This morning before leaving I refilled my tires. It was about 60 degrees F. I filled them to near max. Everything was fine when I got to work. When I went out to get lunch, the back was flat. No just flat, the tire was partially off and the tube had a slit it in about 8 inches long. It was probably about 75 F by that time. I figure the air must have heated and expanded during the morning. I can't think of any other explanation. So, a word of warning during this time of year of cool nights and warm days. (In both hemispheres, I would think, eh?) So, always carry a spare tube and the means to inflate it -- a hand pump or CO2 cartridges. I was glad I did!
It was the tube that came with the used bike, so perhaps it was old and weak anyway, and this just pushed it over the edge. Maybe in the future I should consider just replacing both tubes right away whenever I buy a used bike.
Anyway, here's the tip. I was on my way to get lunch at the mall food court near my office. I've said this before, and some were skeptical, but I really think that a mall perimeter road (the one that goes around the inside of the parking lot, next to all the entrances) is a great place to practice riding in traffic. The posted speed limit is 10 MPH, and most cars actually do go slowly because the straightaways are all pretty short, they generally aren't going far on it, and they do realize there are blind corners and a car could come out of a parking row at any time. But on a bike, these are great practicing speeds (and I probably slightly break the 10 MPH limit most of the time). You can take the lane the entire time for visibility (both yours and theirs), and most of the time you are keeping up with the cars and not impeding them at all. As always, scan for cars pulling out, and pedestrians to slow down or even stop for if necessary. Obey all the right of way rules, and stop and take your turn at stop signs. With everyone operating at slower speeds, and in a closer space, I've found negotiation and eye contact to be much easier than on the open road. Hence, great practice for it. Sometimes I even ride the complete perimeter once or twice, about a mile each circuit, just for fun. (At least relative to the heavy and faster traffic surrounding the mall and my office, which I would have to go through to get to any better recreational routes! )
Your experience may vary. People are generally friendly in Maine, even in a mall parking lot (except maybe in late December), so I can't speak for all malls.