For those considering an after market seat, my two cents is to go with Russell. Mine was one of the first Day Longs they did for a Tenere and I love it. I've got 80+K miles on this seat and it still feels great. Russell offers a money back guarantee, but you have to give them 2 chances to correct whatever isn't working for you. And you can get a backrest as well. The backrest slips into a channel built into the pillion seat. I got a backrest with my RDL but have only used it a handful of times so I cannot comment on how well it works. Perhaps a backrest would be helpful if trying to eliminate lower back pain?
The ST deifinitely has a different riding position from any bike I've ridden. I've found that the seat pushes my lower back and gut forward causing a sharp curve in my lower back and the pegs cause enough of a bend in my knees that I can't use them to support my 240lbs. This in turn causes me to support my upper body with my arms and shoulders causing fatigue in them as well as in my head and neck. It's an odd, uncomfortable riding position made worse by my 52 years, 30+ years of which I've spent in the saddle. I've got the tallest bar risers I could find and am going to try lowering the pegs a bit , as well as a possible seat mod. I don't think I can "fix" it all, but I am looking for the combination to minimize it. The info here really helps. Might need to start a thread for Big Guy Ergonomics.
Agreed. I have an Airhawk cushion built into the seats and I have finally succeeded in managing to keep them holding air. On top of that I have just added a sheepskin cover (ordered before I figured out the Airhawk issue) and now I'm awaiting suitable weather to try it all out.