Road Cycling - What they don't tell you about air pumps

So I get home from my commute, do a quick change, and hop on my bike for a nice spin.

Naturally, it starts to rain, but it feels good and I keep going until I get a flat.

All good, I have a spare with me, and I just picked up one of those nifty CO2 air pumps.
The rain is really coming down now as I merrily remove the old tire, put the new one in and get ready to use my new pump.

Pull the trigger and Wow!, this is cool. Tire inflates and feels pretty good, not a full 100psi, but good enough to finish the 10 miles or so to get home. I reach down to remove the pump and my finger freezes to the stem!

I though I was going to collapse right there from laughing so hard. I had to pick up the tire and pump (with finger attached to stem) and go to a puddle to splash water on my finger to get it to thaw enough to release and keep my skin.

So now I have a freeze burn on my hand in a really cool pattern, and one more lesson to remember.

Just had to share that one.

So now I have a freeze burn on my hand in a really cool pattern, and one more lesson to remember.

Except that some CO2 inflator manufacturers do actually warn you about that. As a matter of fact, the manufacturer of my inflator (SKS) sells their cartridges with a sleeve to help prevent such problems. Although I don't really buy their brand of catridges as replacements (cheaper and just as effective to buy generic), I keep the sleeves from the ones that originally came with the inflator to use on replacement cartridges. Sorry you had to find out about the old PV=nRT (Ideal Gas Law) in such a manner though.

http://www.neebu.net/~khuon/cycling/bikes/Aegis/2001-Aro_Svelte/images/PICT0020.JPG

Oh I knew about it, I think I was humming pink floyd tunes at the time, not my Mr. Wizard theme song ;)
Also, I did'nt freeze to the cartridge, I froze to the stem as I went to remove the nozzle from the stem. Man, I'm still laughing.

One side effect of the freezing of the cartridges is that after pressure has equalized between the air in the tire and the air in the freezing cold cartridge, you can still get more air out of the cartridge after it has warmed back up to room temperature.

Since the cartridge generally only gets a road tire up to about 90 psi on the first inflation, I have been able to get a bit more pressure in the tire by waiting for the cartridge to rewarm, then I use it again to get the tire up to more normal pressure on the second inflation.

PV=nRT at work again.

Stupid CO2 pumps. My frame pump never froze my fingers.

PV=nRT at work again.

See, you can use what you learn in chemistry in everyday life. The next Chem Lab in which I'm a TA I'll have to bring this up. Peace.

Just make sure you express how funny it was :)

I'm still laughing, and not just because my co-workers keep pointing at me and laughing.