For years I used a small bell tire pump that strapped to my frame or I would stick inside my back pack. On my last ride it broke and this time was considering using co2 cartridges instead of a mini air pump to carry with me when I ride in case of a flat. I've never used co2 to inflate my tires. Does anyone use it? Does one cartridge fill one or multiple tires? How many psi can I expect from using a co2 cartridge?