Originally Posted by
wphamilton
It's getting dark, in a hurry to get home, unscrew the valve nut exactly like always and waste a CO2 cartridge in an instant. Likely I unscrewed the valve core when I though it was the nut turning. With a pump, same thing. After I got that situated, air in the tube, I couldn't get the screw-on pump nozzle off without removing the valve core.
I had this happen once - rode to a gravel road, stopped to let a bit of air out for the rougher terrain... a few kms later I realized I had let too much out.. no problem - "I'll just open the presta valve to pum..."...then the valve core ejected itself over my shoulder into the dust. I did not have a spare tube, just a patch kit, which is quite a bit less useful in that situation. I actually found the valve core after about a half hour of searching and got rolling again.