Every rider needs to top up their bike’s tires with air and ensure they have the correct air pressure to avoid getting pinch flats on the road.
It’s best to do this before every ride, especially if you don’t use your bike every day. Bike tires—whether clinchers, tubular, or tubeless—tend to lose air and go flat from sitting, even when they’re brand new.
If you do use your bike daily, you should check your tires every 7 days for road bikes and every 14 days for mountain bikes (keeping in mind that tires with inner tubes deflate faster than those without).
And yet life gets in the way and we forget to do this as often as we should. Though the ideal thing to do is to make it a habit, here’s how you can check ad hoc whether or not your bike’s tires need to be refilled.
Your tires need to be inflated if you feel the bike is sagging or if the rim is hitting obstacles you’re riding over. Other signs of underinflated tires include unresponsiveness under braking and instability in turns.
Knowing the right time to check on the pressure and give your tires some air can be a challenge, especially for the beginner cyclist who doesn’t know how often to do this and what signs to look for.
So we put together this post to answer all of your questions.
Why Should I Keep My Tires Topped Up?
For starters, it’s the only way to prevent pinch flats.
A pinch flat, also called a “snakebite puncture,” occurs when the tires on your bicycle are so soft that the inner tube gets pinched between the beads of the tire and the edges of the rim—and gets flat from two identical punctures on both sides.
This type of flats are the last thing you want to get on the road. They’re hard to impossible to patch up with a couple of patch kits, and the holes are usually too big to seal with Slime sealant. (They’re also why seasoned cyclists always take one or two spare tubes with them on long rides.)
Not only that, but your tires wear out less when they’re inflated to the proper pressure.
When your tires are filled with the right amount of air, they roll with minimal resistance, wearing out slowly and evenly. When they’re soft and squishy, they rub against the road.
When that happens, they will become noisier than usual. That noise isn’t just the sound of softness; it’s the sound of your tires wearing out much quicker than they should.
Last but not least, topping up your tires is for your safety.
When cycling, the tires are the only thing that touches the ground. To keep it that way, especially when you’re going fast or making sharp turns, your tires need to be able to withstand the stresses. To do that, they need internal pressure.
The Signs of Low Tire Pressure
The tires look soft. Your bike’s tires are there to provide traction and grip, and to hold your combined weight with that of the bike.
The first (and most obvious) sign of underinflated tires is that they look soft. You can recognize this by the fact that the shoulders on the tires are sticking out and too much of the tire is touching the ground.
The rim’s hitting obstacles. Whether you’re on a mountain, hybrid, or road bike, your tires should be robust enough to handle the impact of obstacles. The rim is not designed to handle this impact and the tire shouldn’t get pinched. So, if you feel the rim hitting obstacles, it’s a sign that your tires require more air.
If you damage your rims, it can be particularly challenging to get them to seal, so ideally, you’ll want to avoid this. As most of your weight is held at the back of the bike, it’s important to ensure that the back tire has adequate pressure.
The tires feel unsteady or wobble when you turn. The back half of your bicycle handles most of your body weight, particularly when you’re turning a corner. When you put excess weight on the tire, it will be inclined to conform to the ground.
If your back tire lacks sufficient pressure, it will lose its shape as it conforms to the ground—making you feel unsteady and/or wobbly as you go into the corner.
The response time of your bike feels like it is lagging. If the pressure in your tires is too low, they start to conform to the ground too much, making riding the bicycle a lot more laborious.
More friction means more rolling resistance, so you’ll find it hard to get your bike moving, and your bike will lose the bounce it normally has with well-inflated tires.
The tires are noisy. Tires make a distinctive sound when they turn soft and start rubbing the road. While you may not hear this sound during rush hour because the noise pollution is too great, you can hear it on a quiet road.
When you spot any of these signs, stop and check the tire pressure.
How to Check Tire Pressure on a Bike
The easiest way is to use a tire pressure gage, either as a standalone gadget or attached to a bicycle pump. If you travel long distances, whether as a commuter, for recreation, or for training, you should always have a good bicycle pump with you.
The gage measures the tire pressure in PSI, or Pounds per Square Inch.
The easiest way to find the recommended PSI for your tires is to look for an engraved value on their sidewalls. Since you can overfill your tires (and you don’t want to), this will allow you to top them up with “just the right amount” of air to the recommended pressure.
If you don’t have a tire pressure gage or bike pump handy, go to the nearest gas station and use its air pump.
If you’re in the middle of the road in a rural area—and there are no gas stations or truck stops nearby—you can ask a homeowner for help or signal a passing car and ask the driver to lend you their pump for two minutes.
How to Check the Pressure Without a Gauge
A pressure gage won’t break the bank, and it’s well worth investing in for the time and energy it saves you on checking the pressure of your tires.
That said, if you need to check the pressure of your tires and you don’t have any tools, there are still a few methods you can use.
Squeeze the tire and see how it feels. This is not an exact science and is much easier for experienced riders who know what their bike “usually” feels like, so they can readily spot deviations from the norm.
Do the thumb check. This simple tactic has been around for many generations. It may not be the most reliable check, but it will give you a rough tire pressure gauge. Fill the bike tire with air and then pinch the tire just above the rim to see how tight it feels.
How Often Do Bike Tires Need Air?
When you fill your bike’s tires with air, you are pumping a lot of air molecules into the tight, confined space of the tube or inside the tubeless tire.
No tire is 100% airtight. Even with new tires and/or inner tubes, a small amount of air will escape every day, and the tires will lose pressure and need topping up within 1-2 weeks.
Tires tend to lose pressure faster when they’re aged or worn, especially if they’ve sustained a few punctures in their life. This also applies to patched or sealed tires as patches and sealants also wear out over time.
Generally speaking, clincher and tubular tires need air more often than tubeless tires do. But tubeless tires are not immune to pressure loss, and they do need to be topped up every couple of weeks even if they’re in mint condition.
Develop the habit of checking the pressure on your tires before every ride, even if you cycle daily. Not only will it save you from pinch flats, but it will also help you identify and fix punctures early on.
Knowing when your bike tires need air and having the tools to maintain an optimum PSI is essential for riders. The correct air pressure in your tires protects you and your bike and results in a smoother ride.