Fast riders prefer CO2 inflators when it comes to fixing a flat tire trailside. They’re the quickest way to put air in a tire short of packing a compressor and a really long extension cord on your next ride. They’re not the cheapest method, as each cartridge typically sells for a few bucks and only houses enough to inflate one tire, but if you’ve ever experienced arm fatigue when using an under- powered mini pump to inflate a tire, you’ll appreciate the luxury and speed a good CO2 system provides. Unfortunately, early inflators were plagued by cheap plastic construction that inevitably caused a frustrating hissing of all the gas escaping with an early release. The good news is that the inflators in this test are head and shoulders above the old-school ones. In our test, not a single CO2 cartridge went to waste. After months of testing, we put together a list of CO2 inflators we’d be happy to have on the trail with us when faced with a flat tire.
CO2 SHOOTOUT QUICK FACTS
—CO2 cartridges come in two basic varieties: threaded and non-threaded. Some inflators are specifically designed to work with one type, while others can work with both.
—Cartridge size varies. The small cartridges you can buy in bulk at a sporting-goods store are typically 12-gram unthreaded and often don’t provide enough gas to fill a mountain bike tire. Sixteen-gram cartridges will work for most small-volume XC tires, and 25- or 30-gram cartridges can handle larger air volumes and 29er tires.
—All CO2 inflators get extremely cold when the gas is released to the point where you can freeze the valve or even your skin. Many inflators have features that are designed to keep your hands insulated.
—CO2 gas is not compatible with most sealants because it comes out of the cartridge so cold. This can freeze the sealant, rendering it unable to fix a puncture. If you’re fixing a flat trailside with CO2, it’s best to install a tube.
—Cartridges are single-use, as once the cartridge is punctured, the pressure will slowly leak from most any regulator. Since these are single-use, we highly recommend recycling the steel cartridges to reduce waste.
—All inflators in this test are compatible with both Schrader and Presta valves.
—CO2 regulators vary in complexity— from super-stripped down and simple to fancy and loaded with features. We are testing some of each in this shootout. Most companies make several models, which means the rider can choose how many features are included.
—All weights are for the inflator only with no cartridge.
Weight: 22 grams
Cartridge: Threaded only
The AirBooster is a CNC-machined inflator that’s very compact and lightweight and designed to work with any threaded cartridge. It features a head that regulates the flow of CO2 to the tire, which means the gas doesn’t escape in one quick burst. The flow regulator feature is easy to use. The more you depress the valve, the more gas it releases. The AirBooster also has a nifty second threaded spot to store your unused cartridge, ensuring it won’t puncture before you need it. To use it, simply remove the dust cover and move the full cartridge to the hot spot, puncture and inflate. We were impressed with the lack of leaking, probably due to the snug fit of the head to the valve.
• Compact design
• Flow of gas is very easy to control
• Nifty storage spot keeps fresh cartridges from being punctured
• No insulation from the icy-cold cartridge
Weight: 42 grams
Cartridge: Threaded, up to 20 grams only
The Sterling has a relatively compact design that uses a simple spring-loaded head and integrated frost guards that run down the sides of the cartridge. Crankbrothers builds all of its products with a sleek aesthetic, and the Sterling is no exception. The head has a fairly stiff spring that works like an on/off switch that bursts pressure, but it fit the valve well and did not leak. The freeze guards are a nice fea- ture as long as you remember to use them, as the exposed cartridge can still freeze your hands if you’re not careful. The freeze guards’ shape prevents any oversized car- tridges from threading in, so this isn’t the right inflator for the fat bike, plus-sized or big 29er crowd; however, it’s simple, easy to use, and built very well.
• Easy-to-use head
• Freeze guards keep your hands from freezing
• Cannot use oversized cartridges
Weight: 24 grams
Cartridge: Any size threaded
The Air Rush is a new CO2 inflator from Bontrager that features a simple CNC construction with a plastic knurled knob on top to control gas flow. It comes with a foam sleeve on the included 16-gram cartridge and a nifty rubber piece on the head to help grip the tool. The head works well and mates to a Presta valve without sticking or leaking. The knob on top precisely controls both flow and pressure, although it requires two hands to do so. At 24 grams, it’s light-weight and simple with enough features to make it one of our favorites in the bunch.
• Super-precise dial to control flow
• Lightweight and simple with quality construction
• Requires two hands to use
Weight: 47 grams
Cartridge: Threaded, any size
SKS is a pump and fender company that takes some of the most mundane accessories and adds German engineering to make them great. The Airbuster is a compact CO2 inflator that can use any size threaded cartridge and uses a threaded open-and-close valve on the top to control airflow. You’d think the button on the back of the head was the air control, but it’s not. That flap is designed to transport an unpunctured cartridge without accidentally releasing the CO2. The Airbuster works by pushing the head onto the valve and the turning the knob on top to the open position to control the flow. This is the most controlled-feeling inflator in the bunch. In fact, when using some of the larger cartridges to top off a tire, we were able to close the valve and actually save half a cartridge for another use, something that none of the other inflators can claim. The Airbuster is not the easiest to use, as it requires two hands and has a stiff valve head that doesn’t seem to like to go on or come off a Presta valve, but the quality construction and ability to save half a cartridge are appealing.
• Best control of the CO2 flow
• Closed position can save half a cartridge for another day
• Requires two hands to use
• Stiff head sticks to Presta valves
Weight: 63 grams
Cartridge: Threaded or non-threaded
The Proflate Elite is Genuine Innovations’ most precise inflator and is able to work with either threaded or non-threaded cartridges. With the threaded option, any cartridge will work. When using the plastic sleeve for unthreaded ones, the inflator can use anything up to 16 grams. The inflator has a bit of a MacGyver feel to it with two triggers. The first one opens the dust cover, and the second one releases the CO2. While not the lightest in the test, nor the most svelte-looking, it works flawlessly and gives the inflator a very controlled feeling. The dust cover is also a nice touch, especially for those who ride in adverse conditions and want to mount the inflator to a bottle mount with the included bracket. As a bonus, the inflator’s complete coverage of the cartridge when used with a non-threaded cartridge protects your hand from freezing. The head also has a nice fit that is easy to squeeze onto the valve and doesn’t leak pressure during inflation.
• Compatible with most any cartridge
• Easy-to-use trigger makes precise psi easy
• Plastic construction doesn’t feel as sturdy as others in the test
Weight: 13 grams
Cartridge: Any size threaded
This is by far the most stripped-down inflator in the bunch. To use, simply install the head onto the valve and thread the cartridge in. Then, back it off a quarter-turn to release the pressure. There is little regulator function to control the flow, so you have to be ready for the burst of pressure when you let it loose. It’s the lightest and least expensive inflator, and almost nothing can go wrong unless you unscrew it too soon and blow your last cartridge. When used properly, the Twin Speed Drive flows air into the tire quickly and efficiently. Lezyne even includes a neoprene cover to keep your hands from freezing—and you’re going to need it. The pressure comes out quickly and ices over the cartridge in less than a couple seconds. Lezyne makes several CO2 heads that come with regulators, much like the other ones in the test; however, the simplicity of this inflator is a big draw. It will appeal to riders looking for an elegant and lightweight solution to inflation.
• Super light and simple
• No moving parts to fail
• Easiest to blow a cartridge with if unfamiliar with function
Weight: 243 grams
Cartridge: Any size threaded
The Park MT-40 is a different kind of inflator, as it’s attached to a multi-tool. The inflator itself is as simple as it gets, with no buttons, valves or ways to control the flow. That said, it would be a lifesaver in a pinch. The small black barrel is stored on a threaded piece on the tool. Simply remove it from its place, spin it onto the cartridge and tighten it down. Then, back it off to begin the flow of CO2. While certainly not the most ergonomic or most precise for controlling flow, the inflator works well enough to use for more than just emergencies. The only issue is that with no insulation, it must be used with a gloved hand or you will freeze your fingers. The bonus, though, is that the MT-40 also has enough tools to handle nearly any trailside mechanical that might arise.
• Comes with enough tools to fix anything
• Perfect doohickey to have in an emergency
• Small, detachable inflator may be easy to lose if not attached to multi-tool
• No insulation; must be used with gloves
THERE ARE SO MANY WAYS TO GET MOUNTAIN BIKE ACTION
Mountain Bike Action is a monthly magazine devoted to all things mountain biking (yes, that’s 12 times a year because we never take a month off of mountain biking). It has been around since 1986 and we’re still having fun. Start a subscription by clicking here or calling (800) 767-0345.
Contact us via email at email@example.com