C02 cartridges are only for "temporary" air ... WHO KNEW?!!!!

I have had a lot of back tire flats, all in a row lately. I took my bike in to get new tires and asked them to check out my wheels to make sure there's nothing about them causing my flats. I asked the LBS guy tips on using the C02 cartridge, because my dh had mentioned you have to be careful not to ruin your tire valve when you pull them off and I was worried that was why my tires might have gone flat. I then told him my dh had just given me a reminder lesson on how to use the C02 by having me use it on my bike. We let the air out and I filled it with the C02. The next morning, my tire was flat.

The bell went off in LBS guy's head and he explains to me that C02 air is only temporary air. It goes away after around 18 hours. It's to get you home, but you have to refill with your tire pump before your next ride. (He recommends doing it as soon as you get home. Let what's left of the C02 air out and pump regular air in. That way, the next time you go to ride your bike, if your tire is flat, you now it's actually flat and not just the C02 disappearing.)

Anyways, this was news to ME!!! Why hadn't my very experienced cyclist husband told me this?!!! And then I got to thinking that he surely must have, like a year ago when he taught me how to change a tire, and I had just forgotten.

So, he calls me from Utah today, where he had just finished a marathon. After he told me how great he did, I told him I learned something today. And then, as if I'm teaching him something new, I say, "C02 is only temporary air. You have to refill with your tire pump before your next ride." There was silence. And then he said, "Really?"

He didn't know!!! I couldn't believe this!!! This man man came in 4th at Ride the Bear with like 13,000 feet of climbing and thousands of people racing it. He's been a serious cyclist for several years now and has changed lots of flats out on the road using C02 and this man did not know this extremely important piece of information! I told him, if he thought back, it would probably explain some of his, so called, flats and he said I was probably right.

Wow. I actually taught HIM something today. ;)

Good for you! I love it when I teach my husband something. It makes me feel cool. Also, thanks for the heads up, I have been debating on getting a CO2 cartridge or a regular bike pump, I guess now I would need both! Thanks!!!

Hmm, thanks for the interesting info. That kind of makes sense; maybe pure CO2 escapes through the pores in your tubes more easily than the mixture of gases in the air? Although air is mostly nitrogen, if I recall correctly, and that's N2. Wouldn't that molecule be smaller even than CO2 and thus even more prone to seep out? That makes me wonder what the composition (%) of air in our tubes is, and if over time it ends up with different gas ratios than the air around us. Chemistry nerds on TE, help!

Anyway I'm not a CO2 cartridge fan anyway. Every time I try to use one, it blows up or doesn't work or something. I'm going back to a good ol' hand pump as soon as I get my new bike.

I just learned something too! I bet Silver didn't even know this!

I was actually told that Co2 is heavier than air. Thats why is doesn't last. I hate using them as well but its a necessary evil. Flats suck more.

I don't think this is true.

Serious dirt bike racers use compressed CO2.

I think this needs a little research before being accepted as valid. Just ' cause the LBS guy says so, doesn't make it true.

Veronica

My personal research is this is false. I have changed plenty of flats using CO2 and not had another flat on the tire for months. I do air the tire with a floor pump before the next ride so maybe that is why but I haven't had recurring flats on the tire that had CO2 on the road. My husband and the LBS pounded into my head on a skinny road tire air it up before each ride unless you are a fan of leaving the bike open for a pinch flat. I have never had a CO2 filled tire be low in enough to call it flat 18 hours though, 10-20lbs pressure yes but I have seen this on regular old air too.

This is just not true. I usually only inflate every 2-3 rides (unless I've done a particularly long ride). I have on numerous occasions fixed a flat with CO2 and had plenty of pressure in the tire for another ride or two (I like to keep them pretty hard too).

Could it be that you are underinflating? If you are not careful with CO2, you can lose a fair amount of it trying to inflate the tire... if you are underinflated to begin with, you are more likely to flat. Also for some reason tires seem to lose pressure faster when they start from a low pressure (not sure why, but it seems to happen).

I love my CO2 pump :).

CO2 is smaller molecule than N2 - (the main component of air) so the CO2 seeps through the rubber of the tube/tire faster than nitrogen, and so the tire loses pressure faster-- they don't have air in the little cartridges because nitrogen molecules are much less compressible than CO2 so you would need a much bigger cannister if they were filled with regular air..

I'm pretty sure this is true. If I fix a flat with co2 I always have to pump the tire up the next day. I wouldn't say they get totally flat, but pretty squishy. Still I love having cartridges over a hand pump on the road. I still carry a really small pump for emergencies, but there's nothing like changing a flat in 40 degree rain and having to pump and pump and pump with a little hand pump just to get 70 lbs of pressure. Blech - co2 is so much quicker.

Even plain old air leaks out slowly, if I let my tires go a week without pumping them up they'll go from 100 lbs to 80.. its just not as much or as noticeable as the loss with co2.

Well I was skeptical when I first read this, but after I thought about it...

Race cars fill their tires with nitrogen... NOT because it doesn't heat up the same as room air as a lot of people believe... but because it doesn't escape the tires as quickly as room air.

According to a trade organization (fwiw), oxygen escapes through tires 3-4 times as fast as nitrogen. It doesn't give statistics for CO2 (which would have to be somewhat slower than oxygen), but it does say that nitrogen is the largest molecule in room air.

Bottom line is, it's a bigger deal for a car, since you air your bicycle and motorcycle tires before every ride anyhow, but you probably don't check your car tires daily. But yeah, I suppose now that I've read this, if I have a flat early on a long ride, I'd probably borrow someone's air pump within a few hours.

The drastic temperature changes the co2 goes through may affect all this too.

Just a thought,

I have to agree that this is true as well, and BF agrees. Whenever we had flats, we would fill up with CO2 and the next day the tire would be soft and have less air in it. CO2 is perfect to get you home.

Anyways, I always always always pump my tires before a ride. Personally I just feel as if i'm missing something if I don't.

I always pump before my rides so the CO2 issue is pretty much null for me which may be why I say rubbish to it but I still haven't seen a true flat overnight with CO2.

Why pump before every ride? It is kind like how as a kid our parents make us brush every night, it is good for you yes but it also becomes habit. It just makes sense to check with a tire pressure valve every ride so I don't have to deal with pinch flat which pisses me off more than any other flat because it is so easily avoided. I cannot even count the number of times my tire feels okay to the touch but I put the pressure valve on it and it is only 80-90 PSI. Also I get so scatter brained some days I wouldn't remember if I did put more air last ride, two rides, last year. LOL. My 2 cents threadjack. :)

I have noticed that CO2 escapes a lot faster than regular air out of my tubes. It's not constant though and I suspect this may have something to do with the tubes as well (I have a batch of light racing tubes that seem to be leaking faster than my heavier tubes but maybe it's skewed perception).

I always pump up my road tires before rides anyway. If I've inflated it with CO2 the day before and it's particularly low when I start pumping, I empty it almost entirely and start again with "fresh air." :D