ZG, there were two guys that went farther than I did in 72 hours...a little. My riding partner bailed out and got a nap in the middle of it, but he wasn't on schedule to make it to the end of the rally any more, so he just rested up a while and went home instead.
A full tilt run like that requires a lot of concentration, and the willingness and awareness to pull the plug on it if you are not up to it that day. It is the hardest thing to know and do. I had an excellent run, no terrible times with fatigue or anything like that. A whole lot of stuff has to go just right, all at once.
That stretch included half a dozen side trips for bonus collecting, fuel, food, and all that. Heat. Rain. A cold night hauling the mail through Colorado, Wyoming, and into Utah. And a fair amount of doing what the Concours does best. I run a 2 Litre Camelbak, food in the tank bag, and a 3.5 gallons aux. fuel tank. I like to twist it, but at absolutely NO TIME was I going fast enough to get into serious trouble with the law. Just a a matter of staying on the bike and staying alert.