I have a frame pump on my Fargo as one source of air for when my tire goes pllllllll. I've found that I am less likely to damage the presta valve with a CO2 cartridge than with a mini pump. If you are tired, hot, sweaty and you have to fumble around with the air pump to get a good seal, you risk bending, or worse, breaking off the valve. On the other hand, you may have a cartridge that is a dud or the mechanism that screws into the cartridge is faulty so it's always good to have a backup for that very reason.