Having the right PSI in your bike tires can make a world of difference. However, it would be an oversimplification to say that less air offers a more comfortable ride and more air makes you go faster. While this is true in many instances, the fact of the matter is that proper inflation for optimal performance depends on the individual rider and his or her bike.
Every tire has a recommended psi printed on its side close to where it touches the rim. This is usually written as a range (for instance, "90 to 115 psi") since there are reasons why you'd want to be on the higher or lower end, which we'll get into shortly.
Basic rule of thumb if your tires happen to not indicate a recommended pressure: pump them up until they're firm but still slightly squeezable. Alternatively, there are generally-accepted ranges based on bike type:
| Bike tire type | PSI range |
| Kids' bike tires | 20–40 PSI |
| Narrow tires / road bikes | 80–130 PSI |
| Medium tires / hybrid bikes | 50–70 PSI |
| Thick tires / mountain bikes | 30 PSI (off-road) 50 PSI (on-road) |
Road bikes and tires are built for speed over smooth surfaces. Higher air pressure lets them roll easier and faster. A typical range for these would be between 80 and 130 psi, although racers can sometimes go as high as 160 psi. Quick tip if you're caught inflating a road tire without a gauge and need to ballpark it: at 100 psi, a tire can barely be compressed with your thumb.
Unlike roadies, mountain bikes are flying over loose, bumpy terrain. Tires with too much air lead to too much bounce, making for a jolty ride. Lower pressure helps with shock absorption while also giving you more traction since more of the tire comes into contact with the ground. MTB manufacturers recommend between 30 and 50 psi on most of their bikes since this is a nice balance between on-road (closer to 50) and off-road (closer to 30) riding.
Hybrid bike tires require pressure levels between those of road and mountain bikes. This is usually in the 50 to 70 psi range. Kids' bikes have the lowest recommended inflation, typically 20 to 40 psi.
Keep in mind that these are called "recommendations" for a reason, though. A number of factors go into the inflation process beyond just your style of bike.
Which leads us to…
Because nothing in life is ever as simple as it should be, we've included a few more things to ponder when it comes to making sure everyone's tires are in good shape for their next ride.
As a general guideline, more weight = more pressure. Whether you're competing in the Tour de Whatever or shredding up the backcountry, heavier riders should use a higher psi than lighter ones to see the same performance in their tires. For perspective, someone weighing in at 200lbs will probably want to pump in around 20 more psi than someone who's 160. There's no real slide rule for this, so just play around with the pressure and see what feels best for you. Also keep in mind that rear tires tend to carry more weight than those in front, so adjust accordingly as necessary.
We know through physics that temperature affects air pressure. So, all else being equal, people biking in Miami in August are going to have higher pressure in their tires than people biking in Boston in January. In addition to weather, sustained deceleration using rim brakes generates friction that can increase temperatures inside the tube significantly. Fortunately, they also cool off relatively quickly, but it's something to keep an eye on during long descents. It may also be worth mentioning to your burgeoning roadster as he or she is learning the basics of hand braking.
In short, don't do either. If you overinflate, you run the risk of blowing the tube either while pumping or while riding due to sudden or constant impact. If underinflated, the low pressure could cause pinch flats. This occurs when the tube becomes squeezed between the rim and tire casing by hitting a bump with an underinflated wheel.
Not only does this damage the tire, it can also hurt the rim. Plus, flat tires slow you down and make you pedal harder, which is just no fun.
"How often should I inflate my tires?" is a common question among many casual bikers. The answer depends on how often and how hard you ride. Some people break out the pump every few days, others once a week, and still others even less regularly than that. Even if you or your kids have left your wheels in the garage for months, air tends to seep out slowly, anyway. Therefore, as a bike-safety best practice, just like a car it's certainly never a bad idea to check your tires before each ride. Especially if it's been a while.
The pro's choice, floor pumps do a great job. They are easier to pump and attach, and will pump your tires up much quicker than a hand pump will. Some come with gauges, which eliminate 1) the need to switch back and forth between a pump and standalone gauge, or 2) if you're really lazy, outright guesswork.
However, some expert cyclists are cautious of floor pumps with gauges, as the accuracy of the gauge can svary and may be off by as much as 10 PSI. On the plus side, if the gauge is consistent you can calculate the difference and adjust your target PSI to compensate.
It may be tempting to simply use the air compressor at your neighborhood Exxon, but these are less than accurate and can often overinflate your tires (it's a gas station, they're meant for cars). For serious riders whose circuits take them far from home, a small hand pump can help you change a flat on the fly. Carbon dioxide inflators accomplish the same thing if you're an air-in-the-can kind of guy.
Essential for any enthusiastic cyclist, hand pumps are harder work to fill the tire with, and aren't as quick. But they're transportable, so you always have your pump with you. It's simply foolish to embark on any long distance bike ride without your trusty hand pump and puncture repair kit.
So there you go, we hope this quick guide to bike PSI pressure was useful. To recap: figure out what feels most comfortable based on your particular cycling style. Go with that. Keep an eye on your pressure, and check it before every ride. You'll get a feel for it over time. Like, literally.
Here’s a riddle: Your bike has a component that costs nothing and weighs nothing. But it is essential if you want to go ride. What is it?
Well, this story’s headline probably gave away the answer. It is the air in your tires.
Depending on your experience level, you might be able to gauge your bike tire pressure with a quick pinch of the tire. Or, you might be a little surprised to hear that bike tire PSI needs to be checked far more regularly than those on your car. This how-to guide is geared toward the latter group of cyclists, beginners. But hopefully, riders of every ability level can learn a little more about the precious pressurized air that keeps us all rolling.
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Pneumatic tires on any vehicle are supported by pressurized air in an airtight chamber. Higher PSI (pounds per square inch) makes the tire harder. Lower PSI makes it feel softer. Bike tire pressure has a huge impact on how a bike performs. Checking your tire pressure is the simplest and most important piece of regular maintenance you can perform.
So where do you begin if you’re new to cycling and just got a road, mountain, gravel, or cyclocross bike? Conveniently, every bike tire has recommended PSI stamped into the rubber on the sidewall. (Pro tip: If you’re mounting a tire, align that pressure rating next to the valve for easy reference.)
“Recommended tire pressure is about the intended use and the best range for that use,” says tire expert Johs Huseby, WTB’s Director of Global OEM Sales and Product Vision. “You need to find the sweet spot for a tire and figure out where the high pressure doesn’t have any risk of blowing off the rim and the low pressure won’t burp or rip off the rim.
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Most mountain bike tires are rated for 25-50 PSI. Road tires are usually 80-120 PSI. Gravel tires are often 40-80 PSI. While they are a good starting point, those ranges are too broad and conservative for most riders.
| Tire type | Tire width (approximate) | Recommended tire PSI |
| Mountain bike | 2.1-2.5" | 25 PSI |
| Gravel bike | 33-42mm | 40 PSI |
| Road bike | 25-32mm | 90 PSI |
| TT or triathlon bike | 25-28mm | 100 PSI |
These pressure suggestions are based on an average-sized male rider (about 160 pounds) riding moderate terrain. Heavier riders may prefer higher pressures and lighter riders may prefer lower pressures. Read on to learn about the variables that might lead you to add more PSI or take a little out.
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Having an easy-to-read tire pressure gauge is key to setting up your tire pressure. A lot of pumps will have built-in gauges. There is a chance these gauges are a bit inaccurate. If you suspect yours is off, that is fine, as long as you know what to expect and are consistent in checking your tires before each ride. If you’re really concerned, try comparing it with a pump that you know will read true, like one at your local shop or an accurate digital tire pressure gauge.
Ready to start tweaking your tire pressure for optimal performance? Let’s start with the basic principles of tire pressure so you can determine the right PSI for your bike. The key considerations are tire width, rider weight, terrain, and tubeless.
Generally, narrow tires, heavier rider weight, and rougher terrain require a bit more PSI. On the other hand, wider tires, lighter riders, smoother terrain, and a tubeless set-up make for lower tire pressure.
Here’s why.
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All tires require a certain amount of air pressure to prevent them from bottoming out on the rim. Wider tires have more air volume. This makes it possible to ride them at lower pressures for more comfort and traction. Conversely, a narrower tire, like a 28mm road tire has comparatively much less volume so it needs more air pressure to prevent bottoming out. If you have a 2.5” enduro tire on your mountain bike, you’ll be able to ride at pressures close to 20 PSI. Rolling out on the road bike with 28mm slicks? Anything less than 80 PSI would be risky.
You don’t have to be a physics Ph.D. to understand how your body weight interacts with tire pressure (heck, I didn’t even take a physics class in high school). Just sit on your bike’s saddle and watch how the tire compresses and deforms as more weight is applied. The idea is to strike a balance so the pressure supports your weight but doesn’t end up rock-hard.
Therefore, more rider weight requires more tire pressure. For example, I weigh about 150 pounds and ride 30 PSI on my gravel bike. A rider who is 20 pounds heavier should definitely consider another 3-5 PSI of air.
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Tire volume and rider weight are nice and predictable, but the terrain you’ll ride is not. This takes some trial and error to learn and mostly applies to mountain biking, gravel, or cyclocross. Eventually, you’ll be able to look at your local trails and tell which might require a little more air pressure (think: chunky rocks that might pinch your tire and smash your rim), and which are smooth enough to be ridden with softer tires for better grip in corners.
When you’re out riding, try to monitor the way your bike feels on bumpy terrain. Can you feel a harsh clunk when your wheel strikes a sharp rock? Your pressure might be too low. Does your bike seem skittish in loose corners and bouncy on rough stretches? Perhaps try dropping your PSI a bit.
For road riding, tire pressure won’t vary as much. However, the conventional wisdom of pumping up tires to a rock-hard 120-130 PSI has been debunked. Unless your pavement is glass-smooth, pressures in the 90-100 PSI range will be faster. The tire will absorb slight bumps and vibrations, which is faster than an unyielding, hard tire. You’ll also get more grip in the corners. If you ride in wet weather, slightly less pressure would also be prudent to improve traction.
“Over the last few years, we’ve dropped our PSI ratings even on the narrower tires by 10-15 PSI,” Huseby says. “WTB, coming from the dirt side of the spectrum, we’ve always erred on the lower side.”
Tubeless technology is now widespread in the cycling world, with the exception of some road wheels and tires. This can also affect your tire pressure. Because tubeless systems don't rely on an inner tube, you will be able to run a little less pressure and not worry about pinch-flatting your tire.
You’ll get better traction and comfort with less pressure which is beneficial for mountain bike trails and gravel roads. To learn more about tubeless systems, see our Beginner’s Guide to Tubeless.
The final consideration when it comes to tire pressure is worth its own section in this article, and even that won’t be enough space to truly explore every nuance of how tire pressure influences a bike’s performance. The primary factors are traction, rolling speed, and comfort. Ride with the correct tire pressure and you’ll be able to maximize all three variables. Too much or too little pressure can compromise tire performance.
As hinted at earlier in this article, lower tire pressure usually improves traction. This is because it increases the tire’s contact patch on the ground. A tire at lower PSI better conforms more to the ground it is rolling on, also improving grip.
Traction is essential in many situations, from cornering to climbing to braking.
In each case, better traction lets you overcome your bike’s inherent tendencies. Forward momentum makes cornering more difficult, but if your tire grips well on a loose dirt corner, you’ll be able to change direction with the right technique and rider input. Momentum also works in opposition to braking forces. With the right tire pressure to achieve grip on loose surfaces or wet pavement, you’ll be able to stop or slow down quickly and more safely.
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Your bike will feel more comfortable with the correct tire pressure. Like traction, this performance quality improves with lower pressure. The comfort afforded by lower pressure can be noticed on all of your bike’s touchpoints, from your feet to your saddle to your hands and shoulders.
There is a limit to how soft we’d want our tires to be, though. We love the increased traction that comes with low PSI, but eventually, a tire gets so soft that it has too much rolling resistance, making our bike feel slow.
This will be most noticeable on hard, smooth surfaces like pavement. Too-low tire pressure can also hamper bike handling by making the front end resistant to steering input or causing the tire to roll excessively on the rim during cornering.
The first step you can take toward totally geeking out on tire pressure is to adjust your PSI mid-ride to tinker with how your bike feels. This is something that’s most applicable to mountain, gravel, or cyclocross riding, but there’s always a chance you might encounter a surprise rain shower on a road ride that will necessitate a little less pressure.
It’s always easier to take air out of your tires during a ride than to add air back. When in doubt, start a ride on the high end of the PSI scale and let out air little by little, going off of feel. See if you can notice an improvement in traction. Be careful not to take too much out if you’re riding rough trails.
Mountain bikers often like to run slightly less pressure in their front tires, and that’s something you can experiment with too.
The idea is that, due to body position, you have less weight on the front tire, so you can get away with lower PSI, thereby enjoying more traction for cornering. With more air volume in a 2.2-2.5” mountain bike tire, pressure can be fine-tuned with great effect.
“On a drop-bar bike, I tend to run pretty similar pressure, maybe in the front, I have two to three PSI less if I can even control that,” says Huseby. “On a mountain bike, I definitely run less in the front than in the rear, up to five PSI.”
The last thing mountain bikers can consider when playing with pressure is a new technology generally called a tire insert. The category’s “Kleenex” brand is CushCore, so you might hear fellow riders refer to inserts that way. No matter the brand, the general idea is to put a foam ring inside a tubeless tire, which will reduce air volume and protect your rim from damage. Inserts allow you to run lower pressure with fewer drawbacks. If that rabbit hole looks enticing, check out our recent article on tire inserts.
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You might be the type to tinker with your PSI, or you might prefer the set-it-and-forget-it approach. Either is fine if you have a grasp of the fundamental balancing act that goes into deciding on how much to pump up your tires. You find that balance point by going low enough to maximize traction and comfort without risking flat tires or sacrificing rolling resistance and handling.
Compared to most vehicles, a rider on a bike is very lightweight and slow-moving, making the correct tire pressure far more important from a performance standpoint. Remember, air is free, so make sure to use it to your advantage whenever you’re headed out for a ride!
Edited: 01/25/2018
You came in the morning to your iron horse and you see - the wheel has flattened.
How to download it? Correct pump. And how to pump up correctly ? How many atmospheres Do beginners often think about it. Previously, as they did. I pumped up the wheel, tried it with my fingers - it is pressed through or not. He sat down and looked at the wheels - sold through or not. Sold - pumped up, not sold - went. It was called - to check "for a bulging naval eye."
It turns out that not everything is so simple.
With a properly inflated tire, the ride is pleasant and easy. It provides good rolling, speed, tire wear resistance and, in the end, the safety of the cyclist.
You need to understand that pressure is not kept by the chamber, but by the tire.
The pressure for which the tire is designed is indicated by the manufacturer directly on it.
The inscription in English " Inflate to ... " literally translates as "Inflate to ..." ("Inflate to", "Pressure from ... to ...").
For example, the figure indicates that the pressure should be from 36 to 60 PSI (from 250 to 420 kPa) or 2.5 atmospheres to 4.2 atmospheres, respectively.
The relationship between BAR, PSI and Pa is: , but with the translation of Bar to PSI, everything is a little more complicated, so here is table for quickly converting pressure in bicycle tires from Bar to PSI and vice versa :
Let's mention another pressure designation, which is called "kilogram force per square centimeter" or "technical atmosphere" and is denoted as " kgf / cm² " or " kgf/cm² ". It is quite rare, but it does happen. We will dwell on the technical nuances, there are a lot of articles on this topic on the Internet, let's just say that for bicycle pressure it can be considered equal to 1 Bar or one atmosphere.
And for fans of exact mathematics, here are the conversion factors:
1 kgf / cm² = 1 atmosphere = 0.
98 Bar = 98.07 kPa = 14.22 PSI
When inflating a tire, you need to clearly understand that the pressure in it should not be lower than the minimum specified and higher maximum. It is worth noting here that it is better to leave a small margin of 0.2-0.5 atmospheres without inflating the tire to the maximum value so that it does not burst, especially in hot weather.
About what else the manufacturer writes on bicycle tires, as well as what other numbers mean on it, there is a separate article on our website, which is called "What do the numbers on bicycle tires mean".
To be honest, without a pressure gauge, nothing. So you need a bicycle pump with a pressure gauge, a separate pressure gauge connected to the nipple, or you will have to inflate tires at a service station - they always have something to measure the pressure in the wheels. You have to be careful with STO. There are times when a valiant worker, forgetting about pressure, hits the wheel with everything he can and the camera, together with the tire, explodes in a matter of seconds.
There is one piece of advice. When you know exactly what pressure is now - try to squeeze 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 rather tight to the touch.
If the pressure is low, the tire can easily puncture. In addition, under-inflated wheels extinguish a large percentage of the cyclist's efforts to accelerate and actually ride. The tire "spreads out" on the asphalt and, moreover, wears out very quickly from high friction on it.
This also leads to the so-called "snake bites" - two adjacent breakdowns. Occurs when a sharp collision with 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 run into, and breaks through in two places at once.
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.
In this case, if the wheel is heavily pumped, it can easily pierce the rim (on the side of the spokes). To protect the camera from this, a special rim tape is used. This is a rubber or polymer strip that fits over the rim to keep the ends of the spokes and the sharp edges of the spoke holes from piercing the tube. So a middle ground is needed. An example 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 feel). Remember that it is not only the nipple that poisons. The air is also slightly etched 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 thing. When driving, the main load falls on the rear wheel, while the front is not so heavily loaded.
Based on this, it is possible to do a little more pressure in the rear tire than in the front . On average, somewhere around 10%.
For driving on asphalt and well-packed dirt roads, you need to pump up the maximum pressure.
The easiest way to inflate wheels for road and city bikes - slicks. 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 feel free to pump a little bit by 0.2 - 0.4 without pumping up to the maximum pressure indicated by the manufacturer on the tire, especially in hot weather.
For semi-slicks, it is important to choose the right pressure for the exact surface on which the bike rides.
Driving on hard surfaces - asphalt and packed dirt. At low pressure, all the advantages of these tires are lost.
A properly inflated semi slick should roll on a hard surface with the smooth part of the tread. And on soft ground, the side lugs come into play. At low pressure, the tire will flatten and cling to a hard surface with its side lugs, creating additional resistance and wearing out faster.
When driving on soft ground, it is better to reduce the pressure. The low pressure absorbs bumps in the road and makes off-road driving more comfortable. At the same time, the area of contact between the wheel and the road increases, which, accordingly, leads to an improvement in grip. This is especially felt on the descents and sharp turns.
When riding on sand or snow, it is better to increase the pressure - the grip will improve and the bike's handling will increase.
All toothy tires designed for travel on soft ground, sand, snow are best used with high pressure. In this case, the adhesion will be maximum.
If the temperature is high, it is better to reduce the pressure a little. Be aware that the wheel may overheat. The hot asphalt itself and the friction of the tires on it heat the chamber and the air inside it, which accordingly increases the pressure. So a tire inflated to its maximum value in a hot summer can suddenly explode.
More details about the effect of air temperature on tire pressure are described in a separate article "Tyre pressure versus temperature". There are also calculation formulas.
Here, for example, we give a table for determining the pressure in the bicycle wheel from the air temperature, if it is inflated at a temperature of +20°C.
At low temperatures and in winter, things are a little more complicated.
When riding on loose snow, keep the pressure at or slightly below the average value 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 when there is not much snow on the road and it is not wet - then the rubber will give maximum grip. The spikes will "bite" into the surface.
In other cases, it is better to keep the pressure low - the tire will "spread out" on the road surface and have better grip.
Precise recommendations for winter skiing are not easy to give. A lot depends on the type of tread, road condition, actual air temperature (-20, 0 and +5 are different things), snow moisture, weight and experience of the cyclist. In addition, winter roads do not always have one type of coverage, especially in the city. In some places, the road has been cleared to asphalt, in others there is a dense crust of compacted snow and ice, ice, and in some areas there is just an ordinary snow cover of 10-20 centimeters.
The answer to the question "How much pressure to keep in the tires 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 -10, and in the afternoon zero or even positive temperature, 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 have a small pump and pressure gauge with you at all times.
Often on Internet forums, cyclists argue about how much pressure to keep in the tires in winter, but in their assessments they do not always mention the specific nuances indicated above, which confuses beginners.
Another small nuance for the cold season. If the wheels rock in a warm room (at home, in a garage), then do not forget that outside, where the temperature is lower, the pressure will drop a little. How much it will fall depends on the specific temperature and can be seen in the table above.
This needs to be clear right away. The tire pressure of the road bike always varies between 6.5-9 BAR (up to 130 PSI) and does not depend very much on the weight of the cyclist.
The pressure in mountain bikes is always lower.
Here is a table showing the pressure in the tires of a mountain bike and a city bike as a function of the biker's weight:
You can focus on the following - for each additional kilogram of weight, the pressure should be increased by 1%.
Tire pressure directly affects tire life. Riding on poorly inflated tires wears them out quickly.
First of all, you need to look at the limits that are written on the tire and certainly the pressure should not be less than the minimum indicated. Further, the bulk of children weigh up to 50 kg.
, Therefore, for them, the pressure in the wheels of children's bicycles must be maintained at a level of approximately 2 - 2.5 atmospheres. To the touch, this is a rather tight wheel and it is rather problematic for an ordinary person to squeeze it with their fingers. It is not worth pumping children's wheels, otherwise the ride will be very tough.
If your child weighs more than 50 kg, the tire pressure must be taken from the table above.
When riding a mountain bike in the city and on a rolled primer, this is 3-3.5 atmospheres. For movement on the ground - 2.5-3 atmospheres
At the same time, if your weight is more than 80-100 kg, feel free to add another 0.5 atmospheres to the wheels (be careful not to go beyond the maximum pressure).
If you have a road bike - feel free to inflate 3.5-4 atmospheres, looking at the limit values indicated on the tire.
The general principle is: The narrower the tire width, the higher the tire pressure .
Another point from the experience of cyclists. If you are using puncture protection tape, try to keep the tire pressure slightly higher. Everything is simple here: the higher the pressure, the denser the tape lies between the chamber and the tire, it does not “fidget” and does not move during sudden braking and cornering, and performs its function better.
Remember, you can find the optimal pressure for yourself only by riding a bike for a while. Every cyclist has their own weight and riding style. In this case, the same pressure for one will be optimal, and for someone too low or high.
Download, ride and enjoy!
When buying a bike, many do not even think about the fact that the convenience and comfort when riding it is achieved by properly selected tire pressure.
The service life of the bicycle, the speed of riding, the degree of tire wear, safety, control of the two-wheeled friend depends on how the wheels are inflated.
Many cyclists believe that inflating the tires is only necessary for a good bike ride. However, flat tires have a wider area of contact with the road, which means that grip will be better, but it will be very difficult to accelerate to a speed of 30-35 km / h on such tires.
When inflating your tires, you should always consider the type of terrain or surface you will be driving on. If the walk is supposed to be on an asphalt road, the tire pressure of the bicycle should be close to the maximum allowable value. Elastic wheels on a flat surface will provide a smooth rolling and high speed of movement.
For cross-country riding with unpaved paths, it is better to set the tire pressure to medium tolerable, so that you can ride long distances in comfort and convenience.
At high pressure, the grip of the wheel with the road will be minimal, respectively, all holes, pebbles, and bumps on the road will be sensitive. And with flat tires, the likelihood of damage to the wheel or puncture of the chamber increases.
In order to protect yourself on the road, as well as to keep the bicycle or its individual parts intact, you need to know exactly the lower and upper limits of permissible values, to what pressure the bicycle wheels can be pumped.
Information about tire pressure gives you an advantage when cycling:
Forget the old "grandfather" way to check the wheel with finger pressure. No need to rely on tactile sensations, trying to feel with your hand the degree of rubber penetration on the tire. The air leaves the wheel gradually, through the pores in the rubber. Within 2-3 weeks, the pressure decreases by 0.1-0.2 atmospheres, but you cannot determine this with your fingers. The exact value at any time will help determine the pressure gauge that every cyclist should have in his arsenal. With its help, it is simple, with a minimum error, the level of pressure in bicycle tires is measured. A pump with a pressure gauge (floor or manual) will become an indispensable tool for cyclists.
There are three standard values in which bicycle tire pressure is measured.
kPa = 14.504 PSI
All these units are used to some extent - in different countries, by different manufacturers.
For residents of Russia and the post-Soviet space, the change in bars is more familiar, since this unit is clearly associated with the pressure of the 1st Earth's atmosphere at ocean level. In America and Western Europe, a popular unit is PSI, as they actively use pounds and inches in measurements. Pascals are the least used unit of measurement, but the most modern. Some bicycle manufacturers write data on the wheels about the allowable pressures in all three systems.
Manufacturers indicate on the sidewall of the tire how many atmospheres to pump the bicycle wheels. Specifies the range within which the owner of the "iron horse" determines the desired values, depending on the specific factors of riding his bike. Values in the range are labeled from min to max, in two or all three dimensions. Numbers up to 10 are atmospheres (or BAR), tens-hundreds are PSI, and six-digit values \u200b\u200band with the prefix “k” / kilo are Pascals.
When inflating a tire, you must strictly follow the manufacturer's recommendations and try not to go beyond both the minimum and maximum pressure levels indicated on the tire.
Moreover, it is better to leave a small margin of 0.2-0.5 BAR, both in one direction and in the other, so that the tire does not burst.
The pressure in the wheel is kept by the tire, not the tube, so there is no single standard for its value. There are several significant factors that determine how much you need to pump the wheels on a bicycle.
The type of tire is determined by the surface of the track on which the cyclist will predominantly ride. Accordingly, the level of inflation of the bicycle wheel will be different. There is a direct dependence on the roughness of the tread and the width of the wheel - the more lugs and the wider the wheel, the lower the pressure should be. Empirically, cyclists quickly determine how many atmospheres should be in the tires of their bicycle
Many cyclists do not think about the fact that air temperature affects the pressure level in bicycle tires.
From the course of school physics, we recall that when heated, bodies expand. This means that in hot sunny weather, the pressure inside the air chamber will increase without additional pumping. Conversely, on cold winter days, a decrease in tire pressure is quickly felt due to low temperatures. So, when going for a bike ride in the cold season, the pressure indicators need to be adjusted a little higher than usual, and in the summer heat, let the air out a little. It is worth noting that when going on a bike ride, you should always take into account the weather conditions.
It is important to take into account the load on the bike created by the weight of the rider, especially the fact that most of it is on the rear wheel. Therefore, the degree of its pumping should be slightly higher than the front, the optimal difference is 10%.
To calculate the optimal tire pressure for a bicycle, given the weight of its rider, you can use the table:
Rider weight (kg) Pressure (atmosphere) Pressure (PSI)
The nature, riding style and type of bike also affect tire pressure.
Buyers who prefer an active pastime often opt for mountain bikes with 26-inch wheels, which ride well both on city streets and in rough terrain.
To understand to what pressure to inflate the wheels of a bicycle, it is necessary to take into account the features of both the bike itself and other, at first glance, weightless factors. For example, weaving threads on a tire, rim thickness, driving style. The likelihood of a tire coming off a wide rim is much less than a narrow rim, because a wider rim will hold the tire better than a thin one. Mountain biking already by its name suggests the presence of a difficult surface on the track, with possible obstacles and bumps. The driving style is more aggressive than on a smooth, calm trajectory, it obliges you to increase the tire pressure to a level slightly less than the upper limit.
The diameter of the wheel will also affect the selection of the optimal pressure value, since the larger it is, the higher the volume of air pumped will be.
