Well, I was going to ride to work today after a couple of weeks of not riding. I got on the bicycle (my old Schwinn LeTour), and was about a mile away when the noise I had heard from the bottom bracket translated into a wobble on my left crank arm. I recognized it, and turned around. The crank arm came completely loose (off the bike) just a few hundred yard from home. Well, I showed and drove to work. This evening I switched out the damaged crank arm, and will try again tomorrow morning.

John