CO2 Cartridge Question

[keno]

I seem to be in the midst of a fall flat-tire festival. I am in the CO2 cartridge camp, and have run through the 16g cartridges I have been using. My trip to the LBS put me eyeball to eyeball with the jar of 16g cartridges they are selling for about $3 per. I blinked and retreated to the Wal-Mart a mile down the road and saw a 15-cartridge carton of 12g cartridges for $7.98. I took along a 16g cartridge to compare dimensions (I use an Ultraflate and never had a problem with it) and the 12g and 16g are identical. So I made the big investment in 12s.

Came home and did a little bench test. I completely deflated the Veloflex Pave (22mm) sitting on a Mavic SSC SL rim and inflated it with the 12g cartridge. It brought the pressure to 90 psi.

Questions:

1. The SSC SL rim is deeper than the Open Pros I also run. How much more tire pressure will the same tire on an Open Pro rim inflate to with a 12g cartridge?

2. Is 90 psi enough pressure to allow me to complete, not shorten, my ride without a snakebite flat?

3. Since the Ultraflate allows me to use a cartridge parially, I can top off the tire, bring it to say 110 psi, and still have what is left in the cartridge plus another one to fill on the subsequent flat. Would you top off?

Worst case, the 12g cartridges end up costing a little more than a buck a flat if I use two of them, versus three bucks for the 16g, and best case, about 50 cents if 90 psi is sufficient.

keno

[Kevan]

but here are some thoughts:

Yes, you can finish a ride on 90 psi. In fact the typical recreational rider doing a mile century will probably have about that much pressure left in their tires upon returning back to the start. The low pressure does mean you should be more careful with your riding cracks and potholes.

I never found the "topping-off" feature of co2 to be that successful. Also, once a bottle has been used even partially the unused portion usually leaks its way free if you don't use it in the near future. Fill the tube and properly toss the bottle.

I've had a good streak of luck this season and still have the 2-16's taped together and secured in my saddlebag that I started with. I don't think my wee-bag could store a third bottle. :D

[JohnS]

1. It doesn't make any difference. The CO2 goes into the tube, not the rim.
2. Maybe...how much do you weigh?...what kind of roads?
3. It's up to you. The cartridge will slowly leak.

[keno]

When writing my note, I thought a bit about your first point, but concluded that with a deeper rim the tube will fill whatever space is available, including the extra volume in the rim. I concluded that, as a result, the resulting pressure would be lower in a deep rim application with the same cartridge content. If you see it otherwise, please explain it to me.

I weigh about 185 lbs. I would call the roads good, pretty smooth but with patches and some unavoidable rough areas. I live in the country.

I'm satisfied that I would dispose of the partial cartridge after the ride if I topped off because of leakage. I would top off only if necessary to bring the tire pressure up to a level needed to avoid a snakebite flat or create decent ride quality.

keno

[Sandy]

You might call Innovations in Cycling at 1-800-340-1050 and ask people who produce the little critters (8-5 Mountain time).

You might also want to go to the old forum and do a search, as there were several excellent threads on CO2 cartridges (none on CO1, for some reason).

The 12 gram CO2 cartridge inflates a 700 tire to 90-100 psi. The 16 gram to 125-135 psi. I use only the 12 gram ones (non-threaded), and always top off, by using part of a second cartridge. I have never gotten a pinch flat using this method. The second will increase the pressure a desired amount. Try taking a air pressure gauge with you to test the differences.

As I am sure you must know, since your IQ (and Fly's IQ) is at least 100 points more than mine, let all the gas out of your tire when you get home and refill with air (and whatever is up there in New Jersey, where you live) since if you do not, your tire will be at a low psi the next day.

Ride with me, since I keep buying both tubes and cartridges, not because I am having flats, but I keep giving my tubes and CO2 cartridges away, when helping others who are having flats.

Don't believe ANYTHING that Kevan says, as I have recently found out that he is an industry spy from Calfee. He wants to find out Serotta's design secrets. :)

I hope that you come down for Bullet Bob's and Road Rocket's ride.

I am not smart enough to be able to figure out answers to your questions concerning different rims and the fact that you use 22 mm tires versus the more normal 23.

I do recall on the old forum someone say to be careful about using certain Wal-Mart cartridges, since they are used in hunting (or something like that)and have some oil in them, for some reason (gun, I think).

I owe you a phone call. Thank you for your last email. It was well received.

Sandy

[keno]

Thanks for the response. Oil? Wow, and I thought that I was buying CO2. I'll go read the label promptly. BTW, Too Tall and fly are heavily invested in Wal-Mart CO2 cartridges, which is why I never gave it a second, let alone first, thought.

Is Road Rocket the lovely Beth, soon to be SpectrumBeth?

It is written that I plan to ride on Saturday with the usual pumpkin head suspects. Bad weather and my questionable karma are all that might intercede. See you then. I think I remember who you are and what you look like, but I'm sure that if I don't, someone will introduce us. Once we get on the road I'm sure I will recognize your inimitable riding style in all events.

keno

ps Sandy, just read the label. Did not see any reference to oil but there are small amounts of rat feces and trace amounts of halvah in there. I guess CO2 stands for Contaminated, Too.

[JohnS]

The place where the rimtape is, is the same on about all rims. The tube doesn't conform to the inside of the whole rim. Tire volume (width) would be more of a consideration.

[BumbleBeeDave]

A 12 gram cartridge fully emptied will fill a 26" mtb tire.

A 16 gram cartridge fully emptied will fill a 700c x 23 road tire to approximately 110lbs.

BBDave

[Kevan]

A breath from Sandy fully emptied will fill the tires on an entire TdF peleton. :D

[dirtdigger88]

I carry the 12g units. I figure that gets me 95 psi- I normally only run 100-110 psi so that lets me finish my ride with no worries.

Jason

[keno]

the whole story is at

http://www.innovationsaz.com/iaz-typical_yield_co2.htm

[Ken Robb]

on my 26x2" 1 12gr leaves the tire very soft and 2 12gr fel just like the 60psi I inflate to for riding on pavement.
1 12gr into 700x23 to 700x28 feels like the110 to 100psi I normally run. I don't top off with a second cartridge and ride normally.
RE: the oil in cartridge question. It is probably true sometimes as the instructions for Daisy CO2 guns suggest using only their brand of cartridges because they contain lubricants that will save the barrel of the gun. Since many oils will cause rubber to deteriorate I don't use Daisy brand in my bike tubes though I do use off-brands sometimes in my Daisy.

[Sandy]

My 12,000,000,000,000,000,000,000,000,000,000,000,000 ,000,000,000,000 gram cartridge will work just fine for Kevan. Once the tire is heated up a little, bang goes the tire with the force to send Kevan and his Calfee a very long ways from this planet. The cartridge is quite heavy in my saddle bag, but, oh boy, it will be fun to see that Kevan go for the ride of his life- Perhaps the last ride of his life..... :D :D

C02 Cartridge Carrier,

Sandman

[vaxn8r]

Keno, I've been using CO2 for about 7 years. Last week I flatted, refilled with 12g, about 90 psi +/-, about 2 miles from home I ran over a rock and got snakebit. Dang it! I actually yelled something else just like that.

Anyway, that's the frist time that's happened to me. I've never aborted a ride due to a first flat and I only carry two tubes and two cartridges. So far so good in the last 30K miles. I don't plan on doing anything differently in the future. 90 psi will, 99% of the time, get it done.

[Ozz]

I use the 16g cartridges cuz they do get my 23's up to about 115 psi or so...not that I have ever measured the pressure.

I flat so infrequently, that spending an extra $1 for a cartridge is insignificant. The annual cost of my CO2 is "less than a latte a month"...much less actually since I have only used two cartridges this past year.

My thought on flats and CO2 is that the "repair on the road" just needs to be good enough to get you home or to the next bike shop where you can use a real pump and pressure gauge.

BTW - what ever happened to your Velomax wheels? Did they ever repair / return / replace them??