I have been running the preload all the way down to the first click (softest setting). Still very stiff for my weight at 155lbs, that is not including helmet, jacket, boots, gloves, etc. My wife went out with me for the first time on Saturady together we are in the 300 to 325lbs range. I first set the preload at 16 clicks from full soft but thought it was a little to light so we stopped and I went up to 20 clicks (4 more clicks) on preload and that seemed to be pretty good. Yes I would agree the shock spring is to stiff.
Frontier, the manual is right...only in this one case
Turn the adjuster knob all the way counter-clockwise to go to the lowest setting...full soft setting.
Most of us have been finding that only 1 or 2 full turns out from the lowest setting is where we have ours adjusted.
Considering that the adjuster will turn a full 19 turns clockwise...to the full FIRM setting, that shows that we are using about 5% of the adjustment range for our riding.