My essential cargo includes a multi-tool with tire levers, 1 spare tube, and a Topeak dual action mini pump on the down tube. however, I've been considering ditching the pump for CO2 and a patch kit. The pump is just heavy and ungainly and ***** to pump a full tire, and a small patch kit and a couple of CO2 cartriges would fit nicely into the seat bag. I figure the odds of getting more than 2 flats on a ride is pretty slim, so 2-3 cartriges would be plenty. Plus, some mulittools now incorporate an inflator, which is even more convenient.

Any input on what you carry and your thoughts???