Incidentally, I was interested by Sy Reene's CO2 inflation chart. For years I carried only a CO2 inflator with me - no back up pump. After I started riding recumbents I punctured my 20 X 2.0 front tire on our Screamer tandem. I was shocked to discover how soft the tire felt after inflating it with 16 grams of CO2. I'm guessing that the 48 psi on the chart is accurate. That's when I started carrying a pump again. I'm too cheap to use more than 1 CO2 cartridge per puncture.