The weather was nice, albeit quite cold. I got dressed up and left around 10:30. After a good 10.5 miles I could tell my rear tire was losing pressure. I stopped and sure enough, it was very low. To my dismay I found that I had only another leaky tube in my saddlebag. Not even a tire lever. So much for that.
For some odd reason there weren't many people on the road. So I sat there a while and finally a woman came by and stopped. All she had was a cartridge. I did not want to waste the cartridge on a leaky tube so I told her I would flag down another person. More waiting. Finally, a guy came by and he too, only had a cartridge. Left with no options, I decided to inflate the tire and see if I could make it down the hill to the bike store (about 3 miles). It worked.
After buying a tube, levers and an inflation cartridge, I replaced the tube and rode most of the rest of my planned ride -I had to cut it short to be back in time for an appointment- without much problem. Approximately 35 miles, on the Specialized SL. It is a nice bike, too bad the tube was leaky.