Phantoj

Worst case scenarios:

1) You muff the inflation process somehow (unfamiliarity with the valve head, for example) and waste your cartridge without getting the tire inflated (this happened to me).

2) You have managed to pinch your tube putting the tire on, and you waste a cartridge filling up a tire with a hole in it.

3) You get more than one flat. (Or more than n flats, where n is the number of CO2 cartridges you have.)

This is the fear with CO2 - a finite number of inflates. Of course, you carry a finite number of tubes, a finite number of patches, etc...

Panthers007

Never heard the "CO2 more soluble" routine before. That's interesting. Off to do some research....(BOOM!)

Al1943

I may have said that backwards. It may be that the rubber is more soluble to CO2 than to air. Anyway, it has something to do with solubility. You should be able to find several threads on various forums addressing this issue.

johnknappcc

I would have to disagree, most pumps wont give an accurate reading at first because the valve isn't fully open (unless you prime them a little by letting out some air). But after the first two pumps or so the gauge should be accurate (within about 10psi). It's just a little hard to read, but from what I've found pretty effective. However, there is no substitute for how a tire feels at pressure, that's a good backup gauge.

Panthers007

Okay - an update if you will:

18 hours ago I deflated a Specialized tube in my Conti Grand Prix 4000 S tire - which are 700 X 23C. I then blew it up with an Ultraflate CO2 pump. The inflation was 98psi on my Planet Bike gauge.

<drum-roll please>

The current reading is 68psi. That is a notable drop from the tires I inflate with my regular pump. Now if I only knew why.....

Retro Grouch 

That's more of a drop than I would have expected but I've never bothered to measure it. Do you by chance use ultra light inner tubes?

Panthers007

Nope. They are regular tubes. I don't buy into the ultra-light of weight-weenie items for my tubes - or tires either. I took this into consideration when I did this test so as to remove other possible causes or contributory factors.

But now you've peaked my curiosity. Maybe I'll go hunt up a ultra-light tube somewheres...

gjarreau

I got a flat yesterday and used a cartridge. I bought them bulk from amazon and they are threaded. I the tire inflated fully with one cartridge and I rode in to work. I rode back home and as I turned into my driveway, BAM...flat tire. When I got to work this morning my coworker (who also rides) said that you are supposed to change the tube as soon as you can and use a regular pump to inflate. He said the people at his bike shop told him that. He also said something about the CO2 corroding the rubber, but since this is 2rd hand info, it may not be EXACTLY right. However; I can say that while I have never heard this before I seem to recall that when I have used them in the past, the next flat was coming the next day or very soon. I don't know how many other people have experienced this but I checked the tube yesterday and it split right on the seam. Very suspicious.

HillRider

Well you resurrected a thread that's almost 6 years old but your questions are valid.

First, CO2 does nothing to harm or "corrode" the tube. That's nonsense. What CO2 does do is "leak" out of the tube faster than air since it is more soluble in the rubber and diffuses through more rapidly. You do well to let the CO2 out of the tube and re-inflate it with air as soon as it's convenient otherwise the pressure will go down faster than you are used to. That's not an emergency measure at all but worth doing.

Unless you used a huge CO2 cartridge, which should have caused an immediate failure, your explosive flat followed by finding the tube split is almost certainly the result of not having the tire and tube seated correctly when you first fixed the flat. You most likely had part of the tube trapped between the tire bead and the rim and that's where it was pushed off and failed. You were lucky it waited as long as it did!

digibud

My 2 cents on C02 is that it is fantastic for getting home when you have a slow flat and don't want to take the time to fix the flat. I got a slow flat in the rain when I was late for a date and with C02 I was able to fill...ride...fill...ride...fill...about 4 times. Filling took less than a minute each time and it was great. Same happened just the other day when my wife flatted near home. I've found that 20 pumps with my Lezyne road pump + one 16 gram cartridge fills my 25C tires perfectly. I always carry my pump. A bad day with a group ride or a long day can see me using two or three C02 cartridges, although that's rare. Having a pump is, IMHO, more important than having C02 but C02 is definitely nice. Do know how much C02 your tire can take. I watched a fellow on a race blow his tire up by filling it too much with C02. Sounded like a *** being shot off.

HillRider

I also carry a mini-pump along with a couple of CO2 cartridges. The mini-pump will easily fill the tube to 20-30 psi and assure it holds air and is seated properly, then a 12 gm cartridge gives me about 100 psi in a 700-23 tire. The CO2 is convenient but the pump is essential.

Jed19

Yep. My strategy too. And then make sure I totally deflate the tire to get rid of the lighter CO2 molecules, then reinflate with my floor pump before my next ride.

HillRider

CO2 isn't lighter than air, it's molecular weight is 44 while air averages about 29. However, despite it's greater molecular weight and size, CO2 is somewhat soluble in common rubbers so it dissolves in and diffuses through the tube wall faster than air. And, yes, I also deflate the tube rather completely after using a CO2 and refill it with air.

rydabent

I alway use CO2 since almost every mini pump I have carried failed. I now carry a higher priced one, but then the first one didnt work at all.

Wilfred Laurier

I've never heard of someone getting their *** shot off! Sounds awful!!!

HillRider

Yeah, most mini-pumps have a rather poor reliability reputation. I finally bought a couple of Lezyne "Road Drive" pumps and, so far so good. They are well sealed and the separate air hose means you can really bear down on them without risking snapping off the valve stem.