We`re hauling only one pound of tea on our aluminum horse built for two, a tandem bicycle we’re riding along the same course as an ancient trade route between the Tibetan Empire and the Chinese dynasties. Our cargo includes another 69 pounds of gear weighing us down as we angle up switchbacks and pound through potholes and washouts. Why would we subject ourselves to this arduous endurance test? To glimpse one of the most treacherous and lengthy trade routes on Earth. At least that is how the route was described by Jeff Fuchs, in his 2008 book, The Ancient Tea Horse Road: Travels with the Last of the Himalayan Muleteers. Fuchs has revived interest in the route after scouting its remaining traces to find clues to the people who last walked it.