Before I made the switch to the 440s, I personally found that the bike bottomed out hard with low air pressure in the shocks. I found that with the wife on back I had the best ride at 40 - 45lbs, and no shes not a big gal. I'm 190# and she's 130#.
I initially thought that the ride was harsh and so I let some pressure off, down to about 12#, then it REALLY rode harsh, it was hitting the stops HARD. So I gradually began to increase the pressure until I was able to stop the bottoming. It was still a stiff ride but not bone jarring like hitting the stops. Be careful though, you can't put more than 50# in those shocks. I know this sounds backwards but it worked for me, (at least until I switched to the progressive 440 standard duty 12.5 inch rear shocks and put SE heavy duty oil in the front forks. [smiley=drink.gif]