I had a sudden loss of air pressure from the rear tire (split valve stem) while traveling on the highway at about 80 MPH. The first thing I felt was a slight wobble which quickly developed into a faster wobble with a sense that I was about to be thrown to the ground either left or right. I was able to loosely hold the bars while I coasted to the shoulder and slowed, without using the brakes, as I didn't know yet which tire was the culprit. I was able to bring the bike to a safe stop on the shoulder. The main point of this post is to explain this all happened in a matter of seconds and not tightly fighting or holding the bars and not using the back brakes, when the wobble began, I think kept me from going down. Suffice it to say I was really fricking busy for a few moments! Just a PSA for my fellow riders.