Are your tires inflated just right or are they a little low on pressure? What if you overfilled your tires? Neither are great scenarios to be in. Underinflated tires are likely to lead to a whole host of issues.
These include some tires wearing down faster than others, heat building up in the affected tire, difficulty braking, and a decrease in fuel economy. In some situations, your tire could even come off!
Overinflated tires aren’t much better. You’ll be uncomfortable as you ride since your overfilled tires handle differently. Your contact patch is lessened as well. Also, although it’s unlikely, overinflated tires could explode in certain conditions.
That’s why having the right tire pressure is so important. It’s not just for a smooth ride, but for a safe one, too. In this article, we’re going to tell you exactly what you need to know about bike tire pressure.
Table of Contents
What’s the Correct Tire Pressure for a Road Bike?
Let’s begin by discussing the tire pressure for road bikes and mountain bikes. What is the correct tire pressure for a road bike? There’s actually no one specific answer.
That’s why we recommend you consult your bicycle owner’s manual to get a tire pressure range to follow. If you by chance lost your owner’s manual, you can always check out this handy chart.
|Tyre Width||60kg / 132lb||85kg / 187lb||110kg / 242lb|
|23c||7 bar / 100 psi||8 bar / 115 psi||9 bar / 130 psi|
|25c||6 bar / 87 psi||7 bar / 100 psi||8 bar / 115 psi|
|28c||5.5 bar / 80 psi||6.5 bar / 94 psi||7.5 bar / 108 psi|
|32c||4.5 bar / 65 psi||5.5 bar / 80 psi||6.5bar / 94 psi|
|37c||4 bar / 50 psi||5 bar / 72 psi||6 bar / 87 psi|
Table courtesy of Cycling Weekly
As you can see, road bike tire pressure is dictated by several factors. These include the width of your tires and your weight.
Since this is a UK resource, the tire width is in centimeters. Let’s say you had bike tires that are 23 centimeters or about nine inches. You weigh 187 pounds. That means your tire pressure should be 115 pounds per square inch (PSI).
Let’s do another example. Now you have a bigger bike, one with tires that are 37 centimeters or about 15 inches wide. You weigh 242 pounds. You’d need a tire pressure of 87 PSI.
The bigger your tires, the lower the PSI. Just look at the above chart for confirmation of that. Tire pressure needs will always increase with your weight.
What about for a Mountain Bike?
If you’re riding a mountain bike instead of a road bike, the tire pressure is not going to be the same. According to ENDURO Mountainbike Magazine, the PSI varies if you have tubed or tubeless mountain bike tires.
If you use tubed tires that are between 2.35 and 2.4 inches, the pressure per tire should be 29 PSI. For tubeless tires that are the same size, the pressure should be slightly lower, just 26 PSI.
For larger tires, such as those that are three inches or bigger, the PSI increases. For tubed tires of that size, it’s 20 PSI, and for tubeless tires, it’s 18 PSI.
Want to know more about Fixing And Preventing Flat Tires?Check our article.
How to Check Your Bike Tire Pressure
If your bike tires aren’t completely empty, then they have at least some pressure. How do you know just how much pressure is okay and if your tires need to be inflated more (or even less)? You have to learn to read your bike’s tire pressure.
We recommend you use a tire pressure gauge if you’ve never tested the tire pressure of your bike before. While you can get a read without a gauge (and we’ll tell you how later), it can be difficult if you’re inexperienced.
First, you want to park your bike somewhere. Next, you want to figure out which type of valve your bike has. Here’s a pretty good guide we put together that should help you identify the valve on your own bike.
Once you’ve got that figured out, you need to connect the pressure gauge to the valve. Now apply some downward pressure. You should see the gauge’s needle jump up. The pressure reading you get is how full your tires are.
If your tire pressure is good, then you can hop on your bike and keep riding. If the pressure is higher than you want, you’ll want to release some air. Depending on which type of valve you have, the way you do so varies.
For instance, if yours is a Presta valve, then you’ll want to find the top of the valve and turn it. Now push down on the valve and you should hear air coming out. Do this in increments, checking the tire pressure as you deflate. You don’t want the tire pressure to be too low!
If it is, you can always fill the tires back up again. You have several options for doing so:
- a CO2 inflator
- a mini pump,
- or a floor pump
If you want to know the differences between inflators and pumps as well as which products we recommend, clickhere.
Can You Check Your Bike Tire Pressure without a Gauge?
No gauge? No problem! You’re not necessarily out of luck if you forgot your gauge at home or don’t have one to begin with. There are still ways to read your bike’s tire pressure. Let’s discuss these methods now.
The first one entails you grabbing your bike tire between your index finger and thumb. Squeeze the tire. If it feels a little empty, you might want to fill the bike up. If the tire feels very firm, then the tire pressure is likely too high. You should be able to pinch the tire ever so slightly. That tells you the pressure is good.
Another trick is using puddles to your advantage. Ride through a puddle and then to dry land. Do your bike tires trail a lot of water behind you? If you have a thicker water trail, then more of the tire was hitting the ground beneath the puddle. That means you could probably afford to inflate the tires up a little.
If you want a more scientific, reliable method of testing your bike’s pressure without a gauge, try a calculator. The PSI Calculator is a great choice. It accommodates for tire drop, which we’ll discuss in the next section.
Here’s what you have to calculate:
- How much your bike weighs
- How much you weigh (adding that to your bike weight)
- Tire length in millimeters
- Weight distribution of your bike
Once you have all that info, you’re good to go! The PSI Calculator will give you both the front and rear PSI for your bike tires. We recommend saving the calculator link to your phone and bringing it up when you’re on-the-go and want to test your tire pressure.
If you’re new to biking and testing your tire pressure, the PSI Calculator especially is a great replacement for a gauge. It takes a lot of the guesswork out, which ensures more accurate PSI readings even as a beginner rider.
Why Does My Bike Tire Keep Going Flat?
Why You Need to Check Your Bike Tire Pressure Regularly
No matter which type of bike you have, be it a road bike, a mountain bike, or anything else on two wheels, tire pressure is not one and done. Once you know your tire pressure, that only really applies to that one ride. The next time you go out on your bike, you’d ideally want to test your tire pressure again.
While any small weight fluctuations on your part are unlikely to influence your tire pressure, there are many other factors that could. How long did you ride? Using your bike will cause gradual tire pressure shifts.
Another major factor when it comes to your bike’s tire pressure is where you ride. Here’s a chart that appeared in Bicycle Quarterly to show you what we mean.
Image courtesy of Bicycle Quarterly
This chart, which comes from Frank Berto, measures what’s called tire drop. This determines the effect that pressure and load has on a tire. When this chart was first published, which was more than 20 years ago, it was determined that the tire drop should be about 15 percent.
Since today’s tires are bigger than those measured in the original chart, that tire drop percentage doesn’t hold as true anymore. Your tire drop may be higher or lower than 15 percent, but not by a huge margin.
Finally, one of the biggest factors that changes tire pressure is the weather. According to a 2014 Patch article, when the temperatures outside go up by 10 degrees Fahrenheit, your pressure will increase by at least one PSI. If it’s colder weather and you’re riding outside, for a 10-degree temperature drop, you’ll lose one PSI or more.
This time of year then, when the weather is still incredibly cold, you’ll more likely lose tire pressure. That means you can fill the tires on a Monday and by Wednesday you’ll have to fill them again because the weather is making you lose pressure.
You have to be careful in the summertime as well. After all, when you fill your tires, you get them to just about the correct pressure. All that heat and humidity can boost the tire pressure, which puts you at risk of overinflation. Test your tire pressure often!
Your bike’s tire pressure is not a static number. It changes depending on your weight, the bike weight, the type of bike you use, and the types of tires. The terrain you ride on and the temperature outside, hot or cold, can also increase or decrease the PSI.
That’s why we recommend you test your tire pressure often, at least every day before you ride. Whether you use a gauge or a calculator to get the right number, if you take care of your tires, they’ll take care of you.
Pump it up.
Proper tire pressure lets your bike roll quickly, ride smoothly, and avoid flats. Narrow tires need more air pressure than wide ones: Road tires typically require 80 to 130 psi (pounds per square inch); mountain bike tires, 25 to 35 psi; and hybrid tires, 40 to 70 psi.
50PSI in MTB tires is a lot! Unless you are on a heavy side or carry substantial load, that's in range for 32mm+ road tires.Should I inflate bike tires to max psi? ›
You should always keep your road bike's tires pressurized to be within the suggested range that is stamped on the side of the tires. That is usually 80 to 130 psi. Under-inflating and over-inflating can lead to serious problems.How many psi should a 26 inch bike tire have? ›
If you're inflating 26-inch tires (common on comfort and off-road bikes), you may find that the pressure range is wider, say "35 to 60 psi." This is because these tires can be used on and off road. For the former, 60 psi is about right because it rolls optimally on pavement.What tire pressure is best for speed? ›
In our example shown below, the vehicle manufacturer's recommended 35 psi for a 225/45R17 91W Standard Load tire installed on a vehicle initially rises in 1.5 psi increments for every 10 km/h (6.2 mph) increase in speed until the inflation pressures max out with an increase of 7.5 psi when the vehicle's top speed has ...Is 40 psi good for bike tires? ›
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.Can a tire hold 100 psi? ›
“If the load is in excess of 13,000 pounds, a load range H tire inflated to 120 psi should be considered.” But even a load range H tire won't support a 13,000-pound load at 100 psi. A low-profile LRH tire will need at least 110 psi, some as much as 120 psi.How do I know if my bike tire has enough air? ›
Most every bike tire lists its recommended pressure right on the edge of the tire's sidewall. It's usually a range, say from 35 to 80 psi (that stands for “pounds per square inch”). The only way to know how much pressure you have is by using a pressure gauge — squeezing your tire isn't accurate enough.Is 40 psi OK for tires? ›
Specifically, the level of 40 psi can be suitable for passenger cars or sports cars. But this is too high for small cars with a recommendation below 35 psi, while 40 psi is too low for large trucks. The recommended level for the tires of famous sports cars and passenger cars is between 32 -40 psi.Does higher psi make you faster? ›
Very high tyre pressures might feel fast, but they're not. Once you go past a certain point, adding more air to your tyres actually decreases grip, increases high-frequency vibrations and causes extra muscular fatigue. All of these things slow you down.
Overinflated Tires Wear Out Your Tires Faster & Unevenly
Uneven tire wear can also be the result of overinflation. When your tires have too much air it causes the center of the tread to bow out and wear first. Because of this you will need new tires more often and have a less than comfortable ride.
An overinflated tire can have less grip, too. And it can affect handling, because the overinflated tire is not correctly absorbing impacts, which can send more force to the vehicle's suspension. Overinflation also makes the tires' tread footprint smaller, which can increase wear on the center of the tread.Is 35 psi too high? ›
Most passenger cars' psi requirement will be between 30 to 35 psi, but several vehicles fall outside of that range and every vehicle will have specific requirements. Good tire air pressure ensures that tires wear evenly, provide a smooth ride, and increase fuel efficiency.Is 50 psi too much? ›
Press. 340 kPa ( 50 PSI)”. This means that the tire will safely carry up to 1477 lbs. and can be safely inflated up to 300 kPa (Kilopascal) or 50 psi (pounds per square inch).Is 42 psi too high? ›
“Recommended cold tire pressure is in vehicle manual and on tire label. It's usually 30 psi for small, 36 psi for medium, and 42 psi for large car.”How do I know the correct tire pressure? ›
Your vehicle's recommended tire pressure can typically be found on a sticker inside the driver's door. It's also usually listed in the owner's manual, says Cars.com. Tire pressure is measured in pounds per square inch (psi). You may also notice that the sidewall of the tires lists a tire pressure.What is dangerously low tire pressure? ›
If you have standard passenger tires (ninety percent of vehicles do) the lowest tire pressure you can generally drive with is 20 pounds per square inch (PSI). Anything under 20 PSI is considered a flat tire, and puts you at risk for a potentially devastating blowout.Does PSI affect speed? ›
This used to be one of the first things you learned as a cyclist: If you want to go fast, make sure your tires are pumped up to the maximum pressure. The harder your tires are inflated, the faster they roll. We now know that this is not true.Is bike psi same as car psi? ›
Higher tire pressures
Average car tire pressures are around 30-35 PSI. Average bike tire pressures vary widely, getting higher as the tires get narrower. Road tires often will need up to 80 to 110 PSI to stay fully inflated.
A common air pressure for one these would be 55 front, 80 rear, or 75 front and rear, or like the example above, 50 front and 65 rear. Since weight capacity is a simple function of air pressure times air volume, the higher pressure is necessary to enable these vechicles to do their job.
No, the tire is absolutely safe at its 44 psi max inflation pressure, but the car will ride a bit firmly and the center of the tread will wear considerably faster.What tire pressure do pro cyclists use? ›
In general, for fast road racing, a 25 or 28 c tire will be perfect. The last major consideration for tire pressure is rider weight- heavier riders will need to pump their pressures higher than lighter riders, due to the increased forces on the tire and wheel system.What is the highest tire pressure? ›
35 PSI. ' (pounds per square inch). That number tells you the maximum cold pressure needed for your tire to carry its maximum load. Most typical tires require about 32 to 35 pounds per square inch (PSI) of air, says Rod Tate, owner of highly rated Colony One Auto Center in Stafford, Texas.What tire has the highest PSI? ›
According to Berger the maximum inflation pressure for modern tires is typically between 44 and 51 PSI (pounds per square inch). If a driver inadvertently puts too much air in a tire it won't necessarily cause any damage, but it will impact other aspects of the vehicle.What happens if you over inflate a tire by 10 psi? ›
Tires will wear out prematurely. Overinflated tires round out on the tread section and cause the center to wear down significantly faster than the outer edges. This could cause them to last only half as long as they typically would. Overinflation can cause loss of traction.What is the 4 PSI rule? ›
Ideally, they should be about 4psi above the cold pressure. If the pressure is more than 4psi above the cold pressure, you should add more air. That is because there is too much friction, which builds up more heat than desirable. Conversely, if they are less than 4psi above cold pressure, the cold pressure is too high.Is it better to over inflate or Underinflate tires? ›
Under-inflated tires are just as dangerous and costly. Like over-inflated tires, under-inflated tires also cause blowouts. When a tire is under-inflated, more of the tire's surface area touches the road. This increases friction, which increases heat and leads to advanced wear.Why do bike tires lose air so quickly? ›
Road bike tires lose air for two main reasons: because rubber tires are porous and naturally allow air out through tiny pores, and because there's an object in the tire or some other kind of wear that has made the tire susceptible to air loss.What happens when you over inflate a bike tire? ›
What happens if people over inflate a bike tire? It will result in a rougher, less comfortable ride. At higher levels of inflation, it can cause loss of traction on uneven surfaces, or even explode.Is higher or lower psi better? ›
Low tire pressure always is more dangerous than high tire pressure. When tires are deflated, more rubber touches the ground, the tires heat up and you're in danger of a blowout.
Water pressure should generally be between 60 and 75 PSI inside your home.Does lower tire pressure give smoother ride? ›
A lower tire pressure makes the tire softer, meaning a smoother ride. This is a technique used by some who feel their suspension is too harsh. By decreasing tire pressure, it compensates for stiff suspension slightly. Lower tire pressure increases the contact patch with the driving surface.What are three 3 benefits of correct tire pressure? ›
Besides saving fuel and money and minimizing emissions, proper tire inflation is safer and less likely to fail at high speeds. Under-inflated tires make for longer stopping distances and will skid longer on wet surfaces. Properly inflated tires will last longer as they wear more evenly.Should front and rear bike tire pressure be the same? ›
Rider's position on the bike also means that the rear wheel carries about 60-70% of the total weight. Therefore, make sure you run the front tire pressure lower than the rear tire pressure. It should be around 2-3 PSI less, but it also depends on your position, discipline and riding style.Does tire pressure affect stopping distance? ›
When a tire doesn't have enough air pressure, it creates more friction. This friction can make it more difficult to get the car to a complete stop. In fact, low tire pressure can cause dangerously long stopping distances, which in the long run leads to crashes.What is the 6 PSI rule? ›
The 6 psi test for 4WD tyres*
If the tyres are correctly inflated, the pressure should have increased by around 6 psi above the cold pressure. If the pressure increase is more than 6 psi then your tyres are under inflated.
You may find that your tyres lose pressure or start to slightly deflate over time while the car is immobile. This is because rubber is porous, and while it's not enough to cause an issue normally, air molecules can make their way through the rubber slowly over a period of time.Is 100 PSI a lot? ›
For most houses, 80 psi (pounds per square inch) is about right. If the water pressure is over 100 psi, that's too much.What psi should a 20 inch bike tire be? ›
20-inch bike tires would generally use a PSI between 30 and 50.Is 40 psi good tire pressure? ›
Specifically, the level of 40 psi can be suitable for passenger cars or sports cars. But this is too high for small cars with a recommendation below 35 psi, while 40 psi is too low for large trucks. The recommended level for the tires of famous sports cars and passenger cars is between 32 -40 psi.
For instance, if 35 psi is recommended, and the maximum safe pressure listed on your sidewall is 44 psi, you can safely put 38 or 40 psi in your tires. You can even go to 44 psi. You'll experience a harder ride, but you won't create a blowout danger. You may even experience sharper cornering and increased fuel economy.Do bigger tires need more PSI? ›
Therefore, a larger tire needs less pressure than a smaller tire to carry the same vehicle weight.How do I know if my tires are too low? ›
- Vehicle is making a flapping sound while driving.
- The vehicle feels weird when turning.
- The vehicle takes longer to stop than usual.
- The vehicle is getting lower fuel economy than normal.
Very high tyre pressures might feel fast, but they're not. Once you go past a certain point, adding more air to your tyres actually decreases grip, increases high-frequency vibrations and causes extra muscular fatigue. All of these things slow you down.What is the 4 psi rule? ›
Ideally, they should be about 4psi above the cold pressure. If the pressure is more than 4psi above the cold pressure, you should add more air. That is because there is too much friction, which builds up more heat than desirable. Conversely, if they are less than 4psi above cold pressure, the cold pressure is too high.What happens if tire psi is too high? ›
Tire Damage and Wear
Excessive air pressure can also distort the shape of the tire, leading to decreased traction and increased wear and tear down the center of the tire. Depending on the circumstances, repeatedly overinflated tires could wear out more quickly.
Low tire pressure always is more dangerous than high tire pressure. When tires are deflated, more rubber touches the ground, the tires heat up and you're in danger of a blowout.Is 70 psi too high? ›
Normal psi for a home pipe system is between 30 and 80 psi. While you don't want the psi to be too low, it violates code to be above 80. Instead, you should aim for a psi that's between 60 and 70.