Just say not to CO2
It’s winter in the Northern Hemisphere. That means scarves, varying states of compliance with New Year’s resolutions, and an excessive number of tire punctures. Don’t get me wrong, it’s not all bad. I really like scarves, they look pretty dashing and help me keep warm when I’m by the side of the road inflating my tire as cars chortle past me in their happy little smug cocoons. It seems that at this time of year, when it’s time to pull the road bike out from the shed, call your friends, and start logging miles towards the spring, barely a single ride goes by without someone getting a puncture.
No cyclist likes punctures. No cyclist likes fixing punctures. So it’s very tempting to do whatever you can to get yourself back on the road again. I understand that desire, it’s why I run tires my friends often refer to as boat anchors and use approximately a gallon of sealant to boot. I am also lighting fast with a tubeless plug, which can often make the difference between re-inflating and just topping off a tire. But one thing I don’t do, won’t do, and hope never to do, is use canisters of CO2 on a training ride.
CO2, my friends, should be reserved strictly for race days, and even then, only races where you really want to win or set a personal best time. I know, it saves you a minute or two when you fix your punctures, but I’m here to tell you it’s not worth it. Sure, it’s easier than flailing away with a mini pump, but you’re a cyclist, you could do with an arm workout anyway. So get a proper frame pump and get to work. At least you won’t get cold that way.
Still not convinced that you need to ditch the CO2 and use your pump to get pumped? Let me lay out my case for you. Firstly, CO2 is hugely wasteful. Every time you puncture you are throwing away a 50g steel container. Genuine Innovations website notes that the cartridges can be recycled, but this process takes energy, as does shipping around a product which really doesn’t need to exist. A metric ton of cartridges (20,000 50g cartridges), shipped by road, generate 60-150g of CO2 per mile, if we ship those cartridges coast to coast (estimating a distance of 3,000 miles and using a conservative estimate of 100g CO2 per mile) we generate 300,000g of CO2. So even if the cartridges use captured emissions (which they do in the case of Genuine Innovations), a relatively conservative shipping estimate (which assumes they are made in the USA and travel across once).
CO2 is also not that efficient in terms of performance, either. My Lezyne Road Drive pump weighs 82g including the Duct Tape I have wrapped around it for emergencies. The nearest CO2 I could find weighs 50g, so unless you only carry one CO2 cartridge you’ll be carrying more weight. Okay, so it takes longer to inflate a tire with a pump, but my 200g frame pump can inflate a road tire in under 90 seconds, and I have never scared off a dog with a CO2, or frozen my hand to a frame pump.
Once I am done using the pump, I put it back on my bike and forget about it. I don’t have to remember to drop in at the bike shop and replace it, at a cost of several dollars, with another hunk of steel that will fill one tire, for one day, before I have to re-inflate it anyway because the CO2 leaks out of the tube much faster than air will. Nor do the TSA steal my frame pump when I fly and leave me at an important event with no way to fix a puncture, or require dashing around Reykjavik looking for CO2 as some of my friends did before a gravel race in Iceland this year.
My pump also provides enough air for multiple flat repairs. Sure, if you only ride on nice roads for a short amount of time it might seem unlikely that you’ll get more than one flat. But visit Southern California in goathead season, or the UK when hedges are being trimmed, you’ll soon come to appreciate the security that comes from carrying a pump and a patch kit on all our rides. Even if you were to somehow carry half a dozen CO2s, I have found a much higher rate of failure with inflator chucks than pumps (and very few of them are rebuildable, unlike my Lezyne pump).
There is a time and a place for CO2 cartridges, and that is in off-road races. But even in competitive gravel events, I still carry a pump. I think I used one CO2 at Dirty Kanza, but the thirty seconds it saved me were pretty meaningless after a dozen hours of chasing the guys who rode away from me in the five or more minutes I spent cramming Dynaplugs into a terminally-slashed tire. I used my pump the next four times I need air. I will accept that a deft tire plug and CO2 fix could see you off your bike for less than a minute, and possibly back with the group you were in. But any time the tire comes off the rim your race is over, and when you’re not racing there’s really no excuse for all that waste.
There is already enough waste associated with our collective bicycle habit. Between gel wrappers, discarded inner tubes, broken carbon parts and overpackaged everything, our love of the outdoors sometimes harms the places we like to play.
In the case of CO2 cartridges, the negligible practical benefits seem to be far outweighed by the practical costs. And besides, carrying a proper frame pump and two tubes on your bike lets people know that you’re out for a long day, and if you get out for a few long days this winter you’ll be saving time from faster legs, not faster puncture changes.