires of a bicycle.
Let us consider in order the main issues related to the topic of selecting an 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. In magnitude, it is almost equal to the Bar, so in practice these units are interchangeable. 1 atm. \u003d 1 kgc / 1 cm square. = 1.02 bar.
European brands often use Psi in the accompanying documentation for their bikes. 1 psi = 1 psi
When marking tires, Kilopascals can be used to indicate the minimum and maximum permitted pressures.
In practice, units of measurement are converted one into 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:
| Technical atmosphere (at or at) = kgf / cm 2 | (BAR), bar | (ATM), physical atmosphere | kPa (kPa), kiloPascal | ||
| Technical atmosphere (at or at) = kgf/cm2 | - | 0,980665 | 14,223 | 0,96784 | 98,066 |
| (BAR), bar | 1,0197 | - | 14,504 | 0,98692 | 100 |
| (PSI) Pound-force per square inch | 0,070307 | 0,068948 | - | 0,068046 | 6,894745 |
| (ATM), physical atmosphere | 1,033 | 1,01325 | 14,696 | - | 101,348 |
How to measure pressure? How to inflate bicycle tires
For lack of a better way to determine the degree of inflation of the wheels of a bicycle, you can, of course, resort to the old grandfather's method - squeeze the tire with your fingers. But since the rubber stops rolling after a couple of atmospheres, and the strength in the fingers is different for everyone, 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 be stingy and buy a good device separately.
There are basically three types of wheel inflation pumps:
Manual . With hose or integrated head. The main advantage is affordability. With an integrated head, they are more efficient, but both types give out a small amount of air, and require considerable 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 allow you to easily pump even high pressure values, the readings are accurate.
In addition, there are special pumps with a pressure gauge for inflating the air shock absorbers of the front fork. 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.
Wheel marking for a bicycle, its decoding
On the tire are usually the following things:
- manufacturer;
- dimensions in inches or millimeters. In this case, the larger value refers to the diameter of the tire, the smaller value refers to the width. For example, the numbers 26x2.10 means that the diameter is 26", the width is 2.1". Measurements in millimeters are always more accurate than in inches. 1 inch=25.4mm;
- 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 lies mainly on a city road or any other dense, even surface, it is better to keep the pressure at a level close to the maximum allowable values. This will add comfort to the ride, reduce friction, and provide the bike with a good roll and speed.
If you plan to drive off-road, primer, sand, lower the wheels so that the pressure in the rubber approaches the minimum values. When driving, the rubber will slightly “flatten out” on the surface, provide more grip and flotation, and smooth out vibration.
Rider weight
The more you weigh, the stronger the tire inflation should be. To take into account the weight of a person when calculating the optimal pressure in a bicycle tire, use the table:
In the case of transporting any cargo, increase the pressure, based on the rate of increase of 1% of the normal value per 1 kg. extra mass.
Important! Most of the load from the weight of the cyclist falls on rear wheel, and it needs to be inflated a little more than the front one. It is enough to maintain a pressure difference of 10%.
The temperature difference between the ambient air and the roadway in winter and summer seriously affects the readings of the pressure gauge. In the heat, the pressure inside the bicycle rubber increases, in the cold it decreases. This should be taken into account when inflating the wheels.
Summer pressure parameters must be reduced, avoiding approaching maximum values to prevent the tire from bursting. In winter, it is sometimes even possible to exceed them, this will only improve the comfort and safety of traffic. Especially tire inflation to the upper limits is shown when driving in snow.
Bicycle type
The wheels of a road bike are inflated almost to the upper limit indicated by the tire manufacturer, not reaching it by 0.2-0.4 atm. This difference guarantees the safety of the tire from rupture with increasing temperature and pressure.
A mountain bike requires an individual selection of the parameters of 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 coasting and traction will be the best.
Important! Do not exceed the maximum and underestimate the minimum values recommended for your tires.
Slick tires with a smooth semi-circular tread surface are designed for driving on dry asphalt, give good rolling, speed and require pressure close to the upper limit.
Semi-slick - with a smooth center section and small studs at the edges of the tread - an all-round rubber for most applications. Good rolling and speed are preserved, the ability to drive on wet road surfaces and dirt roads of varying difficulty is added. The pressure, close to the maximum, must be adjusted depending on the hardness of the road surface, ambient temperature, and the weight of the person.
Cross-country tires are good for woodland and rough terrain. They are pumped up to an average of 3-4 atmospheres.
Cycling tires with lugs must be given more time to experimentally select personal pressure parameters. You need to focus on sufficiently high values to ensure the best grip on loose soils.
You can consult our charts to find the best tire pressure for your bike.
Why it is necessary to monitor tire pressure, and what leads to improper operation
When choosing individual tire pressure parameters for your bike, you should take into account the various nuances that may occur when the wheels are over- or under-inflated to different types bicycles. We systematize the features of operation in both options.
Overpressure
- the closer the pressure is to the maximum values, the better the roll, the higher the speed, the less effort applied by the person. But at the same time, grip with the road surface becomes worse;
- there is a risk of punching the chamber from the inside against the wheel rim at the places where the spokes are attached;
- accelerated tread wear occurs.
Insufficient pressure
Even for the same bike, the correct pressure will vary under different circumstances. Gradually gaining riding experience, studying the recommendations of manufacturers, referring to the tables of optimal values \u200b\u200bfrom experts, you will choose your own comfortable, safe for yourself and the bike, the right pressure that will suit your style of movement.
Table of permissible tire pressures for bicycles
| Model | Modifications | Recommended Tire Size | Recommended tire pressure | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| no load in summer | Loaded in summer | No load in winter | Loaded in winter | |||||||
| Front | rear | Front | rear | Front | rear | Front | rear | |||
| all (all) | all (all) | 12 inches x2.125 | 2.4 | 2.4 | 2.4 | 2.4 | 2.3 | 2.3 | 2.3 | 2.3 |
| all (all) | all (all) | 14 inches x2.125 | 2.4 | 2.4 | 2.4 | 2.4 | 2.3 | 2.3 | 2.3 | 2.3 |
| all (all) | all (all) | 16 inches x2.125 | 2.4 | 2.4 | 2.4 | 2.4 | 2.3 | 2.3 | 2.3 | 2.3 |
| all (all) | all (all) | 18 inches x2.125 | 2.4 | 2.4 | 2.4 | 2.4 | 2.3 | 2.3 | 2.3 | 2.3 |
| all (all) | all (all) | 20 inches x2.125 | 2.4 | 2.4 | 2.4 | 2.4 | 2.3 | 2.3 | 2.3 | 2.3 |
| all (all) | all (all) | 24 inches x2.125 | 3.5 | 3.5 | 3.5 | 3.5 | 3.4 | 3.4 | 3.4 | 3.4 |
| all (all) | all (all) | 26 inches x2.35 | 3.5 | 3.5 | 3.5 | 3.5 | 3.4 | 3.4 | 3.4 | 3.4 |
| all (all) | all (all) | 26 inches x2.125 | 3.5 | 3.5 | 3.5 | 3.5 | 3.4 | 3.4 | 3.4 | 3.4 |
| all (all) | all (all) | 28 inches x2.125 | 3.5 | 3.5 | 3.5 | 3.5 | 3.4 | 3.4 | 3.4 | 3.4 |
| all (all) | all (all) | 29 inches x2.10 | 3.6 | 3.6 | 3.6 | 3.6 | 3.5 | 3.5 | 3.5 | 3.5 |
November 15th, 2015 Admin
After buying new tires for a car, during its installation, the question often arises: to what pressure should the wheel be pumped up? This information can be found on a sticker on the fuel filler flap, on the B-pillar on the driver's side, or even on the glove box lid (on the back). In addition, it must be indicated on the sidewall of the tire. However, it happens that all these numbers and designations confuse the motorist even more, and therefore, today we will examine this issue in detail, at the same time paying attention to a number of non-obvious nuances.
Optimal pressure
Usually, the unit of pressure is the technical atmosphere (at) or kilopascal (kPa). Here is an example of what it should look like:
- Tire size - 185 /65 R15;
- Pressure (respectively for the front and rear axles) - 220 And 220 kPa;
- Pressure in case of heavy axle loads – 230 And 270 kPa respectively.
Sometimes, instead of designating pressure units, they will be in Russian (see above).
In some cases, "For Cold Tires Only" will be read on the sidewall of the tire. Below we will analyze in detail everything related to units of measurement and this inscription.
Vehicle tire pressure units
First, let's clarify the situation with units of measurement. You may well encounter the fact that the scale of your pressure gauge is marked in atmospheres, and the tire manufacturer indicates the pressure in kilopascals. Thus, in order to correctly inflate the wheels, you will have to find a way to convert the values.
You can just remember the following: 1 bar = 1.02 at = 100 kPa, and 1 at = 101.3 kPa = 0.98 bar.
However, if you do not need to train your memory, just keep a mobile phone at hand, since almost every one of them is equipped with a converter.
If your vehicle is from the UK or US, you may encounter psi (pounds per square inch). 1psi = 0.07 at.
The clarification about loading from the example above is not accidental: when the car is fully loaded, the wheels should be pumped up more than usual.
A little nuance: all these values \u200b\u200bimply driving on asphalt, and therefore if you find yourself on the road, the pressure should be reduced by 10% . This will allow the rubber to become softer, which will facilitate the work of the suspension and reduce the risk of breakage.
When to measure tire pressure: cold / hot
Now let's deal with the inscription "cold tires only". This means that the pressure measurement must be carried out at normal tire temperature.
In summer, it is advisable to measure the pressure in the wheels in the morning, strictly before the trip. Why exactly? When driving, due to friction, the tires heat up, and the temperature of the air inside the tires rises, which provokes the expansion of gases and an increase in pressure, i.e. measurement results will be incorrect.
In the cold season, everything is exactly the opposite - during parking, the pressure drops, so measurements are taken either in a heated garage at a positive air temperature, or after a short drive in normal mode.
Tire pressure table by car brand
Lowered tires - pros and cons
Some car owners reduce tire pressure somewhat in winter in order to increase the contact patch and, accordingly, traction. In general, they are right - the car behaves more stable. However, there are still more disadvantages, because tire wear increases greatly, the braking distance becomes longer, and the car's handling deteriorates.
However, in some situations it is necessary to reduce tire pressure. For example, when driving off-road (loose snow, swampy soil or sand), as this helps the car not get stuck. That is why many four-wheel drive trucks are equipped with a centralized tire inflation system.
But the above is a special case that confirms the rule. If you do not move off the asphalt, it is better not to lower the tires by more than 10%. Also, do not forget that you should not pump over the wheels, since the behavior of the car will change dramatically for the worse, and the tire may burst, and this threatens an accident. In general, it is better to observe the recommended "golden mean". That's all, good luck on the road!
Approximately one third of the population of our planet reacts sensitively to changes in the environment. Most of all, human well-being is affected by atmospheric pressure - the attraction of air masses to the Earth. What atmospheric pressure is considered normal for a person depends on the area in which he stays most of the time. Everyone will feel comfortable in the conditions familiar to him.
What is atmospheric pressure
The planet is surrounded by an air mass, which, under the influence of gravity, presses on any object, including human body. The force is called atmospheric pressure. A column of air weighing approximately 100,000 kg presses on each square meter. Atmospheric pressure is measured with a special device - a barometer. It is measured in pascals, millimeters of mercury, millibars, hectopascals, atmospheres.
The normal atmospheric pressure is 760 mm Hg. Art., or 101 325 Pa. The discovery of the phenomenon belongs to the famous physicist Blaise Pascal. The scientist formulated the law: at the same distance from the center of the earth (does not matter, in the air, at the bottom of the reservoir), the absolute pressure will be the same. He was the first to propose measuring heights by barometric equalization.
Atmospheric pressure norms by region
It is impossible to find out what atmospheric pressure is considered normal for a healthy person - there is no definite answer. The impact varies across regions of the world. Within a relatively small area, this value can vary markedly. For example, in Central Asia, slightly elevated figures are considered standard (average 715-730 mm Hg). For central Russia, normal atmospheric pressure is 730-770 mm Hg. Art.
The indicators are related to the elevation of the surface above sea level, wind direction, humidity and ambient temperature. Warm air weighs less than cold air. Over an area with elevated temperature or humidity, the compression of the atmosphere is always less. People living in high mountain areas are not sensitive to such barometer readings. Their body was formed in these conditions, and all organs underwent appropriate adaptation.
How pressure affects people
The ideal value is 760 mm Hg. Art. What awaits when the mercury column fluctuates:
- A change in optimal performance (up to 10 mm/h) already leads to a deterioration in well-being.
- With a sharp increase, decrease (on average by 1 mm / h), even in healthy people, there is a significant deterioration in well-being. Appears headache, nausea, loss of working capacity.
Meteorological dependence
Human sensitivity to weather conditions - wind changes, geomagnetic storms - is called meteorological dependence. The influence of atmospheric pressure on is not yet fully understood. It is known that when weather conditions change, internal tension is created inside the vessels and cavities of the body. Meteorological dependence can be expressed:
- irritability;
- pains of various localization;
- exacerbation of chronic diseases;
- general deterioration of well-being;
- vascular problems.
In most cases, weather dependence affects people with the following diseases:
- respiratory diseases;
- hypo- and hypertension.
Response to high blood pressure
A decrease in the barometer by at least 10 units (770 mm Hg and below) has a negative impact on health. Particularly affected by weather changes are people with long-standing diseases of the cardiovascular and digestive system. Doctors on such days recommend reducing physical exercise, less to be on the street, do not abuse junk food and alcohol. Among the main reactions:
- feeling of congestion in the ear canals;
- decrease in the number of leukocytes in the blood;
- decreased activity of intestinal motility;
- violation of the functionality of the cardiovascular system;
- poor ability to concentrate.
How much to pump up the wheels? Many cyclists often ask this question. 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).
1 atmosphere = 14.696 psi
A common mistake many beginner cyclists make is over-inflating mountain bike tires or under-inflating road bike tires.
There are factors to pay attention to when looking for the ideal tire pressure:
Rider weight. The performance of a tire at a given pressure depends on the rider's weight. For example, a 66 kg rider may find that 2.38 psi for a 26x2.25 inch tire is too high and grip is not good enough. Conversely, a 113kg cyclist may find that their tires are under-inflated, causing the tires to bend and deflate.
The table shows inflation data for mountain bike tires with a tire width of approximately 2 inches.
| Weight cyclist (kg) | Pressure (psi) | Pressure (atmosphere) |
| 50 | 35-38 | 2,38-2,59 |
| 63 | 37-40 |
2,52-2,72 |
| 77 | 40-43 | 2,72-2,93 |
| 91 | 42-45 | 2,86-3,06 |
| 105 | 45-48 | 3,06-3,27 |
| 118 | 47-50 | 3,2-3,4 |
Tire volume and pressure are two inextricably linked indicators. Tire volume determines how a certain pressure will feel to you. For example, 700x25 mm tires inflated to 2.38 atmospheres per square inch will be practically flat, while a 26x3.8 inch tire inflated to the same 2.38 atmospheres will feel hard - the wheel will bounce on bumps. surfaces rather than absorb them.
Much depends from the terrain. If you ride primarily on rocky trails, it's best to inflate the tires a little more to avoid flattening and damage to the sidewall.
So,
1.) Primer, potholes - inflate to the average value (guided by the indications on the tire) or a little less.
2.) Asphalt, rolled paths - inflate almost to the maximum.
Your driving style no less important than the area where you drive. The more aggressive the driving style, the more you need to inflate the wheels. Do you try to take the flattest sections of the track, around the bumps, or do you like to go forward with unbridled energy? Do you like to keep your wheels off the ground, or do you enjoy bouncing your bike over obstacles?
Rim width plays an important role in determining the possible minimum pressure without sacrificing efficiency. A wide rim holds the tire better than a narrow rim. It will allow you to use lower tire pressures without sagging.
Tire construction affects how it behaves at a certain pressure, about the same as the weight of the cyclist. High TPI tires are more flexible. TPI is the amount of nylon fibers per square inch of a tire base. Low TPI tires have better puncture and tear resistance but are heavier. A higher TPI value provides better traction, offering a smoother and softer ride, as well as a lightweight construction. Usually, values TPI range from 24 to 130.
Typically, tire pressure is in the range of 35 to 48 psi (2.38 to 3.26 atmospheres). With this pressure, control over the road and maximum tire grip are ensured. An over-inflated 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 over-inflated mountain bike tire wears out very quickly.
An under-inflated tire 28 - 32 psi (1.9 - 2.17 atmospheres) is also fraught with danger. Because of this, you can easily break through the camera by running into a stone or simply hitting the roughness of the track. Under such an impact 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, this can lead to its expensive repair or even replacement with a new one. It should be borne in mind that a poorly inflated tire on a steep turn can be “teared off”, and this can cause a fall. Most often, a breakdown occurs on the front wheel and is accompanied by a loud pop of the camera, as it easily bursts, having lost protection.tires .
Attention! Do not exceed the pressure indicated by the manufacturer on the tire sidewall!
On surfaces like snow and sand, inflated wheels will obey better.
In extreme heat, driving at high speeds, it is better not to inflate the tires to the maximum, as the wheels may overheat.
In winter, you need to pump up the wheels more strongly, otherwise the tires and the chamber may be damaged from the cold.
wheels road bikes should be inflated to 95-135 psi (6.46 - 9.18 atmospheres), since the air volume in them is less than in the mountains.
