We purchased a 2004 GL1800 with CSC kit. It has the independent rear suspension. The trike rides considerably rougher than the 2 wheel GL1800 we replaced it with. As far as dips and bumps it rides as smooth as the 2 wheel version. But, when crossing train tracks or entrance drive gutter drains at an angle, or when only one rear wheel finds a dip or rut, it tends to rock to one side and this aggravates the disc in my wife's back. Says she feels as if she's getting whiplash. Is this just a characteristic of 3 wheels in general, or is there an adjustment to help soften the ride of the rear wheels in general? I run about 25lbs in the rear tires because 32lbs was a little too harsh. I noticed that the rear spring has a threaded section on each end for adjustment of spring rate and there is a lot of threads exposed towards the ends. Looks like spring rate is set pretty high for each wheel. Any suggestions?