It wasn’t long ago that frame manufacturers wouldn’t dream of releasing a frame without mounts for a pump. Now the vast majority of us do our roadside inflating with a C02 cartridge and a small inflator head. It’s fast, convenient, and far less bulky.
Of course, C02 systems require that you buy a consumable item: C02 cartridges. Once they’re spent, they’re trash. And it’s a one-off system, so if you run out of cartridges out on your ride, chances are you’ll wish you were carrying a small pump with you.
For unsupported racers who want to change flats quickly during races or training rides, C02 is hard to beat. And if you just don’t want a pump cluttering up your pocket, you can opt for these diminutive systems that fit in your seat bag.
While any old inflator will do in a pinch, the ones you can rely on ride after ride all have a few things in common, like tough construction, light weight, and easy inflation whether you run Presta or Schrader valves. The best systems are designed to help you hold the head or cartridge, even when it freezes during the inflation process. For $35 or less, you can choose an inflator system that will become a staple of your riding gear for years to come.
Choose your CO2 inflator based on these four factors:
Head construction. Plastic is light and inexpensive, but not especially durable. Aluminum combines low weight and durability that’s ideal for an inflator head, but it’s likely to cost a bit more. Of course, you’re also more likely to get many years of service from it.
Inflation process. The three most common inflation processes are: Press to inflate; twist the cartridge to inflate; and twist a control knob to inflate. All three work well, though the cartridge twisting method generally means once the cartridge is pierced, you’ll need to empty it completely. A control knob allows you to tailor your tire pressure, and a press-to-inflate system is the quickest and easiest method. Racers should choose the latter; PSI weenies should go with a control knob system.
Size and weight. Okay, they’re all pretty light. But if you’re looking for the absolute lightest for your featherweight climber’s bike, it’s certainly possible to do so. Just don’t sacrifice usability to save a few grams; you’ll regret it when you’re on the side of the road with a flat. But if your seat bag is tight on space, choosing your inflator head based on size is a legitimate concern.
Ease of handling. A lot of inflators now include some sort of cartridge sleeve to protect your fingers from frost on the C02 cartridge during the inflation process. This ensures a more solid grip on the system as you inflate. For systems that don’t include such a sleeve, look carefully at the head’s ergonomics and figure out how you will hold it while you’re inflating to avoid the extreme cold of the CO2 cartridge.
$30 (Includes rubber sleeve)
Weight: 23 grams (head only)
While it’s on the pricey side for an inflator, Topeak’s Airbooster features all-metal construction. It also includes a rubber sleeve to protect your digits from cold cartridges. And it’s impressively light for its size.
The push-to-inflate system activates quickly and holds air when you remove the head from the valve. There’s a rubber gasket on the top and back of the head, which makes for a great place to put your hand to avoid the frost. But the actual function of this gasket is to protect the threaded cartridge interface. This seems like a solution to a problem that doesn’t really exist.
The ‘storage’ end of the Airbooster is a nice touch: You can screw your cartridge in there tightly so everything’s connected as one unit, without actually piercing the cartridge. When you’re ready to inflate, just unscrew the cartridge from that end and screw it into the opposite end.
The biggest drawback to this otherwise excellent inflator is its awkward shape. No, it’s not awkward to hold; rather, it’s awkward for storage in your seat bag. If you’re tight on space, this might be a bit of a headache for you. Otherwise, Topeak has designed a solid unit with enough nice features to make it a win.
Genuine Innovations Airchuck+
$30 (includes one 20-gram CO2 cartridge)
Weight: 39 grams
The Airchuck chucks the cartridge sleeve and instead shrouds the aluminum head in a plastic cover to protect your digits from frost. It provides a big gripping surface too, but it does add bulk and weight to the unit. If you’re tight on space in your saddle bag, this might not be the best choice. Opt instead for the diminutive Airchuck.
This is one of the easiest inflators to use and hold. Just push to inflate, then pull off. The head is spring-loaded so you can feel when the system engages and disengages. Everything about this inflator screams burly.
It holds air once you remove the unit from your valve stem, so you could top your other tire with the same cartridge if you want. As long as you’re not short on space in your bag or too concerned with weight, The Airchuck+ shines.
Editor’s pick: Portland Design Works Tiny Object
$25 (includes leather sleeve)
Weight: 17 grams (head only)
It’s tiny, lightweight, snazzy, and it comes with a sweet leather cartridge sleeve. Portland Design Works has created an excellent inflator for the weight weenies among us who don’t want to take up much space in our saddle bags. The full alloy construction makes this piece feel rugged, like a real tool rather than a throwaway.
It’s also easy to regulate the flow of air so you can customize your air pressure — well, customize it as much as you can without a gauge anyway. You can open the knob on the top a lot to release a big burst of air or just a little to top off your tires. You can turn it with one hand, but it’s easier with two. This is an easy favorite for road, mountain, and gravel use.
Pro (Shimano) Micro Inflator
$20 (includes one 16 gram C02 cartridge)
Weight: 22 grams (head only)
The Micro Inflator’s plastic construction keeps the weight down to a slender 22 grams, though this unit doesn’t feel as solidly built as it’s aluminum competitors. If you’re after a light and inexpensive inflator, this is a decent option that includes a rubber cartridge sleeve so your fingers don’t freeze as the cartridge empties.
Operating the inflator is easy: Screw in the cartridge and push on the spring-loaded head to inflate. You can inflate in small bursts to top off your tire pressure, too. It works on both Presta and Schrader valves (though you’ll need to screw the unit onto a Schrader valve).
One complaint: Once we removed the inflator from our valve, it continued to leak air from the cartridge. This is really only a problem if you’re trying to inflate more than one tire with a single cartridge, or if you try to remove the inflator and put it back on to top off your tire. Still, for a fair price and low weight, the Micro Inflator is a good choice for budget-conscious riders.