There are few things more irritating on a bike ride than getting a flat tire. And while some flats are unavoidable – like hitting a sharp rock – a flat caused by improper tire maintenance is NOT one of them!
Ensuring your bike tires are properly inflated is one of the most effective ways to minimize your risk of flats and rim damage.
So how often do you have to pump your tires to make sure they stay at the correct pressure? Here’s a simple rule to follow that works for all tires and riding styles:
CHECK your tire pressure before every ride, and PUMP your tires when the pressure is below the recommended PSI. Tire pressure has a significant impact on your safety and ride quality. And since checking tire pressure is so simple, there’s no reason not to do it before every ride!
So let’s get into more detail about how to check your tires to make sure they’re at the correct air pressure…and how to know what pressure they should be at in the first place!
In this article, I’ll cover:
How to Tell if Your Bike Tires Need Air
The most accurate–and easiest–way to do this is to check them with a tire pressure gauge. This will give you an exact reading and let you know whether it’s time to adjust your air pressure. If you don’t have one of these, you can simply hook your tire up to your air pump and read that gauge instead.
For a lower tech option, try giving your tires a squeeze and note how they feel. This is more subjective of course, but if you get used to what your tires feel like at the correct pressure, with practice you’ll be able to notice when they don’t feel quite the same.
Also, take your bike for a test ride. If it feels sluggish or slower than usual, or if just sitting on the bike causes the tires to visibly flatten out, it’s time to pump those tires up a bit!
Reasons Your Bike Tires May Lose Air Frequently
Inflated tires should be able to hold proper air pressure for at least a week or two without the need to make adjustments…but this isn’t always the case. Here are four factors that may explain why your tires are losing air faster than you think they should:
1. The Type of Bike Tire You Use
Different tires are rated for different air pressures. For instance, road bike tires are usually rated at 80-120 psi; gravel tires at 40-80 psi; and mountain bike tires at 25-50 psi (though all these values will be lower with tubeless tires).
Psi (pounds per square inch) is the amount of pressure air is exerting on every square inch of the tire from within. The average road bike tire is experiencing 3-4 times the amount of force from air pressure as compared to the average mountain bike tire. That’s a huge difference!
So it shouldn’t surprise you to find out that road bike tires tend to lose air more quickly than mountain bike or gravel tires.
2. Tires are Worn Out or Damaged
The inability to hold proper air pressure may be a sign that your tires are old, damaged, or just plain worn out. It’s possible that your tire could have a very small puncture or tear that’s too small to see, but large enough to allow air to escape.
If you think this is the case, you can try the good old soapy water technique: with your tire inflated, cover it with soapy water and watch for bubbles. This will show you where any air is leaking out. Small punctures can be patched, while larger ones will call for a tire replacement.
Even brand new tires can wear out if they’ve been stored for a long time in poor conditions, so if you have tires that have been collecting dust in your garage for years, make sure to check them before slapping them on your bike.
3. Defective Valve
Your tires might be in great shape…but if you’ve got some leaky valves, the air isn’t going to stay where it should!
A defective valve won’t stay sealed properly, and will cause air to slowly leak out. If you run tubeless tires, sometimes tire sealant can work it’s way into the valve. When the sealant is exposed to the air outside, it gets all gunky and may prevent the valve from sealing shut.
This has happened to both of my tires now, and while it’s annoying, luckily it’s a quick (and cheap) fix. There’s no need to replace the whole tire–simply deflate the tire completely, unscrew the valve core (you can use a specialty tool or a pair of pliers), clean it, replace it and you’re good to go!
4. Outside Temperature
Temperature has a dramatic effect on air pressure. As temperature increases, air expands. As temperature decreases, air contracts. The same thing is happening inside the closed environment that is your bike tire. In fact, a 10 degree change in air temperature can result in a 1-2 psi change in air pressure.
When the temperature increases, the air inside your tire expands, causing greater pressure on the tire wall. This increase in pressure could cause the tire or valve to leak. If the temperature decreases, you may notice your tires get squishy simply because the air inside has contracted and is taking up less space.
Either way, it’s a good thing to know if you live in a place that experiences dramatic temperature swings or you travel to and ride in locations with very different climates.
It’s also a good idea to deflate your tires when traveling and inflate them once you arrive at your destination: this will minimize the negative effects of rapid air expansion or contraction inside your tire and improve their lifespan.
What PSI to Pump Your Tires To
If you want the simple and easy solution, you can just inflate your tires to the PSI range recommended on the sidewall of your tires.
But, if you want to get your tire pressure tuned more precisely, there are a few other things to think about.
How much you inflate your tires is dependent on your weight, the style of bike you ride, and the terrain you’ll be riding on. Your desired air pressure will also be influenced by whether your tires are tubeless or not, and will even differ slightly between the front and rear tires.
As a general rule, a heavier rider will run higher pressures than a lighter rider, and the harder the terrain you ride on, the higher you’ll want your tire pressure to be.
If you’re a road biker or ride on trails with lots of exposed rock, higher tire pressure will help prevent damage to your rims caused when the tires deform too much on hard surfaces. If you ride on softer surfaces, there’s less risk of getting a flat, so you can get away with lower pressures–which will also improve traction!
If you have tubeless tires–which lack inner tubes (duh) and use liquid sealant to plug any punctures–you’ll be able to run slightly lower pressures, as tubeless tires are at less risk of pinch flats (where the tube is pinched between the tire and the rim, causing a rupture).
Finally, a rear tire will generally require higher air pressure than a front tire, because more of your body weight will be centered over the rear tire. The pressure difference won’t be significant–maybe a few psi–but it’s an important note to consider.
As an example, I’m a 200 pound mountain biker who rides mostly on dirt and occasionally soft sand. I usually run my tubeless tires at 24 psi in the front and 26 psi in the rear. If I plan on riding rocky terrain (or practicing jumps with big landings) I’ll increase the pressure in my front and rear tires to 26-28 psi and 28-30 psi respectively.
So if my tires varied slightly from these pressures, would I really notice much difference?
Overinflated tires will provide significantly less traction; though they will also provide less rolling resistance and better protection from punctures and rim damage if you’re riding on harder surfaces or have a heavy landing.
Underinflated tires will roll much slower, making it difficult to carry speed and momentum. They will however offer more traction if the surface conditions require it. Try riding through mud, sand or soft dirt with overinflated tires and see how difficult that is!
There are so many factors that influence which tire pressure will be right for you; once you get it right though, you’ll notice that even the smallest of air pressure changes will have a drastic impact on your riding experience–and not in a good way!
For a great beginner’s guide on how to find the proper tire air pressure for you, CHECK OUT THIS ARTICLE.
A Simple Check…Significant Results!
Checking your tire pressure is very simple, and it’s one of the most important things you can do to improve your ride quality. But it’s also about safety. If your tires are too soft or too firm for the riding conditions, your traction and tire integrity will be affected.
Nobody wants to blow out a tire on a ride! And nobody wants to wipe out and get injured either. So add a tire pressure check to your pre-ride inspection: the few seconds it takes to do this will drastically improve your riding experience, and could save you money on replacement parts or hospital bills in the future!
Ever wondered if you can use a ball pump to inflate your tire? Check out our article on whether you can use a ball pump on a bike tire here.