They say two things in life are certain: death and taxes. For cyclists we’d add a third – punctures. The trick to reducing the hassle of flats is being prepared, so you can be riding again as quickly as possible, reducing the amount of time your mates stand around glaring at you. CO₂ inflators are a cyclist’s best friend in this regard.
A good CO₂ inflator can get you up to full pressure in seconds. For most riders, the little critters come out of our pockets fairly infrequently – but when they are produced, we want them to be quick, effective, and self-explanatory.
CO₂ inflators can come in a variety of forms: from simple, stand-alone chucks to units integrated into multitools or mini pumps. We'll start by taking you through the best units we've had on test, and take a dive into the pros, cons, and everything you need to know about CO₂ inflators just after that.
The best CO₂ inflators
CO₂ chucks
Chucks | Multitools | Pumps
Sometimes it's the simpler products that are harder to get right. With fewer aspects and parts, the onus becomes proportionally greater to get the execution spot on. Pleasingly, though, Muc-Off has done an excellent job with its Road Inflator Kit.
First is the size: it's pretty compact compared to other simple, inflator chucks. Some designs out there are smaller still, but they lack the other features of this Muc-Off inflator – such as the sheer ease of use.
The moderately wide metal head makes it a doddle to screw the CO₂ cartridges in and, once screwed all the way in, there's no notable leaking from anywhere on the unit. You could have it primed and ready to go ahead of an important, unsupported race or event.
Thanks to the double threading, the chuck can be simply attached to both Schrader and Presta valves without any modifications. On the back of the inflator, there's a button for controlling the flow of CO₂, from a fast stream to as slow a trickle as you like.
Perhaps because of the thickness of the metal head, I didn't find it got so cold when using the inflator and didn't require gloves or a foam sleeve on the cartridge to act as a barrier. Nevertheless, Muc-Off does supply a Neoprene sleeve with the unit.
It's one of those tools that you don't give a second thought when you're using it because it just simply works, straightforwardly and without hassle.
Topeak has one of the biggest ranges of pumps and CO₂ inflators on the market. This Micro Airbooster fills a similar role to Muc-Off's Road Inflator Kit, but goes about it with quite a different design.
It's much longer and thinner for one thing, which might suit certain people's packing requirements better. A really neat little feature is the safety spacer that allows you to screw a CO₂ cartridge into the unit without the chance of accidently piercing it – although this does make the whole package really quite long.
Like the Muc-Off inflator, the chuck can be used with both Schrader and Presta valves without any modifications or adjustments. The flow can also be controlled by just how hard you press the chuck onto the valve.
But herein lies the problem for the Micro Airbooster. Although Topeak supplies a silicone sleeve, gripping by the sides to force it the unit onto the valve means the sleeve slowly starts to slip.
What's really needed is pushing the unit onto the valve from the bottom – but that's one of the small sections that isn't covered by the gripper.
It's not the end of the world: you could add some tape to the cartridge or, if you're wearing gloves, it might simply not be a problem. The Chuck does work well in other respects. But it's a bit of extra faff and a less clean execution than the Muc-Off inflator.
The Lifeline CNC CO₂ Inflator isn't quite a sixth of the price Muc-Off's inflator sells for, but it isn't far off. With such a gulf in cost, it can be hard to make a meaningful comparison – is the experience with other inflators really 10 times better? Still, I'll give it a try.
The chuck has a number of points going for it: it's a very compact unit and the plastic screw/sleeve for piercing the cartridges provides an integrated insulation solution that removes the need for CO₂ cartridge sleeves.
But with that said, the Lifeline CNC CO₂ Inflator isn't very user friendly when it comes to actually using it for its primary purpose.
Whereas other units, such as the Topeak Micro Airbooster just need the cartridge screwed in before being pressed on the valve and away you go, the Lifeline CNC CO₂ Inflator requires you to first screw the plastic screw/sleeve bit in, then screw the CO₂ cartridge into the plastic screw/sleeve (while taking care not to end up overtightening the plastic screw/sleeve against the body of the chuck).
Finally, unscrew the plastic screw/sleeve and the gas will be released. It's not a simple process and it's easy to get a bit wrong and end up overtightening different parts. I'd definitely recommend using it at home before using it in anger at the road-side.
But then again, despite the frustrating experience, it does still work and it is just so much cheaper than the 'top-end' CO₂ chucks. Just think about all the cartridges you'd be able to buy. On balance, I think it's still worth an inclusion, considering the price point, but do make the choice with open eyes.
CO₂ mutitools
Chucks | Multitools | Pumps
Multi-tools have a difficult balance to tread. You want them to be compact and pack a lot of different functions, but the more compact multi-faceted they are, the less practical they become for actually doing those jobs.
The LifeLine Pro 18-In-1 Multi-Tool sits at one end of that spectrum. In addition to its integrated CO₂ inflator, it boasts a chain tool, spoke keys, various Allen and Torx keys and both flat and cross head screwdrivers – but all of these are quite stubby and difficult to use.
It's great as a minimalist 'just-in-case' tool that 's there if you need, but not expected to be used. But if I was going on holiday, I would bring another set for the actual packing and building of my bike.
But onto how it performs as an inflator. It couldn't be more simple: screw the cartridge in until you feel the slightest resistance, squeeze the chuck onto the valve, then twist through the final bit and let the gas flow out.
There's no scope for controlling the flow, but it doesn't come out at lightening speed, so you'd be able to take it off before over inflating a narrow tyre. It's still reasonably fast, but it might struggle reseating the most stubborn of beads on tubeless tyres.
As it takes a second or two for cartridges to start freezing up and, as the tool itself is quite large, you can quite easily hold it on the valve without worrying about your fingers getting cold.
Condor's multitool with with CO₂ inflator does have a well-thought out arrangement of tools. Usually for a multitool (but great considering their increasing presence) there are three Torx heads as well as Allen keys going up to 8mm. It also boasts two different sizes of both cross head and flat head screwdrivers.
Although good at screwing (careful...), Condor's multitool does lack the chain and spoke tools of the Lifeline model. But then it is a little more compact still and the tools are more usable – so horses for courses.
It's a promising start, but the CO₂ chuck lets it down. The design is very straightforward: simply screw the cartridge most of the way on, then screw the chuck onto the valve. Finally, finish off screwing the cartridge until the seal is broken and the gas flows out.
But despite the knurling on the chuck, I couldn't gain enough purchase to screw in the cartridge sufficiently tightly to pierce the seal. I ended up using a set of pliers to finish the job – which does defeat the point of a small, lightweight multitool.
It's a shame as the tool is very neat in a lot of other ways. If it didn't have the CO₂ chuck and was a little cheaper, I'd recommend it as a solidly performing standard multitool.
CO₂ pumps
Chucks | Multitools | Pumps
The Crankbrothers Klic HP Gauge + CO₂ mini pump packs a lot of cool features, even if they aren't immediately obvious.
To use it as a pump, first you have to twist the handle 90 degrees which opens up access to the hose. Then, the hose attaches to the port at the other end of the pump, with all that's left to do being attaching it to the valve.
The hose shows your tyre pressure in 10 psi / 1 bar increments and has a reversible chuck that allows you use it with both Schrader and Presta valves.
The CO₂ part of the pump is pretty much completely separate, being a chuck that screws into one end of the handle. It's a very simple design, like that of the multitools, with no flow control and only working with Presta valves.
In all, it's a very neat system and the pump is quite effective – although the stroke is quite short and it only inflates on the downstroke, the chamber must be reasonably large as it got up to 22psi with a set of 40mm gravel tyres in just 100 strokes (about a minute of pumping).
The only critism really to make is that the whole unit is quite bulky. It's not the sort of thing you'd really want to be attaching to a race-y road bike. Functionally, though, it really does the job well.
Topeak's Hybridrocket HP is a more slimmed down than Crankbrothers Klic HP Gauge + CO₂ , but it still packs a lot of functionality.
The pump has an integrated hose that works with both Presta and Schrader valves, while the CO₂ system at the other end also works with both systems – unlike the Crankbrothers pump. A very thoughtful touch is the unit's rubber coating, which insulates your hands from the cold.
The two areas that Topeak's Hybridrocket HP does lose out on are the stroke volume (about half that of the Klic HP Gauge + CO₂) and the pressure gauge. On the other hand, beyond the slimmer size and ability to work with more valve types, the Topeak pump also integrates storage for up to two CO₂ cartridges – which is a neat extra touch.
There are those diametrically opposed to any pump being attached to a road bike, save for the sort that match the tubetube in length and sit just underneath. Even then, only if the bike is also sporting mudguards. But aside from this hardcore of arch-traditionalists, the size of the Hybridrocket HP is small enough not to look out of place on an endurance bike.
The size of the XLab Tire Mate is barely larger than a CO₂ cartridge itself and fulfils a very useful role.
It's always good practise to bring a pump. CO₂ might save time, but you only get so many tries and getting stranded because you've run out is one of the most frustrating experiences you can put yourself through.
But pumps can be bulky – and those that aren't don't tend to pump particularly well. You could bring both a small pump and a CO₂ chuck, but by that point you almost might as well just bring a bigger and better pump.
By combining a pump and CO₂ inflator in one diminutive package – it literally fits in a saddle bag – you get the best of both worlds. A low pack weight and volume, but with a backup if you run out of cartridges.
There are some compromises, though. The cartridges attach and are primed in the same way as with Lifeline's CNC CO₂ Inflator – that is to say, with a lot of scope for faff. You had also better hope that you don't ever run out of cartridges, as the volume of air that is moved with each pump is truly miniscule.
So it's very much a 'just-in-case' tool, but if you're not expecting an issue and just want a that little bit of extra insurance, it does impart a minimal impact on your ride.
CO₂ inflators: everything you need to know
What is a CO₂ inflator?
CO₂ inflators consist (broadly) of two parts: a CO₂ canister (aka cartridge) which contains the compressed gas and some form of chuck for attaching to the tyre valve. Generally, you simply screw the canister in and the gas is released, inflating the tyre in seconds.
For road and gravel tyres, CO₂ cartridges generally hold about 16g of the gas. MTB models are about 25g. To put that in perspective, the average petrol car on the road in the UK emits 180g of CO₂ every kilometre.
A few years ago, you'd rarely see a rider out without a mini-pump, but now you see a lot of smaller loads stuffed into jersey pockets, in the shape of the CO2 inflator and canisters. But there are pros and cons of both options.
CO2 inflators and canisters pros and cons:
| Pros | Cons |
|---|---|
| Lightweight and low bulk | Each canister is one use |
| Gets you up to pressure in seconds | Can be tricky to get the desired PSI |
| The quick blast of pressure can reseat a tubeless tyre | Not reusable and not so eco friendly |
Mini pump pros and cons:
| Pros | Cons |
|---|---|
| Endless possibilities for tyre inflation, a pump never runs out | Your arms do... pumping to even 80 PSI can take some effort |
| It's easer to hit the right pressures | Pumps are bulkier to carry |
One approach is to carry CO2 which will get you quickly up to pressure when required, but to have a back-up pump as well. However, those who don't like the feel of too much kit jangling in their pockets may choose to chance it with CO2 alone.
What to look for
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Wrap that canister
The metal canister will get to freezing point as it quickly discharges its gas — if you have bare fingers they’ll get stuck to it causing severe discomfort! Either wear long finger gloves or better still put some sort of sock over it — it’ll serve the double purpose of stopping the metal bottle rattling in your seat pack. Notice that some of these kits cover the canister as part of the design.
Reduced bulk
Like your bike you’ll be taking your chosen CO2 pump with you on every ride. Not only will it take up vital space in your saddlebag or pocket, but you’ll also have to drag the weight up and down every hill you ride. It therefore makes sense to get one that’s as light and small as your wallet will allow.
Ease of use
It sounds daft but you need to be able to use the pump quickly and easily so it needs to be quick and easy to use. When you’re cold and tired — the most likely time you’ll get a flat — you don’t want to spend time faffing with a complicated mechanism. A valve or push fit are therefore the best options.
Pressure tap
Some CO2 canisters come with an on/off valve so you can apply just the right amount of pressure. These are usually a little bit more expensive, but they save you blowing a canister with every use as you can save some if you like, and it also means you can add that little bit of air before you fit the tyre, reducing the chance of pinch punctures.
Threaded/non-threaded canisters
All CO2 canisters are not created the same. Some have a threaded tip, whilst others are smooth. Neither is right or wrong, but when buying a new inflator, make sure you're getting compatible canisters.
