I carried C02 on my mountain bike for a few years.. finally had the chance to use it coming down Porcupine rim once. Somewhere between the cartridge, its dispenser nozzle, my presta valve adapter, and the new tube, I didn't have a good seal and pfffft.. borrowed someone's pump. Probably won't go down that road again.
I'm still struggling with where to mount all this stuff.
82 fj40, 99 uzj100, 06 gx470
97 DR650, 05 525EXC, 01 XT225, 89 TW200, 09 TTR125, 07 TTR90, 07 CRF50