I refuse to ride without my maintenance gear. That's a simple multi tool, tire levers, pump, patch kit, and 2 tubes. I only started the two tubes thing because of what happened to me a month ago. I was riding along, and I saw a fellow commuter on the side of the road with a flat. He didn't have a spare, nor did he have a patch kit, so I gave him my only spare tube and made sure he was good to go before continuing on my ride home. Not 200 yards down the road, I feel the dreaded slosh, slide and thump-thump in my rear wheel. Karma's a load of sh*t in my opinion, hehe. Even so, I still stop to help a fellow biker out every time. It was a pretty nasty pinch flat that I got from a rough part of the road (I should've checked the air pressure before the ride..). I had to call my wife to come and get me after an hour of unsuccessfully trying to patch it. So I vowed to never again be stuck without a tube, so I carry TWO of them.