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I need to inflate near flat tires for four bikes. This looks already laborious, so I started to think about CO2 cartridges I have seen in the bike shop. While looks somewhat expensive, would be OK if more than one tire could be inflated with the same cartridge.

Can a single cartridge be used to inflate more than one tire, assuming that all bikes are standing nearby? How many regular (road, not racing) tires could it inflate from close to flat condition?

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    Judging from @Criggie's answer, you would need to buy 20g or larger CO2 cartridges in bulk. That would add up to a fair bit of change over the years, plus a lot of metal waste you'd be producing. You also don't get to control inflation pressure as closely as with a regular pump. It's going to be harder to just top off the tires. You can do this if you want, since you presumably live in a free country. However, is a floor pump that laborious? I have to ask if you've ever used a decent one. – Weiwen Ng Sep 10 at 10:40
  • Don't inflate your tires with CO2 except in case of emergency: tires filled with CO2 deflate much faster than tires filled with air because CO2 seeps out of the quite easily. Don't expect to keep CO2-filled tires hard for more than a few days (or even less). – Roel Schroeven Sep 10 at 22:44
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CO2 cartridges are fine if you use them in the intended way: Roadside emergency. Otherwise they are a terrible waste of energy, resources and money. Normally a single cartridge is just enough for one tyre. You will also lack means to control the pressure that you put into the tyre. Which is OK in an emergency where you just need to have it inflated and eventually be able to move on and get home

In this case, you better invest into a decent track pump with a pressure gauge that you will get for a dozen or so cartridges plus applicator.

Note: a cartridge is for one-time use only. If you inflate the tyre and store the cartridge in your saddlebag because there is still some CO2 left, which is difficult to estimate anyway, the cartridge will empty completely within the next few hours. The system isn't that well sealed against leaks of the remaining gas.

  • Note that if you really want to use CO2 and/or avoid the need for any manual exertion or power equipment at the point of filling, $5/kg (typical price for dry ice) is a lot cheaper than buying 0.012 kg cartridges. :-) You can easily build an apparatus for filling out of an empty soda bottle - they can handle at least 100 psi. – R.. Sep 10 at 15:37
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    @Benjamin: No. OP's question is about inflating tires in bulk, for which canisters are a ridiculous solution. They're a very reasonable solution for on-the-road. – R.. Sep 10 at 16:39
  • @R.. Ahh, I see that now. If the OP wants to inflate tires in bulk, a portable air compressor is definitely the way to go. – SurpriseDog Sep 10 at 16:45
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A single 12 gram cartridge is just about capable of filling two road bike tyres to good-enough pressure to ride.

The same cartridge will barely fill a single 2" MTB tyre to a useful pressure, which is why MTB riders may carry 16g, 20g, 25g, 40g, or even 50g cartridges.

For completeness - here's a chart I found showing how many tyres an air cartridge will do. It doesn't allow for the much higher purchase cost of the larger cartridges though.

https://i.stack.imgur.com/eNvZZ.jpg


Other Solutions

Preference 1 is to get a full sized track pump for at home enter image description here

optionally buy a portable track pump for on your bike. enter image description here

You can also use a plug-in car tyre compressor for MTB bikes but they often can't get to ~100 PSI for a road bike. Plus they may need a 12V source, which is a car battery by design.

enter image description here

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    That chart seems a bit old in that many current road bikes, including performance road bikes, are actually on 28mm tires. Some can take bigger ones, too! I got 35mm tires for my gravel bike only to find that 700c gravel bikes are taking more like 40mm tires in that wheel size, and bigger rubber in 650b. So, I'm honestly not sure that a 12g cartridge could do 2 tires on some current road bikes. Even with 23mm tires, if you had to split the gas between two bikes, you'd be at risk of pinch flats. – Weiwen Ng Sep 10 at 10:35
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    @WeiwenNg yeah its a good decade old that chart. But 23c then is 23c now. So interpolate for your current tyre size. I'm tempted to do a complete chart for every tyre size/width based off a volume-of-a-torus formula... would that be better? – Criggie Sep 10 at 11:36
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    It would be better, but I'm not sure it's worth it. The OP's proposed use case is a bit odd and is going to have them run through industrial quantities of CO2 cartridges. My comment was more intended for the OP's awareness in any case. I didn't phrase it such that it was clearly directed at them. – Weiwen Ng Sep 10 at 15:31
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    12 V Compressors are great for bikes if you have them near your car. I like that they are less noisy than a full size compressor and much slower, so you can have fine pressure control. It is true that many don't get up to 100psi, but it is not hard to find one that does. There are cheap adapters to fit presta/dunlop valves. There are also battery jumpstarter-compressor combos that would fit just well if you don't have a car near the bikes. Given the small volume of a bike tire, a single charge should be more than enough for a dozen tire top-ups from zero. – Jahaziel Sep 10 at 22:22

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