Why Do Bike Tires Lose Air? Top 9 Reasons & Solutions

Whether you ride the bicycle very often or leave it in the garage, its tires still become flat over time. We cannot have a smooth and safe ride without proper tire pressure. So why do bike tires lose air

In this piece, we share all the reasons for the problem. Read to the end to find solutions to stop bike tires from losing air over time.

why do bike tires lose air

Why Do Bike Tires Lose Air? 9 Reasons

Bike tires can lose air due to “air permeation,” where air gradually seeps through the rubber, even if there are no visible holes. Temperature changes, air leaks, or improper maintenance can also deflate the tires.

Below are the details of each reason causing bike tires to lose air.


Is it normal for bike tires to lose air? Bike tires losing air is totally normal since no tires are perfectly sealed so that air can escape gradually. Due to the nature of their material, this gradual loss of air is indeed a common occurrence.

Let us break it down to you in each science angle.

Air Permeation

Air permeation is like air molecules sneaking through tiny gaps in the rubber of your tire. 

The air permeation is a bit like water soaking through a sponge but much slower. The rubber isn’t completely solid, so that air can find its way out. The natural process happens to all tires, not just bike tires. As a result, your tires lose air.

Effects Of Temperature Changes

Thermal expansion and contraction is one of the factors contributing to air loss. 

When it gets hot, like on a sunny day, the air inside your tire expands. When things expand, they take up more space, and this can make the air pressure inside the tire increase. Higher pressure inside the tire can push air out even faster through those tiny gaps or imperfections in the tire. 

Conversely, the opposite happens on cold days – the air contracts, which can lower the tire pressure. 

Normal Air Loss Over Time

Even if everything seems perfect and you haven’t hit any bumps or sharp objects, bike tires can lose a little air.

The normal air loss over time in bike tires is scientifically rooted in the permeable nature of the tire material, where air molecules can naturally and slowly migrate through the material. From that, it starts a gradual decrease in tire pressure.

It’s like a slow leak, but there’s nothing to worry about. Over time, like weeks or months, you may notice your tire getting softer. That’s normal, and you need to pump it up again to the right PSI. 

Air Leakage

Tiny Holes or Punctures 

Tiny, sharp objects like thorns, nails, or bits of glass can puncture your tire. Even a minuscule hole can be enough to allow air to escape gradually.  

These tiny punctures can be challenging to spot, but they can explain why a bike tire loses air overnight.

Valve issues 

The next issue is the bike tire losing air through valve.

The valve on your tire acts like a gatekeeper for air. If it’s not securely closed or is damaged, it can become a pathway for air to sneak out. Even a tiny misalignment or a loose valve can cause slow air loss over time. 

Damaged Inner Tube

Why does my bike tire keep losing air? It is more likely that there is damage in your inner tube.

Inside your tire, there’s an inner tube that holds the air. If it gets punctured or torn, air will escape from there. These damages can be due to sharp objects, excessive wear and tear, or improper installation. 

Maintenance Neglect 

Failure to Check Tire Pressure Regularly 

It can gradually decrease if you forget to monitor your tire’s air pressure. You must regularly check and maintain the recommended pressure to avoid unexpected deflation during your rides.

Not Using a Proper Pump 

Using the right type of pump designed for bike tires is vital. A pump not intended for bikes may not provide the necessary pressure. Consequently, you can have under-inflated tires that can lose air more quickly. 

We recommend using a bicycle pump with a gauge to inflate your tires to the recommended pressure accurately. It will prevent unnecessary air loss.

Lack of Tire Sealant

Tire sealant is a special liquid that can fix small holes in your bike tire. Even a tiny thorn or nail hole can let the air escape when you don’t have this sealant inside your tire. 

But if you have tire sealant, it fills up those holes and patches up any leaks as soon as they happen. So, ensure you have this helpful stuff in your tire to keep it inflated and ready for your next ride. 

bike tire loses air overnight

How To Fix Bike Tire Losing Air?

Ensure Tire Pressure Range

To keep your bike tire from losing air, our advice is to start by ensuring it’s inflated within the recommended pressure range. Look for the suggested pressure on the tire’s sidewall, usually in PSI (pounds per square inch). 

Then, use a reliable gauge to check your tire’s current pressure. If it’s too low, pump it up to the recommended level. If it’s too high, release some air until it’s just right. 

Special Note: If your bike tire is equipped with a Presta valve, a standard pump won’t do, and you need to invest in an adapter. In emergencies, you can inflate Presta Valve without an adapter with our guide.

Tire Maintenance

Regular tire maintenance is key to fixing and preventing air loss. Inspect your tires for visible damage like cuts, punctures, or embedded objects, and remove them if found.

Besides, you must also ensure that the valve is tightly closed. If it is damaged, replace it. Don’t forget to apply a tire sealant to help prevent and fix small punctures. 

Moreover, check your tires for wear and replace them if the tread is worn down. Maintain a routine of checking your tire pressure and adjusting it as needed to keep your bike tires in optimal condition, ideally before each ride. 


Why do bike tires lose air? Now that you understand the reasons. The solutions are straightforward. However, don’t hesitate to seek professional help if you lack the technical skills. They can assist you and guide you through the necessary steps.

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