Joined: Jul 2002
Posts: 40,863
Likes: 3,115
From: Sacramento, California, USA
Bikes: Specialized Tarmac, Canyon Exceed, Specialized Transition, Ellsworth Roots, Ridley Excalibur
On a training ride or commute: both. CO2 for the first one gets me back on the road quickly and gives me a chance to catch the group or make it to the office on time. If there's a second, I'm going to miss the group or be late, so I might as well take my time. You didn't ask but I carry a tube and a patch kit for the same reason.