What is the pressure in the tires of a bicycle 29

Road bike tire pressures. Table.

pressure, tires, bicycle

The pressure should be close to the maximum value written on the tire. Download to the max value, but it is worth noting that it is better to leave a small margin of 0.2–0.4 atmospheres. Under no circumstances exceed the maximum permissible value, the tire will simply burst.

What is written on the tires

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

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

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

In what and how is it measured?

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

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

Bicycle tire pressure 29 inches

Air pressure for different types of tires

If your bike has semi-slick tires, 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 grip 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 inflate to 2-2.5 atmospheres. These all-round tires are good for both off-road driving and quiet driving on good roads.

Pressure effect

In fact, the optimal pressure in the tires of a bicycle is a purely individual parameter that 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 rise to 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 over 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.

Pressure effect

In fact, the optimal pressure in the tires of a bicycle is a purely individual parameter that 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 rise to 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 over 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.

How to check chamber pressure.

Honestly. without a pressure gauge in any way. So you need a bicycle pump with a pressure gauge, a separate pressure gauge connected to the nipple, or you will have to pump up the tires at the service station. they always have something to measure the pressure in the wheels. You need to be careful with the service station. There are times when a valiant worker, forgetting about the pressure, hits the wheel with everything he can and the camera and the tire explode in a matter of seconds.

There is one piece of advice. When you know exactly what pressure is now, try squeezing the tire with your fingers. So gradually you will learn to determine the approximate pressure in the chamber by tactile sensations. Remember that already from two bars (atmospheres), the tire feels quite tight to the touch.

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If the pressure is low, then the tire can easily break through. In addition, under-inflated wheels extinguish a large percentage of the cyclist’s efforts to accelerate and actually ride. The tire spreads over the asphalt and, moreover, is very quickly erased from high friction against it.

This also leads to the so-called snake bites. two adjacent breakdowns. Occurs when a sharp run over a curb, stone or bump. In this case, the tire is pressed against the rim, the chamber is clamped between the rim and the object that the wheel has hit, and breaks through in two places at once.

How to set your mountain bike tyre pressures | MBR

Riding at low pressure can be dangerous for the rims, you can easily get an eight on the wheel. At low pressure, frequent punctures are possible, and when cornering, the tire can generally fly off the wheel, which is already life-threatening.

over, if the wheel is heavily pumped, then it can easily puncture the rim (from the side of the spokes). To protect the camera from this, use a special rim tape. This is a rubber or polymer strip that fits over the rim to prevent the spokes and sharp edges of the spoke holes from punching the tube. So a middle ground is needed. A sample of such a tape is shown in the figure on the right.

It is generally recommended to check the pressure before each ride (at least by touch). Remember that the nipple is not the only poison. The air etches a little through the rubber itself, albeit slowly. Because of this, every month, an inflated tire itself loses an average of one bar of pressure.

I would like to note one more point. When driving, the main load is on the rear wheel, while the front wheel is not so heavily loaded. Based on this, the pressure in the rear tire can be slightly higher than in the front. On average, about 10%.

Standard pressure

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 Tire

Not so long ago such a story happened in my life. Seeing that I was pumping up the wheels of a bicycle, a boy of 10–12 years old drove up to me and asked me to swing the wheels on his bike. As someone who cannot refuse such a simple matter, I connected the pump to his rear wheel. But not having time to do even 20 pitching, we saw with horror how cracks went along the tire and it burst, unable to withstand the internal pressure of the chamber.

As it turned out, this topic is quite extensive and correctly inflated wheels will give the bike better handling and cross-country ability.

Slicks

For driving on asphalt and well-rolled dirt roads, you need to pump up the maximum pressure.

Slick wheels are the easiest to swing for road and city bikes. Due to the fact that they have a small volume of wheels, the pressure must be high. The more pressure, the better the roll and the higher the speed. So swing boldly a little bit by 0.2. 0.4 under pumping to the maximum pressure indicated by the manufacturer on the tire, especially in hot weather.

What is the pressure in bicycle wheels in winter (at low temperatures or on snow)

Things get a little more complicated in cold temperatures and in winter.

When riding on loose snow, keep the pressure around or just below the average indicated on the tire. If the bike has a tread with large spikes, then it is better to increase the pressure almost to the maximum in the case when there is not a lot of snow on the road and it is not wet. then the rubber will give maximum grip. The thorns will bite into the surface.

In other cases, it is better to keep low pressure. the tire will flatten on the road surface and have better grip.

It is not so easy to give precise recommendations for winter skiing. A lot depends on the type of tread, the condition of the road, the actual air temperature (-20, 0 and 5 are different things), the moisture content of the snow, the weight and experience of the cyclist. In addition, winter roads do not always have the same type of coverage, especially in the city. In some places, the road is cleared to asphalt, in others there is a dense crust of compacted snow and ice, ice, and in some areas it is just an ordinary snow cover of 10-20 centimeters.

The answer to the question How to keep the pressure in the wheels in winter will come to you gradually, with the experience of travel. And it will not necessarily be exactly the same as that of cyclists in the north or south of the country. Indeed, in the north, the temperature rarely rises above 5, and in the south it jumps from minus to plus. And it happens that in the morning of 10, and at lunchtime it is zero or even above zero, and the pressure in the wheel has already changed, and the snow on the road is not the same as in the morning. It is best to always have a small pump and pressure gauge with you.

Cyclists often argue on Internet forums about how much pressure to keep in the wheels in winter, but in their assessments they do not always mention the specific nuances of the above, than they bring confusion into the heads of beginners.

Another small nuance for the cold season. If the wheels swing in a warm room (at home, in a garage), then do not forget that outside, where the temperature is lower, the pressure will drop slightly. How much it will fall depends on the specific temperature and can be seen in the table above.

What’s My MTB Tire Pressure Sweet Spot? | SportRx

Road bike tire pressures. Table.

The pressure should be close to the maximum value written on the tire. Download to the max value, but it is worth noting that it is better to leave a small margin of 0.2–0.4 atmospheres. Under no circumstances exceed the maximum permissible value, the tire will simply burst.

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

Let’s start with the very basics, here’s a bike going down the road:

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

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

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

Fatbike tire pressure

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

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

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

Fat rolls much better on loose snow if you pump less than 5psi. But reducing the pressure below this line for tube tires can be a bad decision. the bike starts to obey the steering wheel poorly, swim, the nipple can break or shear due to cranking 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, we went out to frost of 10 degrees, it became 4.3. Here is a table by which you can calculate the approximate dependence on temperature:

The pressure in the chambers depending on the outside temperature
Indoor temperature, ° C Outside air temperature, ° C
25 10 five -five -10 -fifteen -twenty
740 Atmospheric pressure, mm Hg
psi at room temp. psi outdoors depending on temperature
four 3.0 2.7 2,3 2.0 1.7 1,3 1.0
4.5 3.5 3.1 2.8 2.4 2.1 1.7 1.4
five 3.9 3.6 3.2 2.9 2.5 2.2 1.8
5.5 4.4 4.1 3.7 3.3 3.0 2.6 2.2
6 4.9 4.5 4.1 3.8 3.4 3.0 2.7
6.5 5.4 5.0 4.6 4.2 3.8 3.5 3.1
7 5.8 5.4 5.1 4.7 4.3 3.9 3.5
eight 6.8 6.4 6.0 5.6 5.1 4.7 4.3
nine 7,7 7.3 6.9 6.4 6.0 5.6 5.2
10 8.7 8.2 7.8 7.3 6.9 6.4 6.0

How much pressure should be in bicycle tires

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

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

Mountain bike tire pressures

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

High pressure maintains the semi-circular profile of the tire, while maximum grip is possible when the full contact patch is involved. In other words, the more the tire flattens, the better for flotation 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 man weighing from 75 to 90 kg. It is impossible to say more precisely. there are a lot of factors, you need to experiment with a specific tire and a specific trail where you ride.

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

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

Air pressure for different types of tires

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

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

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

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

Road bike tire pressure

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

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

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

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

How much to pump in tires in winter

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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