Took the Fatty took Colorado and loved the mountains except... The reduced horsepower. I actually expected this. Going from the Kansas into the mountains of Colorado... no surprise there. But what did surprise me was the loss of brake pressure. Coming out of Rocky Mountain National Park, my rear brake quit on me... not entirely but they definitely weren't grabbing. This freaked me out so I stopped and checked the lines. Every looked good. Checked the reservoir, plenty of fluid. I went to the nearest Harley shop and the guy told me "You must be part of a Missouri or Kansas convention cuz you're the sixth person to come in with that "problem" today. He said it's perfectly normal due to the change in altitude. He advised me to use the front brake, flutter the rear a lot and down shift then flush the brakes when I got home. I had never heard of this. Still seems strange to me.