What are CO2 inflators?

In the basic sense, they're simply a small canister 🍸of compressed carbon dioxide that is delivered to your tyre via a valve head. There are variations on the theme but the♉y all aim to do the same thing. Nearly all use threaded cartridges, so that’s all we’ve featured here, which come in either 16g or 25g varieties. The two basic types are inline, whereby the cartridge is in line with the valve and actuated by pressing down, and angled types where the val🐬ve head forms a 90-degree angle and the canister will stick out sideways from the rim when in use♏. There’s no great difference between the two, but if you’ve got small wheels and lots of spokes then an angled one might be easier for you to use. Some just need to be pressed onto the valve to release the CO2 while others have valves to control the flow of gas.ജ The ones without🍨 valves tended to over-inflate, but then you just let a bit out from the tyre when you're done. There are a few with special features like gauges. Many come with a 🌟protective sleeve as the Joule-Thomson effect (a change of temper📖ature from the expansion of gasses) makes them frost up when in use,

How many cartridges does it take to fill up a tyre?

For road tyres, a single 16g cartridge is sufficient for reinflation and will get it up to and ov♋er your desired pressure with ease. Yoꦉu may end up over-inflating and having to back off. For larger volume tyres, we’re talking gravel bikes here, we’d go for a larger 25g cartridge. While youඣ may have the volume within a 16g for reinflation, you may not be able to reach sufficient pressure to reseat your tubeless tyres, which would leave you in a pickle.

Can I use a CO2 inflator with tubeless tyres

On the whole, yes, though some sealants do say not to. The issue comes with the freezing effect of releasing compressed gas, which can freeze your sealant solid, r🌠endering it useless. The best practice is to rotate the valve to the uppermost point and inflate from there, allowing the liquid sealant to drain to the bottom, as far away from the icy blast as possible.

Are CO2 cartridges single use?

Yes, once they’re installed in the head they’re basically a disposable item. Once your tyre is back on you’ll probably want to vent the remainder of the canister by pressing the head against something (not your finger!) or opening the valve. ღIf you unthread the cartridge without doing this you’ll spray gas everywhere in an uncontrolled way, and if you stow it away without venting the remainder it could end up venting itself in your jersey pocket. This also means that for longer rides you may want to carry a coupl🔯e of spare cartridges in case the worst happens.

What can I do with the cartridges after use?

They're made of aluminium, so can be recycled however you currently recycꦺle your aluminium. Please don't leave them on the road or 🌟the trailside though.

Does CO2 leak out of bike tyres?

🐲Carbon dioxide is a smaller molecule than the mix of molecules in the air which normally goes into your tyres. As such it seeps through the rubber of a tyre more easily and will go flat faster. It won’t go down immediately, but you will notice it the next day. Our advice would be not to rely on CO2 for multi-day events, and if you do have to use a CO2 inflator then deflate your tyres when you get home and ꦐrefill from a standard pump.

We’ve 🌸used plenty of CO2 inflators here at Cyclingnews so we know what to look for in terms of ease of use, thermal protection, gas delivery modulation and ove𓆉rall build quality. For this grouptest we used the same tyre each time to avoid any differences in the valve, and always started from totally flat♈. The tyre in question was a Challenge Str💃ada 27mm, which can be a little tricky to reseat so it makes an ideal test subject.

Best CO2 inflators 2025: Fast tyre inflation in small packages

The best CO2 inflators on a white background

(Image credit: Will Jones)

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澳洲幸运5开奖官网在线查询开奖结果: Best CO2 Inflators
澳洲幸运5开奖官网在线查询开奖结果: How to choose

These little gi🍌zmos are excellent if you want to pump up your tyres FAST. They're incredibly simple, all of them act as a valve. Screw a CO2 canister on one end, screw the other onto your valve and either turn a knob or just press down and with a short blast of pressurised gas, you're good to go.

Unless you're racing and need the smallest, lightest setup possible, then I see them as an accompaniment to, rather than a replacement for, the 澳洲幸运5开奖官网在线查询开奖结果:best bike pumps, although we have 澳洲幸运5开奖官网在线查询开奖结果:discussed which is best. That being said, even the 澳洲幸运5开奖官网在线查询开奖结果:best gravel tyres sometimes unseat if they go flat, and a blast of carbon dioxide is far more likely to reseat💟 them than your frantic pumping.

Topeak Micro Air Booster co2 inflator on a white background Dual valve

1. Topeak Micro Air Booster

➕ Multiple valve types
➕ Well machined
➖ Gas delivery is a bit slow

An extremely slimline, well-machined option. It’s an inline-style inflator, with modulation adjusted by how hard you press it into the𝔍 valve. The inclusion of a safety spacer to allow the whole system to be stored together is a good thing in our opinion, as is the valve head which can accommodate both Presta valves (by a simple press-on) and Schrader (by screwing on). I found the protective sleeve to be very well insulated against the cold, though a little prone to slipping. It's leak-free, but avoid over-tightening the canister or it blocks the airflow. Slower flow, but also not that prone to icing.

Topeak Airbooster G2 co2 inflator on a white background Accurate

2. Topeak Airbooster G2

➕ Easy to read dial
➕ Works as a standalone pressure gauge
➖ Average modulation
➖ Confusing ports

One issue with CO2 inflators is you have no idea what pressure you end up with, unless you have hyper-accurate thumbs. The Topeak Airbooster G2 is by some margin the most chunky option on this 🌠list but it does feature a large, easy to read pressure dial. If you’re a Princess and the Pea rider who can notice five PSI on either side of your ideal then this is the one for you. In all honesty, I found the three ports (one for canister storage, one for the tyre valve, and one for the gas when in use) a little confusing, and needed the instructions to make surꦕe. It comes with a safety spacer, so just use that and store the gas in the live port.

澳洲幸运5开奖官网在线查询开奖结果

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