I tried CO2 inflators, and the work well; but found that carrying enough cartridges around to make me feel secure is heavier than just carrying a good minipump. Also, they are wasteful, IMO - you can recycle the cartridges, but that requires a trip to the bike shop or some place like that. So now, I just make do with a minipump.
The only advantage with the CO2 inflators is that they inflate the tire very rapidly. But for me, flats don't happen often enough to require this - elbow grease is good enough.
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Cat 2 Track, Cat 3 Road.
"If you’re new enough [to racing] that you would ask such question, then i would hazard a guess that if you just made up a workout that sounded hard to do, and did it, you’d probably get faster." --
the tiniest sprinter