Bicycle tire pressure: what should be and how to swing?
The quality of cycling depends on the inflation pressure of the tire. Insufficient compressed air pressure in the wheels leads to more frequent punctures and breakdowns in the chamber and tire. Excessive. to rubber abrasion. The optimal tire pressure can be determined based on your experience with proper cycling and manufacturer recommendations.
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 none at all. 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 set 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 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 matches the specified value, and the wheel feels elastic and firm, 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 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 rubber by the cord and the bead cable.
If the pressure is too low, the bicycle tire will sink under the weight of the cyclist. It clogs 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.
What and how is 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 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 pressure value 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 should be?
Pressure standards are different for each type of tire.
For road bikes
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 load 9 and drive safely 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 become loose 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 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 develops).
A road bike with 10 bars in wheels, traveling 40 kilometers per hour and carrying a biker weighing 80-90 kg, undergoes the same. During the week, the working pressure in the wheels drops by about 1.5 atmospheres. After feeling the wheel after a 300 km marathon, you are unlikely to feel that it has lowered, but the pump pressure gauge (or car compressor) will immediately indicate this.
It inflates a bicycle wheel in a few seconds, and when the set pressure is reached, the automatics turn 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 his 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.
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 is capable of withstanding tire pressure up to 5 atmospheres. Exceeding this value will damage the rim on the first bump or blow up the camera after acceleration over 30 km / h, sharp braking. A wider rim holds the tube better than a narrower one. 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, 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.
Fatbikes are best for riding on sand, snow and rocky roads. An example is winter movement on a road that is close to a railway embankment and is covered with a 10 cm layer of snow. The running zone of a fat bike tire is 2-3 times wider than that of rubber for a mountain bike or city bike. The large contact area of the tire with the road brings the fat bike closer to the wheels of the motorcycle. On a fat bike, you can freely ride on the off-road forests and fields. The PSI chart is based on a rider with an average weight of 80 kg.
BIKE TIRE PRESSURE WHAT SHOULD BE AND WHAT TO RUN?
Every bicycle lover is obliged to monitor the condition of his two-wheeled horse. It is from this that its service life and ride comfort will envy. When you go on your next trip, do not forget to measure your tire pressure. This procedure is mandatory, because the comfort while driving directly depends on it.
Oddly enough, first of all the quality of cycling, especially on asphalt, depends on the pressure in the wheels of the bike. Under-inflated wheels easily break through and dampen a large percentage of the cyclist’s efforts, while over-inflated wheels can damage the camera and lead to its rapid wear. Accurate knowledge and experience will help you find the middle ground.
Many are accustomed to checking tire pressure using the old-fashioned method with their fingers. However, this method is very imprecise, and the concept of “well-inflated wheel” can be very different for every cyclist. That is why it is best to always have a pressure gauge on hand to accurately determine the tire pressure.
Its cost is quite low, so everyone can afford such an acquisition.
In fact, the optimal pressure in the tires 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:
- 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.
If the wheels are over-inflated, the bike will roll well, but the tire will not absorb at all on uneven surfaces. All difficult sections will be much harder, since the contact patch of the tire with the ground will have a minimum area, and you will be skidded around the bends. Needless to say, when cycling in winter, the situation is aggravated by the slippery surface. In addition, pumping can cause the wheel to explode. Old Soviet cameras are especially susceptible to this, the material of which is already turning into dust from old age. The tire does not break due to excess pressure immediately, but for example on a hill where a pebble falls under the wheel. This situation is dangerous because sometimes literally rips the tire off the wheel.
The air pressure in the tires of the bicycle also affects the “piercing” of the wheel. Pumped rubber easily picks up all the carnations and glass on the road.
If the tires are flat, the situation is no better than with inflated wheels. The tire does not sit tightly on the rim, it can jump off the wheel, and when driving onto the curb, a puncture (the so-called snake bite) can form. The roll of the bike decreases and more and more forces are required to pedal. However, when choosing between an under-inflated tire and an under-inflated tire, it is better to opt for an under-inflated tire. But we must not forget about reasonable limits. If the tire drags like a rag, then you are clearly mistaken with the pressure.
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 be information about the permissible pressure range in the chamber.
Why is this information not shown on the camera itself? Because the only point in it that is 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.
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.
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”.
Data from a smart pressure sensor on a smartphone screen
Bars are also obsolete units of measurement, but they are actively supported in 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.
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 characters 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 as 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.
Manufacturers indicate the recommended parameters on the side of the tire. Usually they are in the range 35. 60 psi (2.38. 4.08 atmospheres). But still, this is a parameter that is selected purely individually. Therefore, there are a number of recommendations that are considered common to all people.
- The high pressure increases the “roll”. the cyclist saves energy, and the rolling speed increases.
- Excessive, as well as too little pressure in the wheels (both in the front and in the rear) of the bicycle can cause the rim to burst the chamber from the inside.
- Low pressure prevents vehicle mechanisms from breakage when driving through holes, and also provides better “grip” with the surface when traveling over rough terrain.
How riding style and tire pressure depend.
When a cyclist trains on relatively flat asphalt roads, country and forest dirt roads and paths. For this style of riding, I prefer to pump the wheels up to 3.5-4 atmospheres. Such a high bar value allows you to achieve good speed characteristics, high rolling, but when it hits bumps and stones, the fifth point immediately feels all the unevenness of the road surface.
For those who like walking at low speed on the flat roads of parks, 2.5-3 atmospheres is enough. On the Internet, you can often find recommendations to pump 2-2.5 bar into wheels, this is justified only for tires at least 2 inches wide and subject to driving over rough terrain or poor coverage. Low pressure increases traction and comfort, but reduces roll on flat pavement. You should not drive at a pressure less than 2 atmospheres under any circumstances.
The choice of the terrain, on which you prefer to ride, obliges you to choose a certain type of tire, but in general, if you have a universal tread, you can make your ride comfortable on a particular type of road surface by changing the amount of atmosphere on the wheels. The figures below are based on a standard 2-2.1 ″ tire.
For gravel, mud, grass, sandy surfaces, it is better to pump up to 2.5 atmospheres, which increases the adhesion of the tread to the ground and allows the wheel to smooth out all the irregularities of the road surface well enough.
For flat asphalt roads, feel free to use a pressure of 3 bar or more. However, there is one but. If you have a fairly bald tread (wheels with a weak relief or slick tires), and you are driving at high speed on wet or even wet asphalt, then you risk slipping (flying out) at a turn. If it rains on the road, just slow down or slightly deflate the tires.
This article describes the most acceptable criteria for choosing tire pressure, but since each person independently selects the most convenient pressure values, I advise, first of all, when mastering a bicycle, experiment.
How to pump
Bicycle luggage requires maintenance and inflation 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 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 own professional tool can play a bad joke in the event of an unexpected situation or when you deviate from the standard route.
Here are some tables that will help you navigate in difficult situations, namely:
- an unknown tire without markings was purchased;
- no physical access to the bike;
- the marking is incomprehensible, the numbers are marked in unknown units.
Mountain bike table:
For a road bike, the pressure should be much higher, and typically range between 6.5. 9 atmospheres (up to 130 Psi), up to the maximum indicated by the manufacturer.
For children, it is better to inflate the tires to the maximum allowed value. This will make it easier to learn to ride a bike, as well-inflated wheels have a smaller contact patch and the driver has to put in less effort.
Seasonal adjustments are quite serious, mainly related to mountain bikes. In summer, you should slightly underestimate the pumping and not rest on the maximum. Hot asphalt heats up the air inside the chamber, which increases the volume and therefore the pressure. Also, a pumped tire wears out very quickly.
In winter, you should sometimes slightly exceed the maximum in order to achieve maximum work from the tread, especially if the rubber is selected with spikes.
For heavy riders or heavily loaded bikes, it is very important to add pressure, because a lot of mass will squeeze the wheel of the bike and problems with insufficiently inflated cameras can come out much earlier.
Recommended pressure for weight addition is 1% for every kilogram of rider weight over 50.
Approximate values by type of rubber
Optimizing the inflation rate of a bicycle tire depends on the type of tire used, and in particular mainly on the type of tire. If the bike is “shod” in slick or semi-slick rubber, then minimizing pressure is permissible only on hot days. As shown by bench tests of slick (low-relief) tires, a decrease in the level by 25.0% to the optimal level nullifies all their advantages.
You can also give recommendations for inflating wheels with different tires.
If the bike is “shod” in tires 2.0… 2.3 inches wide with cross-country protectors, then the optimal pressure range is 3.0… 4.0 atmospheres (bar). A decrease in this value will require an increase in the consumption of muscle energy, and exceeding the level of inflation of bicycle tires above the upper limit, when driving off-road, often leads to an explosive destruction of the tire.
Extreme tires (Downhill / Slalom 24 “x 2.10” or “Kenda K905 20 x 1.95”) with complex tread, are best inflated to the average recommended pressure. This will provide the necessary adhesion to the supporting surface. In the future, its indicator can be adjusted for specific driving conditions.
BMX stunt models should be inflated medium, between high and low to have sufficient grip, and then subtly varied for each stunt.
For winter skiing, it is worth choosing a pressure slightly above normal, since at sub-zero temperatures the air in the tire becomes denser and takes up less space.
How to check the pressure after inflation
The value can only be checked exactly with a pressure gauge. Therefore, you need a pump with a pressure gauge or a separate electronic bicycle pressure gauge. You can go to a car service to check the pressure and pump up the wheels. But before pumping up your bike with a car pump, think about it. After all, the auto repairman may not pay attention to the pressure and ruin your tires.
Experienced cyclists can measure pressure by eye. You can inflate tires with a pressure gauge, memorize the value and squeeze the tire with your fingers. Memorize the feeling so you learn to understand how inflated your wheels are.
Despite the recommendations of the manufacturers, such a parameter as the pressure in the wheel chamber is a matter of personal preference. Each cyclist adjusts this parameter for himself, for the track on which he is going to ride, for his personal riding style and level of technical training. Therefore, how much should be pumped up, everyone decides for himself. Every experienced rider knows a number of factors and operates with them:
- The rider approaches the parameters to the maximum if he wants to add speed to the bike while riding and at the same time save his strength.
- The cyclist approaches the minimum value to provide better traction.
- Low inflatedness helps smooth out minor road bumps while driving.
- Over-inflated tires will lead to tube breakdown on the rim.
- Under-inflated tires will also cause tube damage from “snake bites”.
The pressure in a bicycle tire is a very important parameter, it should be understood what restrictions are imposed by tire manufacturers and what riding style of a particular rider can be improved with just a couple of strokes of the pump handle. In any case, how many atmospheres to pump at each moment is a unique decision, and it is taken, rather, based on accumulated experience than according to strict rules.
Video. Question answer
Weighing 50 kg (110 lbs). 2.4-2.6 atmospheres (35-38 psi) Weighing 63 kg (140 lbs). 2.5-2.7 atmospheres (37-40 psi) Weighing 77 kg (170 lb). 2.7-2.9 atmospheres (40-43 psi) Weighing 91 kg (200 lbs). 2.8-3 atmospheres (42-45 psi) Weighing 105 kg (230 lbs). 3.3.3 atmospheres (45-48 psi) Weighing 118 kg (260 lbs). 3.2-3.4 atmospheres (47-50 psi)
In expensive, quality road bike tires measuring 21-23mm, the pressure should be 10-11 atmospheres. In wider or lower quality pressures lower, the maximum value is always indicated on the sidewall. It cannot be exceeded, it is advisable to maintain it before each ride.
10 psi. Rolled snow, paths 8 psi. Heavy snow 6 psi and below. Loose snow 5 psi. Killed asphalt, soil and rubble
1 psi = 0.068 atm 1 atm = 14.696 psi1 atm = 101.348 kPa1 bar = 0.98 atm1 bar = 0.98 atm
Bicycle tire pressure must be at least 2.4 atmospheres and not more than 4.1 atmospheres
It is best to observe the rear tires in full weight conditions. It should deform noticeably, but not to the extreme. Deflection should be approximately 10-20% of the tire height from the ground to the rim edge. less deflection for road conditions, more off-road.
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How much pressure to swing the wheels of a bicycle
Many cyclists do not often think about how to properly inflate the wheels and how much pressure should be maintained in the bicycle tires. Keeping track of the technical condition of a two-wheeled friend is quite a routine exercise, so checking the pressure in bicycle tires is often carried out visually, at best by touch.
What you need to know about bicycle wheels
In order to accurately measure whether the wheels are sufficiently inflated, you must have a pressure gauge with you, a special device for measuring the number of atmospheres in the tires. However, the optimum pressure can vary depending on the type of tire and its manufacturer.
A bicycle tire consists of a tube and a tire. The tire is responsible for the limiting pressure values. Regardless of the chamber, the optimal pressure to be maintained in the tires depends on the values indicated on the tire.
How much pressure is needed to inflate the bicycle wheels
All modern tires have the maximum and minimum pressure values indicated. There are two units of measurement. atmospheric pressure, measured in Bar (BAR) and pound-force per square inch (PSI). Pressure gauges usually indicate pressure in Bars, if the tires indicate pressure in lbf only, you can convert them to Bars. 1 Bar ≈ 15 PSI.
The permissible pressure range for bicycle tires is usually within a couple of atmospheres. This margin allows you to vary the pressure, depending on the surface you plan to ride on and your weight.
When driving on level, decent asphalt, or other hard surfaces, keep the pressure close to the upper permissible limit. If, while riding a bicycle, you pay attention to the rear wheel, you will notice that the tire is squashed under your weight, due to which the contact surface with the asphalt increases, friction increases, and significantly more effort will have to be applied to create driving force.
However, the worse the surface, the less comfortable it will be to ride on poor surfaces.
For a beginner who does not know the features of local reliefs, all of the above can be taken into account and use the universal table. You need to pump up to the number of atmospheres corresponding to your weight, and you can already feel confident on the road.
How to find out the pressure in the wheels of a bicycle
The best way to find out how much tire pressure is is to use a pressure gauge. In this case, it will be most convenient to acquire a pump with a built-in pressure gauge. With such a pump, the required pressure can be set the first time. Having such a pump with you, you can quickly change the pressure along the route, depending on the surface, the most favorable for its passage.
Without a pressure gauge, it is also possible to inflate the wheels with sufficient accuracy. To do this, you need to determine the number of pump strokes until a certain pressure level is reached. In this case, the pressure gauge is only needed once. The wheel is completely lowered, then inflated, the number of strokes is counted, the pressure is measured, as a result, we get the value by which the pressure increases for one stroke.
Now, even in the absence of a pressure gauge, you can easily inflate the wheel to the desired pressure. However, remember that measurements must be taken for each pump individually.
How often to check the pressure at the bicycle wheels
How often to inflate the wheels of a bicycle is an individual question, and depends on the type of bicycle, its age, riding style, surfaces on which it is used. If the bike is new, mountain, routes within the city, on decent asphalt, without elements of extreme, the pressure can be checked no more than once a month.
On average, the recommendations are as follows. for a mountain bike it will not be superfluous to check the pressure once every couple of weeks, for a road bike it is better to do this every day. In the event of a puncture, the low pressure can be observed visually, and it will be quite difficult to ride such a bike.
With the experience of riding, the feeling of the bike comes, and how much the pressure in the tires of the bike corresponds to the norm will be clear almost immediately. Reduced pressure is characterized, first of all, by too soft a ride, bumps are well swallowed and when driving, even on not too good roads, bumps are practically not felt, while maintaining the speed is much more effort.
Why it’s important to inflate your tires with the correct pressure
Let’s start with the very basics, here’s a bike riding the road:
And now a logical question. how to find out within what framework you need to pump, how many 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 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.
Road Bike Tire Pressure
With bikes for paved 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.
Mountain Bike Tire
Off-road bikes are a little more complicated. The point is that 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 entire contact patch is engaged. In other words, the more the tire “flattens”, the better for cross-country ability and handling. 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 male 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.
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|
|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, “float”, 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 10 degrees, it became 4.3. Here is a table for you, according to which you can calculate the approximate dependence on temperature:
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What pressure should be in bicycle tires
Typically, pressure limits are indicated on the side of the tire. For example, min 2.4 Bar (32 PSI). max 4.1 Bar (56 PSI). These numbers mean that the tire pressure should be at least 2.4 atmospheres and not more than 4.1 atmospheres. The difference between the minimum and maximum value is almost two atmospheres and how to choose the right one, in this case, the pressure?
This breakdown depends on the road on which you will be driving:
- When driving on an asphalt road, the tire pressure should approach the maximum value indicated on it;
- When driving on a dirt road, the pressure should be kept slightly above the minimum value or average.
This is explained by the fact that when riding on asphalt, the friction of poorly inflated tires increases, and the speed of the cyclist is lost. When driving on a dirt road, the contact should be maximum and therefore the tire pressure should be slightly above the minimum value. In addition, a slight pressure softens driving on bumps and off-road.
Air pressure for different types of tires
If you have semi-slick tires on your bike, then they should be inflated closer to the maximum value. This type of tire is designed for both asphalt and off-road driving. When you drive on asphalt, only the middle part of the semi-circular tire is involved in hitching to the surface.
And when leaving on a country road, the lateral parts of the tread come into operation and the adhesion to the road increases. With a weak tire inflation, it will be difficult for you to drive on the asphalt, since the side tread will slow down the movement. Therefore, it is worth pumping closer to the max pressure.
Conventional cross country tires pump up to 3-4 atmospheres. These all-rounders are good for both off-road driving and quiet driving on good roads.
Road bike tire pressures. Table.
|Tire size, inches (in)||PSI, lbf / sq. inch||BAR / bar|
Mountain bike tire pressures. Table.
The tire pressure of mountain bikes is adjusted according to the weight of the cyclist and the terrain you will be riding. The main indicator is the width of the tire, the wider the higher the pressure. It is rather difficult to bring certain values \ u200b \ u200b, you need to try to find the golden mean yourself, in which the ride will be comfortable and fast.
|Cyclist body weight, kg||Pressure, atmospheres (at)|
High pressure pump for bike and bicycle forks
You have decided on the numbers and approximately understood how much pressure should be in the tires. It remains to find a pump with a pressure gauge. The product is quite specific and is used more by those people who have an air shock absorber on their bike.
You cannot pump the shock absorber with an ordinary pump, therefore a high pressure pump is used. This pump also has adapters for inflating bicycle wheels. True, you have to work hard, because it’s one thing to pump up a small shock absorber, and quite another to pump up a bicycle wheel. But there are pluses, you will clearly record the required tire pressure on the pressure gauge.
Why the pressure has to be right?
It should be noted that tire pressure is still an individual parameter. But there are also factors to consider when inflating bicycle tires:
- Pressure close to the maximum value. gives the bike speed and saves energy;
- Pressure close to the minimum value. improves grip, especially off-road;
- High pressure. can lead to breakdown of the chamber from the side of the rim;
- Low pressure. can also lead to breakdown of the chamber when hitting an obstacle violently;
- Low tire pressure smoothes out numerous bumps in the road.
How is blood pressure measured??
It is customary to denote pressure in three units of measurement:
Psi. Pound Force Per Square Inch,
Bar. equates to measurement in “atmospheres”, kilogram-force per square centimeter,
In the case when the manufacturer trades with the American market, tires are marked with the designation Psi.
and other European countries use the Bar label because measurement equates to “atmosphere”.
Rarely used in bicycle designation Pa (Pascals).
The ratio of these units is as follows: 1 Bar = 1,000,000 Pa = 14,504 Psi.
What do the numbers on the tire mean??
If you find 2.5-4.1 on the tires it means pressure in Bar or “atmospheres”. If 90-140 is clearly Psi. But if the numbers are three-digit and next to them there is a number k, for example 280-360 kPa, then this is Pascal. Typically, the values are duplicated in at least two dimensions, and the responsible manufacturer applies the data in all three dimensions.
What pressure to choose?
For everyday riding, choose a medium tire pressure on your bike, because riding involves riding both a good road and a dirt road. For driving on snow or sand, tires should be inflated just above the minimum value.
Hitching with a loose road surface will be maximal and cross-country ability will increase. When driving on a well-rolled road, inflate the tires closer to the maximum value. The bike speed will increase significantly. If you don’t have a pressure gauge at hand, you can drive to a gas station and check the pressure for free. And if necessary, you can pump up the wheels.
With regard to the season, tire pressure varies dramatically. In winter, you can even exceed the maximum tire pressure and achieve excellent tread performance. In the summertime, you should not inflate tires to the max value.
Increased air temperature, friction against asphalt can increase the already high pressure in the chamber. This can ultimately damage the tube and tire. In addition, a heavily inflated tire wears out faster.
Heavy cyclists should pay particular attention to wheel pressure. A large mass compresses the wheel and when driving over an obstacle, you can damage tires and rims. Above was a table of the ratio of human weight and pressure in the bicycle wheels.
Tire care and repair to drive longer
Bicycle tires last a long time. Over time, the tire wears out due to tread wear. For tires to last a long time, you need to properly operate and store them. With a reduced pressure in the tire, destruction occurs, small cracks appear, the bending of the sidewall is deformed.
All this leads to faster tire wear. Uneven tread wear is affected by harsh braking. And it is also possible to shift along the rim during braking and rupture of the chamber in the area of the nipple. To avoid this, try to brake smoothly without sudden stops.
Why maintain the correct wheel pressure?
There are several reasons to maintain the correct tire pressure:
- If you want to go fast, increase the tire pressure;
- If you need good grip. set the tire pressure slightly above the minimum value;
- When the wheels are flat, there is a high probability of tire and tire damage;
- Never raise the pressure above the maximum allowable.
Tips for tire care
- Choose the right pressure for your riding type.
- Avoid hitting sharp objects, glass, spikes.
- Inspect the tread and remove stuck stones, glass, etc.
- Cover the tires with a thin layer of glycerin and release the pressure to the minimum value before putting the bike to the “winter parking”.
Drawing conclusions, we can say that the wheels should be inflated so that they can hold the road well and not lead to damage to the camera. For different types of bicycles, the pressure in the wheels is also different, but it is better to inflate the wheel more than ride on half-deflated slopes. The maximum value is quite difficult to approach, and the ride is not particularly comfortable. With half-flat wheels, there is every chance to puncture the wheel, and even worse, damage the rim.
By listening to these tips, you will significantly increase the “life” of your tires and tires, and they will last you more than one year.
How much pressure should a mountain bike tire have? How much to pump other bicycles? How often should the tire pressure be checked? We will answer these and other questions regarding the pressure in the bicycle tires in this article.
There is a well-known old-fashioned way of checking the pressure in the wheels of a bicycle. to try to squeeze the wheel with your hand. If it didn’t work out, then the pressure is in theory normal. But there are people who are capable of chopping nuts with their hands, and especially outstanding ones can crush a stone with their fingers. And someone crumples a candy wrapper not without difficulty. It is clear that the method is very imprecise.
Why the pressure has to be right?
The first thing to mention is that the pressure you need will be different for different types of bikes. Do not be afraid to pump the wheel, the upper limit is usually quite high and very few people will find it comfortable. It is worse to drive under-pumped. you can easily puncture or puncture a wheel. And you will need to repair or replace the bike camera.
And this is not all that a half-flat tire threatens. Wheels, due to insufficient tire pressure, damp worse. And bumps on bumps in the road can damage the rim and form eights on the wheel.
What do the numbers on the tire mean??
From the above, it becomes clear that the tire pressure of a bicycle should not be ignored. over, choosing the pressure is not at all difficult. You just need to look at the sidewall of the tire and find there the maximum and minimum pressure values for your tire. How it looks approximately, see the picture below. BAR is the pressure in bars or atmospheres (a common unit of pressure measurement), as you can see in the picture for a given tire, the value should be in the range from 2.8 (minimum) to 4.6 (maximum). If this value is multiplied by 100, the pressure in kilopascals is obtained. 280 and 460, respectively. PSI is the pressure in pounds per square inch, the minimum for the tire in the picture is 40, the maximum is 65.
What pressure should be in tires?
The tire pressure of the car should be checked at least once a week. Modern tubeless tires are very sensitive to pressure, so a decrease or increase in a tire by only 15-20% can increase its wear by up to 30% and negatively affect driving safety. Pits, speed bumps, curbs. from driving through them tire pressure drops.
We will tell you about what pressure should be in the tires of a car in winter and summer, and how its change affects the behavior of the car on the road and the wear of the tire tread.
Below in the text you will find tables of tire pressure of cars by make and size of wheels, in which the most popular car models are presented.
And it will be much easier for you to deal with all kinds of markings on the wheels, having at hand the decoding of the tire markings (construction indices, speed, tire load, etc.).
Optimal car tire pressure
The main task of car tires is to provide effective traction of the car with the road. At normal tire pressure, the load in the contact patch of the wheel with the road is evenly distributed, due to which tire wear occurs evenly, the car is well controlled and fuel consumption is within normal limits.
There are three possible ways in which the tire pressure will not be optimal:
- Increased pressure (tires inflated);
- Low pressure (tires under-inflated);
- Different pressure in all wheels.
Check the tire pressure with a special tire pressure gauge. This should be done only on cold tires, that is, before leaving the parking lot or garage.
In the event of deviations from the pressure in any of the tires (see the table below, what pressure should be in the tires of your car), such a wheel must either be pumped up or excess air must be released from it. that is, it is necessary to bring the pressure to the norm. In one of our articles, we have already talked about which car compressor is better for inflating tires.
It is worth noting that the tire pressure in winter should be exactly the same as in summer. But due to the sharp temperature drop, in the winter period of time it is necessary to approach the air pressure control in the wheels more responsibly.
It is better to inflate the wheels on the street. Also, do not forget to check the tire pressure in case of significant changes in the ambient temperature, and, if necessary, correct it:
- if it gets colder outside, the pressure in the tires will decrease,
- and when it gets warmer, it will rise.
It should also be remembered that when the car is moving, the tires heat up, the air in them expands, and the pressure increases, and the handling and braking properties change.
Increased tire pressure
With increased tire pressure, the load at the points of contact of the wheel with the road acts more on the central part of the tire tread, thereby causing uneven tire wear.
On over-pumped wheels, the car slows down worse! This is because if the tires are pumped, then the contact patch with the road decreases, which means that the friction force that keeps the car from sliding decreases. In this case, the braking distance is noticeably increased.
In just twenty minutes of driving, while cornering as aggressively as possible, the tire pressure of a car can increase by 0.5 atmospheres. And on long trips at high speed, the pressure in the tires can increase up to 4-5 atmospheres. And modern tires are designed for this.
But if the tire has a hernia or a cut, then it can get hot and explode on the go. And on the road it’s a disaster.
Low tire pressure
Lowered only to the floor of the atmosphere, the wheels change the behavior of the car and become unusable much earlier. Under reduced pressure, the load on the tire surface is unevenly distributed. In this case, the lateral sides of the tire are exposed to increased wear at the point of contact of the tire with the road.
The sidewalls of the flat tires are softer and are crushed when the steering wheel is turned. The trajectory of the disc and the tire does not match, so the car reacts to the steering wheel with a delay.
over, if the pressure in the tires is lowered, then the wheel can be completely disassembled at a sharp turn. Therefore, it is very important to regularly check the tire pressure and maintain it within the norm.
This is especially true in the winter period, since in the cold the tire pressure can easily drop by 0.3 (or even 0.5) atmospheres.
It should also be borne in mind that low air pressure in the wheels leads to increased fuel consumption. Just in case, we remind you that our site has an excellent selection of tips on how to reduce fuel consumption on a car. be sure to read, for sure, you will find something new for yourself.
Different tire pressures
The most common situation among drivers is when the pressure on all wheels is different. There can be many reasons, for example:
- Defective spools;
- Uneven tire wear;
- Or perhaps the wheel has caught a nail.
In case of emergency braking, in this case, the coefficient of adhesion to the road for inflated and lowered wheels will be different, which with a high degree of probability will lead to a skid or a turn of the car across the road.
If the car even starts to drive to the side a little, there is a reason to check how the wheels are inflated. And remember that there are no eternal tires. Even very good rubber needs care.
Tire pressure tables by car make and wheel size
Below we give a table of tire pressure of domestic cars VAZ, GAZ and UAZ. If you need a table of tire pressure for foreign cars, then you can download it from this link.