I've had one slightly long ride on my c14, about 2 hrs and the only thing I noticed was my legs were starting to go to sleep because the ride was so comfortable I wasn't moving them. The return trip of 2 hrs the next day, I made sure I wiggled them a lot and was fine. It rides so smooth its awesome, especially after a trip from Utah to California on my Honda Shadow Spirit 750 wow talk about my butt hurt!
