There’s nothing like the convenience of CO2 for a quick way to pump up your tire after repairing a flat. But, there’s also nothing like the reliability of a good old fashioned hand pump.
I carry both to get the best of both world’s, as Hanna Montanna would say. I’ve twice had CO2 cartridges fail on me. And, if you’re out riding alone, finding a ride to the nearest bike shop can be a challenge. And phoning home for a ride can be a very time consuming recovery method. Better to be prepared.
I picked up the Topeak Master Blaster (affiliate link) last season and it’s worked out great. It’s a small, lightweight carbon fiber pump that mounts right next to the water bottle cage. I wouldn’t want to pump my tires with it all the time, but it’ll definitely do the job in a pinch. It’s a small price to pay in terms of weight in order to avoid getting stuck by the side of the road for something silly like a simple flat tire.