Jim’s Tech Talk
By Jim Langley
Obviously, CO2 inflators are wildly popular and fascinating, too! Believe it or not, last week’s Tech Talk about these tiny ride-savers – which was actually an article from 2017 (because I was away RVing and riding in beautiful Half Moon Bay, California) – now has over 50 comments old and new.
Thanks so much for sharing your tips and advice. Since these handy almost-instant inflators are so common, let’s look at some of your suggestions and thoughts. I’ll weigh in where it might add value.
Avoiding tire Blow-off
First, rereading the original article, I realized that I should provide a tip for avoiding tire blow-off when using CO2 devices. I wrote,
“Another issue is that the CO2’s speedy inflation can blow a tire off the rim if the tire or tube wasn’t installed correctly. For example, if you rush to fix a flat you might not quite seat the tire on the rim. A common mistake is to have a section of tube trapped beneath the tire bead.”
What I want to add is HOW to avoid a tube getting trapped beneath the bead. The trick is to always inflate tubes so that they’re round and stay out from under the tire (a flat tube easily finds its way underneath). To get just the right amount of air in the tube to round it out is easy with Presta valves.
Just unscrew the tip and jiggle it to make sure it’s open. Then as if inflating a balloon, put your lips on the valve and blow until the tube is fully formed and there are no wrinkles. Be sure to tighten the tip of the valve so that you don’t hit it and mistakenly let the air out during tire/tube installation, which will allow the soft, almost flat tube to sneak under the tire. With Schrader valves, use a pump to round out the tube.
It’s much easier to avoid catching rounded tubes under the tire beads because there isn’t much clearance.
CO2 Inflator Recommendations
Since you might be in the market for one, let’s start with your favorite CO2 inflators.
Several of you like the Genuine Innovations Ultraflate ($18.49), which holds cartridges in a case for comfort and has a trigger control for on/off and easy inflation. https://amzn.to/39XBGY1.
Reader John Tonetti says Silca’s Eolo III CO2 Regulator is “awesome.” https://amzn.to/38R3q05 I can see why he likes it. It’s the type that’s tiny and simply screws on the end of cartridges. Plus, it has, according to the company, “an ultra-precise spool valve design with light action spring” for precise control of the air into the tire. And it’s made of 6063 aluminum and stainless steel – no plastic – with a hardened tool steel puncture pin that’ll open cartridges with ease for many years.
One of the issues with CO2 inflators that multiple roadies commented on is getting stranded because you have an issue with a cartridge or connection and can’t inflate the tire. To avoid that possibility, a reader named Fred was kind enough to recommend a hybrid model (functions both as a pump and CO2 inflator), Lezyne’s Pressure Drive CFH https://amzn.to/38TIJkj $49.99.
Fred writes, “The reason I suggest that one is because most minis cannot get to 75 psi. I have Lezyne’s Road Drive and it will get past 120 and do it in less strokes than any mini pump I’ve used trying to get to 75 or so! So I have to assume that the CFH should perform similarly.”
Russ and NJgreyhead gave a thumbs up to Planet Bike’s Red Zeppelin inflator, which allows controlling the flow of CO2 and is covered with a foam sleeve for insulation ($20) https://amzn.to/2HZh99H
Several CO2 users explained that the gas seeps out of tubes more quickly than tires pumped with air. And, even more so when you are riding with latex tubes. John, who told us about the Silca Regulator pump suggests carrying a butyl tube and installing it if you flat. Then he just changes back to the latex when he gets home.
Kerry Irons explained why tubes lose CO2 more quickly than air. “Both butyl and latex tubes are more permeable to CO2 than to air (nitrogen and oxygen) and this is why tires go soft faster with a CO2 change compared to those pumped up with air.” Thanks, Kerry!
Beware Removable Valve Cores
Tom Wojcik points out that some Presta valves have removable cores. The core is the mechanism at the top of the valve. If it’s removable, you’ll be able to see two wrench flats on either side at the very top.
Removable valve cores can be a nice feature should you ever have one go bad, since you can replace it rather than the whole tube. But, Tom has seen removable cores unscrew when removing a CO2 inflator. And when that happens you immediately lose all the CO2 from the tire – “deflating the tire as fast as the CO2 cartridge inflated it!”
To prevent the frustration, check to find out if you have removable valve cores. If so, put a special valve core wrench on them or grip them with pliers and turn clockwise gently to make sure they are not loose. Careful. You don’t want to damage the tip of the valve or crush it. Just hold on to the wrench flats. See photo.
Protection from the Cold of CO2
An anonymous reader commented that using CO2 pumps and holding them by the cartridge is even worse in the rain. He says that one of his pals was left with large blisters on his hands from it! His advice was to wrap a glove around the cartridge or other insulator.
Charlie Johnson likes to cut a piece of inner tube and slip it over. He says the tube also keeps the cartridges from knocking together in your saddle bag or jersey pocket, too.
While David K wraps a spare CO2 cartridge in duct tape, which keeps it from clinking against the 2nd cartridge plus the tape comes in handy for numerous quick repairs like making a temporary tire boot, tying off broken spokes, etc.
Advantages of CO2
To those who prefer to stick with pumps rather than CO2 inflators, Jim quipped, I don’t know.. After changing a tube in the dark when it’s cold, raining and you’ve been riding for 18 hours – being able to speedily inflate a tire without any pumping can be pretty appealing (I do carry a pump for backup).
“HLM” agrees. He wrote, I now have tubeless with sealant and a few Stan’s Dart units (the best way to seal a tubeless tire with a large hole https://amzn.to/2SWed3S ). I carry a CO2 inflator and a pump – anything to get back on the road again, the sooner and easier/the better.
Put the Valve High when Inflating Tires with Sealant Inside
“HLM” also wrote, “One thing not mentioned is that when using CO2 to fill tubeless tires that have tire sealant in them, you should make sure the tire valve is in the 12 o’clock position for a few minutes to allow the sealant time to settle in the 6 o’clock position and apply the CO2 slowly, to reduce the freeze affect. This way you won’t have to worry (as much) about the sealant beading up and losing its functionality.”
My thoughts: I’m not sure the CO2 or cold will make sealant bead up or lose its functionality. I think sealant should be fairly temperature-proof since riders use it worldwide and all year round. But, you are spot-on, that it’s important to move a tire with a sealant-filled tubeless tire to near the top of the rim. That keeps the sealant away from the valve.
Dried Sealant Issues
One issue you can run into, is having old sealant dry and form a skin over the valve hole. When this happens you can’t let the remaining air out of the tire or put any more air in. This is one of the reasons most tubeless valves have removable cores.
To break the seal, remove the valve core and then use something like a small Allen wrench on your multi-tool to poke inside the valve and break the sealant skin seal inside.
CO2 is Best for Home Brewing!
And for fun, the last word goes to RBR contributor Brandon Bilyeu who cracked me up with his comment, “The only use I have for CO2 is force carbonating home brew beer. For the bike I use a pump… manual pumping to inflate is more calories burned and this means more beer!”
Thanks for all the great comments and tips readers. As I type this, more interesting thoughts are coming in. If you haven’t checked back to the article, here’s the link to scroll down and read the latest: How to Use CO2 Cartridges Correctly When Inflating Bike Tires.
Ride total: 9,562
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Jim Langley is RBR’s Technical Editor. He has been a pro mechanic and cycling writer for more than 40 years. He’s the author of Your Home Bicycle Workshop in the RBR eBookstore. Check out his “cycling aficionado” website at http://www.jimlangley.net, his Q&A blog and updates at Twitter. Jim’s streak of consecutive cycling days has reached more than 8,000. Click to read Jim’s full bio.