I'm with Bucky. Just finished the GA. rally a couple of weeks ago for the second time. Over 2100 miles including the rides. On the first leg I went 592 miles, 11-12 hours on the bike after some detours. Don't get me wrong my butt was pretty sore after that but if you set these bikes up right, you can tour. I would recommend a touring seat like the Triumph Gel seat and possibly some risers and floor boards or Kuryaken pegs with stirups. The America and Speedmaster are a couple of the most versatile bikes out there. I am also a big guy 6'2" lets just say over 250lbs.
