CO2 cartridges can be a quick and convenient way to get back on the road after a flat, but there are a few things to look out for to make sure you don’t accidentally get stranded.
Make sure you know how to use your specific CO2 inflator. There are many different CO2 inflator designs that work in very different ways. Some of them have a trigger that lets you release a little bit of CO2 at a time. Some of them are spring loaded so they can stop and go, and a few of them only give you one shot to get things right, because all the CO2 comes out at once. Try yours out at least once at home so that you understand how it works. If someone lends you one during a ride, it isn’t foolish to ask how that specific device works before you try to fill up your tire.
Make sure your tube is fully inside the tire and not sticking out from the rim somewhere. There’s nothing worse than fixing a flat, adding CO2 and then giving yourself another instant flat by pinching the tube between the rim and the tire bead.
Make sure you have the right kind of CO2 cartridge to match your inflator. There are threaded and non threaded cartridges. If you accidentally buy the wrong kind that doesn’t match your inflator and don’t notice until you have a flat, you could be out of luck.
If you are riding tubeless with sealant, put the valve up at 12 o’clock as you inflate. The ultra cold CO2 that comes from the cartridge can cause the latex to coagulate so that you won’t have any left to seal the tire. If the valve is at the top, then the sealant will pool at the bottom of the tire and you’re less likely to have this problem.
When you get home, deflate the tire and pump up with a regular pump. CO2 seeps out of latex and butyl tubes faster than air does. So if you forget to do this, you’ll probably notice before your next ride that the tire seems much lower than usual. It’s not necessarily because you didn’t fix the flat correctly — it’s because the CO2 seeped out.
Readers, what other CO2 problems should riders look out for?