I dialed my rear preload down to the lowest setting and that has helped a good bit. I don't ride 2-up and never intend to so I'm not sure how that will affect things, but it would be worth your time to play with the suspension settings. I have the corbin gunfighter seat and you sit a tad lower and about 1" further back. I really like it so far. True test will be a 600 mile ride to Fl space coast next month. Stock seat sucked after 2 hours. FTR, I'm about 5'6" and 160lbs.
Sorry for the delay, I don't get on the forums very often. In your situation, dial it all the way down and use the lowest preload, if you still have issues, you may need to go aftermarket and get some air shocks or a custom fluffy seat or something.The roads here are terrible with lots of breaks and pot holes. There are so many it is impossible to dodge all of them. I have noticed uncomfortable shock to my lower spine when I hit the big bumps. What would be the best preload setting to reduce this shock to my lower back??