The original flat was a small tear on the inside of the tube, and some of the spokes seemed a little loose, so I pulled out the truing stand and tried to get everything to an even tension, true and round. I got it done, and then thought about how long it's been that I've had that wheel and have never greased the bearings, so I did that as well. It's an AlexRims R500 with a Shimano H-2200 hub, everything looked good with no sign of contamination.

Now if I could only figure out what I'm doing wrong patching tubes...... I've never had enough flats to practice much, but I think I need to get it figured out. I almost never have them last very long on road tires.