I have a '07 WR450F that I just swapped out the front forks from a '06 YZ 450F. I am looking for suggestions on how to calculate the front fork spring rate being that the WR is about 20-25 lbs heavier to start with. Add in the oversized (3.2gal tank), dual sport kit, the real heavy CA lic plate :-). I am 205 without gear and the gear adds another 35lbs. I would think the bike weight difference, being dispersed through-out the bike, would cause a different spring rate calc than if it was just my lard ass adding 20lbs being centered over the bike. Or am I over thinking this?