@noglider Tom, that sounds crazy to me. As a fellow teacher, I want to make sure that I can fix a flat on my commute so I'm not late. A small repair kit and pump doesn't weigh that much or take much room (I only include a spare tube, allen wrenches, spoke wrench, tire irons, tubular sealant, and a small tubular patch kit). In the past 8 years since I started teaching, I've only flatted on my way to/from work about a half-dozen times, but I'm always prepared. I typically ride Paselas on my commuter, but also have a couple bikes with tubulars I also use for commuting. I get the desire to have performance tires, even on commuter. I can typically change a tire within 3-5 minutes, slightly less with a tubular. My commute is only 4 (uphill) miles, but changing a flat is almost always going to be quicker than walking.