Among the spate of flats I’ve had recently, one stood out as particularly irritating. I was riding down a flat, suburban residential street when I felt the rear tire sag. I pulled over, got the tire off, and got the spare tube and tire levers from the seat bag.
But when I tried to pump the spare a little to mount it on the rim, I discovered that it had a puncture. I always carry a small patch kit with me, so I set about patching the tube. It seemed to have worn with age and use — there was more a crack in the rubber than a puncture. I finished the patch, rested the bike against a nearby fence, and proceeded to clean up and put away my mess. When I walked over to the bike to put everything back in the seat bag, the tire was flat again. I got it pumped it up to 90 psi, and figured since I was only about two miles from home, I could make it back on a soft tire.
I couldn’t. I rode about a half mile, and the tire was flat again. This time, it wouldn’t take air. The puncture must have widened with the riding.
I had two choices. I could pull off the tire and patch the leak I had missed the first time, or I could just walk the bike the remaining distance home. The temperature was about 90ºF (32ºC), the sweat was dripping onto my sunglass lenses, and I was tired and cranky. I walked.
I keep my spare tube in an old sock, to prevent it from rubbing against hard surfaces or sharp-edged tools in my seat bag, so what caused the puncture in the spare is a mystery. I assume it was always there, and I missed it when I put that particular tube in the seat bag.
Has this ever happened to you? What other tips do you have to prevent your spare from getting damaged in the seat bag?
Periodically, it’s worthwhile to check your spare tubes.