Bike CO2 Cartridge: Uses, Selection, and Guide
If you’re a cyclist, you’ve likely heard of the bike CO2 cartridge—a compact, convenient tool that can save the day when you’re stuck with a flat tire. But what exactly is it, and how does it work? This ultimate guide will walk you through everything you need to know about bike CO2 cartridges, from their purpose and pressure mechanics to how to choose the right one for your needs. Whether you’re a seasoned rider or new to cycling, this article will help you master the use of CO2 cartridges and understand their pros, cons, and lifespan.
What Is a CO2 Cartridge Used For?
A CO2 cartridge is a small, pressurized canister filled with compressed carbon dioxide gas, commonly used in cycling to quickly and efficiently inflate tires. Cyclists often rely on these handy tools to save time and energy, especially in emergencies or during competitive events where every second matters.
Compared to a manual pump, a bike CO2 cartridge can inflate a flat tire in just a few seconds, significantly reducing the time spent fixing a puncture and allowing riders to get back on the road or trail quickly. This makes it an essential item for anyone who values convenience and speed when dealing with tire issues.
CO2 cartridges are also versatile enough to handle both road and mountain bike tires. For road bikes, they can provide high pressure, inflating tires to 120 PSI or more, ensuring optimal performance. For mountain bikes, they deliver the necessary air volume to fill wider tires efficiently. Their compact size allows them to fit easily into a pocket or saddlebag, making them perfect for long-distance rides or high-stakes racing, where lightweight and portability are key.
Beyond cycling, CO2 cartridges are also used in other areas, such as powering paintball guns, inflating small inflatables, or providing air pressure for portable airbrushes. Their versatility and efficiency make them a valuable tool across a variety of applications.
How Bike CO2 Cartridge Pressure Relates to PSI
A bike CO2 cartridge holds compressed carbon dioxide gas at an extremely high pressure—around 800 PSI at room temperature. This pressure is far greater than what bike tires require, ensuring even a small cartridge contains enough gas to inflate a tire quickly and efficiently.
When you use a CO2 cartridge to inflate your tire, the high-pressure gas is released into the tire, raising its pressure to the desired level. However, the cartridge’s internal pressure is not directly linked to the specific PSI needed for your tire. Instead, it acts as a gas reservoir, and it’s up to you to control the release carefully to match the recommended PSI for your bike tire. Overinflation can damage the tire, while underinflation can compromise performance, making precise control essential for a smooth and safe ride.
Bike CO2 Cartridge Sizes and Tire PSI Chart
Bike CO2 cartridges come in different sizes (measured in grams), and each size holds a varying amount of compressed gas. The amount of gas you’ll need to properly inflate a tire depends on the type of bike and the tire’s size. To help you choose the right cartridge, here’s a handy guideline:
Tire size | 16 gram CO2 cartridge | 20 gram CO2 cartridge | 25 gram CO2 cartridge |
700C x 23 | 130 PSI | 80 PSI per half cartridge | 90 PSI per half cartridge |
700C x 25 | 110 PSI | 135 PSI | 150 PSI |
700C x 28 | 90 PSI | 110 PSI | 125 PSI |
700C x 35 | 60 PSI | 70 PSI | 80 PSI |
700C x 40 | 40 PSI | 45 PSI | 50 PSI |
20″ x 2.0″ | 50 PSI | 60 PSI | 70 PSI |
24″ x 2.0″ | 40 PSI | 50 PSI | 60 PSI |
26″ x 1.95″ | 30 PSI | 40 PSI | 50 PSI |
26″ x 2.0″ | 25 PSI | 35 PSI | 45 PSI |
26″ x 2.5″ | 20 PSI | 30 PSI | 40 PSI |
27.5″ x 2.0″ | 24 PSI | 32 PSI | 36 PSI |
27.5″ x 2.25″ | 22 PSI | 26 PSI | 32 PSI |
29″ x 2.0″ | 30 PSI | 42 PSI | 46 PSI |
29″ x 2.5″ | 25 PSI | 30 PSI | 35 PSI |
How to Choose the Right CO2 Cartridge

Choosing the right CO2 cartridge is essential for cyclists, as using the wrong one can lead to over-inflation or make it harder to control the gas flow. To ensure a smooth and safe inflation, it’s important to consider both your tire size and the compatibility with your CO2 inflator when making your selection.
Tire Size and the Right CO2 Cartridge
- Road Bike Tires: Road tires are narrow and require higher pressure, typically between 80-120 PSI. A 16g CO2 cartridge is usually sufficient to fully inflate these tires, making it the ideal choice for road cycling. Its compact size and ability to reach high pressure quickly make it a go-to for riders looking to minimize downtime.
- Mountain Bike Tires: Mountain bike tires are wider and require more air to reach the correct pressure, typically around 25-50 PSI. A 25g CO2 cartridge is better suited for these tires, providing the extra gas needed to properly inflate wider tires for off-road adventures.
- Gravel and Hybrid Bike Tires: These tires strike a balance between road and mountain bike tires in terms of size and pressure needs. For gravel or hybrid bikes, a 16g or 25g CO2 cartridge will work depending on the tire width and desired PSI, usually around 40-80 PSI. Larger tires may benefit from the extra capacity of a 25g cartridge for a complete inflation.
CO2 Inflator Compatibility
The CO2 inflator is an essential tool that works in tandem with your CO2 cartridge. Inflators come with different interfaces, and not all are compatible with every cartridge size.
1. Threaded vs. Non-Threaded Cartridges:
- Threaded cartridges (usually 16g and 25g) feature a screw-on design that fits inflators with a threaded valve. This creates a more secure connection and allows for greater control over the gas release, making them perfect for cyclists who prefer more precision when inflating their tires.
- Non-threaded cartridges (typically 12g) are made for inflators that use a pin to pierce the cartridge and release the gas. These are great for quick, one-time inflations, but they generally offer less control than threaded cartridges, making them less precise for those who need more accuracy.
2. Inflator Size
Choosing the right CO2 cartridge is essential for cyclists, as using the wrong one can lead to over-inflation or make it harder to control the gas flow. To ensure a smooth and safe inflation, it’s important to consider both your tire size and the compatibility with your CO2 inflator when making your selection.
How to Use a CO2 Cartridge: Step-by-Step Guide
For cyclists who have never used a CO2 cartridge to inflate their bike tires, it might seem a bit overwhelming at first. However, it’s actually quite simple to use. Here’s a step-by-step guide to walk you through the process.
Tip: CO2 inflation units have two main components: the inflator head (or nozzle) and the CO2 cartridge. The cartridge holds the compressed gas, while the inflator head is the tool that connects to the valve stem and releases the gas to inflate the tire. Depending on the type of inflator, the cartridge either slides into the head or screws in, with some inflators designed for threaded cartridges and others for non-threaded ones. This setup allows for quick and efficient tire inflation on the go.
1. Prepare Your Bike and Tools
- Before you begin, make sure your CO2 inflator is ready and compatible with your CO2 cartridge size (16g or 25g).
- Check that your bike’s valve (Presta or Schrader) is easily accessible. If you’re using a Presta valve, unscrew the tip to open it up.
2. Pre-Inflate the New Inner Tube (Optional)
While you can’t pre-inflate with a CO2 cartridge, it’s a good practice to lightly inflate the new inner tube with your breath to give it shape. This helps prevent it from getting pinched during installation. Simply unscrew the valve and take a couple of breaths to inflate it slightly.
3. Check the Tire and Tube Alignment
Before inflating, ensure the inner tube is properly positioned inside the tire and is not protruding, as this could cause the tube to burst during inflation. Take extra care to check this, especially when using a CO2 inflator, as the rapid release of gas can increase the risk of a tube blowout if the tube is not seated correctly.

4. Attach the CO2 Inflator to the Valve
- Once your tire and tube are properly aligned, attach the CO2 inflator securely to the valve. Make sure it fits tightly, whether you’re using a Presta or Schrader valve.
- Check that the valve on the inflator is properly aligned to ensure that gas is directed into the tire.

5. Screw in the CO2 Cartridge
- Now, screw the CO2 cartridge into the inflator. You’ll feel resistance as you screw it in, which is when the pin inside the inflator pushes into the cartridge to release the gas.
- Be prepared for a quick release of CO2 as the gas starts to fill your tire. Keep a close eye on your fingers since the inflator will get very cold during the process due to the rapid release of gas.

6. Monitor and Adjust the Pressure
- As the tire inflates, monitor the pressure closely. Many inflators have a pressure gauge, or you can use a separate gauge to check the PSI. Ensure you don’t overinflate, as this could damage your tire or tube.
- If you’re inflating to a specific pressure (e.g., 120 PSI for road bikes), stop once the desired pressure is reached. Some riders prefer to release a bit of air for precision.

7. Detach the Inflator and Check the Tire
- Once the tire is properly inflated, carefully detach the inflator from the valve. Tighten the valve cap if necessary.
- Double-check the tire pressure to ensure it’s at the right level. It’s important to note that CO2 will leak from your tire faster than regular air, so don’t be surprised if the tire loses a bit of pressure overnight.
8. Dispose of or Recycle the CO2 Cartridge
After using the CO2 cartridge, dispose of it properly. Most cartridges are recyclable, so check with your local recycling center for proper disposal methods.
Video: How To Use A CO2 Cartridge To Inflate A Bike Tyre
This video demonstrates step-by-step how to use a CO2 cartridge to quickly inflate a bike tire. It covers the basics, including attaching the cartridge to the CO2 inflator, connecting it to the tire valve, and properly releasing the gas to achieve the desired pressure. Watch it for more detailed guidance!
Pros and Cons of Using CO2 Cartridges for Tire Inflation
From my experience, CO2 cartridges are incredibly convenient but also come with a few trade-offs.
First and foremost, they are super easy to use. When I get a flat, I can inflate my tire in just seconds, which is a huge time-saver. The compact size is another big win; I can easily stash a cartridge and inflator in my pocket or saddlebag without adding much weight. For the price, they are quite affordable, and I don’t have to worry about pumping up a tire manually, which can be exhausting, especially during long rides or races.
On the downside, CO2 cartridges are single-use, so I need to carry extra ones, which can add up in cost if I’m on long trips. They also leak air out faster than regular air, so I’ve learned to check my tire pressure again sooner. While they’re great for convenience, I’ve read that CO2 can have a negative impact on the environment, as it’s a greenhouse gas. Also, the cold temperature when releasing the gas can be a little uncomfortable, and if you’re not careful, it can even cause frostbite on your fingers.
Overall, CO2 cartridges are a great tool for quick tire inflation, but I always weigh the convenience against the environmental and cost factors before I rely on them too heavily.
FAQ
Are all bike CO2 cartridges the same?
No, bike CO2 cartridges come in different sizes and designs, with variations in weight (e.g., 12g, 16g, 25g) and whether they are threaded or non-threaded.
How many bike tires will a CO2 cartridge fill?
A CO2 cartridge can typically fill one bike tire, depending on the tire size and the cartridge’s capacity.
How long do CO2 cartridges last?
An unopened CO2 cartridge can last indefinitely if stored properly, but over time, it may gradually lose pressure due to natural gas leakage. Once opened, the cartridge will only last until the gas is fully released during inflation.
Does it matter what CO2 cartridge you use?
Yes, it matters which CO2 cartridge you use, as the size and threading must match your inflator and tire requirements; using the wrong one can lead to under-inflation or even cause a tire blowout.
How to inflate a bike tire with a CO2 cartridge?
First, attach the inflator head to the valve stem of your tire. Then, insert or screw the CO2 cartridge into the inflator, depending on the type. Once secure, press the valve to release the gas and fill the tire to the desired pressure.
Do CO2 cartridges lose pressure over time?
Yes, CO2 cartridges can lose pressure over time, even if unopened, because they are typically sealed in metal containers, and CO2 molecules can slowly permeate through the metal. This natural leakage happens because CO2 molecules are smaller and more permeable than other gases, allowing them to escape over time.
Why does a CO2 cartridge get cold?
A CO2 cartridge gets cold because when the gas is released, it expands rapidly, causing a drop in temperature. Riders should be careful when handling the cartridge.
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