I carry CO2 and a CarbOne mini pump (about 55 grams). The CO2 makes getting back on the ride really quick. The pump is for when there's no other choice. Keep in mind that if your use CO2 you'll need to replace the air when you get home. Tires with CO2 alway seem to lose pressure by the next day.
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A conclusion is the place where you got tired of thinking. - S. Wright
Favorite rides in the stable: Indy Fab CJ Ti - Colnago MXL - S-Works Roubaix - Habanero Team Issue - Jamis Eclipse carbon/831