silly C02 question, no answers at LBS

I can't answer your question, but I am planning on doing the 1/2 esprit montreal triathlon next year. Let me know how it goes...

thanks
Butcher

The CO2 inflator I have instructs to attach the CO2 catridge to the nozzle, then attach to the valve stem on the bike.  I have the Innovations Ultraflate that has a trigger that you pull to release the CO2 once it is attached to the valve stem. 

I've (thankfully) only had to use mine once, but I screwed the canister in first, then attached and inflated the tire.  Once screwed in, the canister may leak very slowly, but certainly not fast enough to make a difference in the few moments before inflating the tire.

assemble the canister/inflator assembly first, then put it on the tire valve. The inflator dealy acts like a little regulator to keep the CO2 cartridge from following newtons 2nd law when you try to attach it.

I don't have any experience with inflators (just got one this season), but the sequence may depend on whether it has a trigger or not. Without a trigger (they may not sell any of these any more), you release the CO2 when you screw the cartridge into the inflator. Most nowdays have a trigger, so either way should work.

And that follows Newton's 1st law which states that the number of flat tires you can expect in an Ironman is one more than the number of CO2 cartridges in your tool kit, multiplied by the square of the distance you are located from your special needs bag.

 

Edited by max 2006-09-11 6:07 PM

Nope, screwing the cartridge into the inflator does not release CO2 on any of the three types I have used, regardless of whether they have a trigger. However, you still don't want to screw in the cartridge until it's time to fix a flat. The reason is because no seal is perfect. Once the cartridge is punctured, the CO2 will leak out overnight if you don't use it.

I have used three types of CO2 inflators. Each one has a different mechanism for releasing the CO2. But in all three, you screw the cartridge into the inflator before pushing it onto the valve stem of your tube.

By the way, the three types are:

1. Trigger - pretty simple and difficult for even the most determined fools to screw up; just squeeze the trigger to release the CO2.

2. Spring - the inflator head has a visible spring that you compress by pushing the cartridge towards the valve. It's a little tricky to use and not entirely obvious.

3. Twist to inflate - this one foiled me in a race because I hadn't read the instructions and could not figure out how to release the CO2. You screw the cartridge into the inflator head all the way. Then you push the assembly onto the valve stem. Then, you UNSCREW the cartridge slightly to release the CO2. It was completely unintuitive to me during the race, so I resorted to using my mini pump (along with unleashing a string of profanity). Anyway, once you know the trick, it's perfectly simple and quite easy to use.

you had a mini-pump and a Co2 on you at the same time! hardcore.

They make a combo pump-inflator (which is what I've got).

AND!

...a patch kit.



Unfortunately what I really needed in that race was a spare tire. It was the Iron Creek Xterra in South Dakota, and I foolishly had some old tires on my bike. Unbeknownst to me, the sidewalls were ticking time bombs due to dry rot.

During a particularly fast and rocky downhill, the sidewall of my front tire split open, and the tube bulged out like an aneurysm. The bulging tumor exploded with a sound like a gunshot, and I looked down to see my inner tube flapping out of my wheel like an angry snake. Unfortunately the snake was quickly tamed when it got entangled in my spokes and then wrapped around the axle of my wheel. The tube was pulled completely out of the tire, except for the part still attached to the valve stem, and wrapped so tightly around the axle that it brought the wheel to a sudden halt.

All this happened in approximately eight tenths of a second.

I'm lucky I didn't go flying over my handlebars when the front wheel stopped so quickly. It took many minutes to unwrap the shredded tube from the axle. I wasted more minutes attempting to use the CO2 inflator to no avail. I then resigned myself to the laborious process of hand pumping the tube. All the while I watched fellow competitors sail past, giving me sad looks of pity as they passed. Note that at this point I wasn't even aware of the underlying problem (the split sidewall).

On the trail again for just five minutes, I looked down and noticed a bulging tumor like a black lemon sticking out of the side of my tire. Now I knew what had caused the violent explosion earlier. I had to fix the sidewall, or my race was over. In a flash, I deflated the tube, ripped a piece out of my number plate, and slipped it inside the tire between the tube and the sidewall. It would have to do. Another painfully long pump session got me back on the trail again, but not before dozens of fellow racers passed me again.

The number plate worked, sort of. The tumor reappeared after ten minutes, but this time it was small, and (I hoped) benign. I decided to ride it out. Thirty minutes later I arrived at T2, a bit disgruntled, but thankful that I was still in the race. I finished fifth in my age group.

Several lessons learned: 1) Very few mechanicals should result in a DNF if you're persistent and use a little resourcefulness, 2) even with a big mechanical, you're not completely out of the competition...you can still have a good race, 3) don't use old tires, and finally, the point of this whole thread, 4) learn how to use your CO2 inflator!