To prove my point, I am willing to admit to doing something really dumb. A few weeks ago, 18 miles in to my 30 mile ride, I had my first flat. Everything went just dandy as far as replacing the tube. I opened up my C02 pump to invert the cartridge and resealed it. I was expecting to hear the cartridge engage ( a small hiss, pop or something). When I didn't hear anything, I unscrewed the handle and, yes, the handle and cartridge flew across the road and into the nearby woods. The cartridge had seated properly. I just did not realize it. Anyway, a call to the wife and a couple of miles walk, I was back home to wipe the egg off of my face. I went right out and bought a mini pump. If you do decide to go with CO2, don't expect to hear a noise when the cartridge engages.