I've been trying to figure out how to adjust my SPV fork and rear shock. I have heard a few different recommendations from heresay, MTB Action magazine, and a Manitou tech. I can't tell a big difference other than the stiffness. None of my forks seem to bob with normal spinning, but all of them bob when I stand up. Anyway, I honestly don't know what is going on inside the SPV shocks and forks. It seems to me like both the red and black valves are adjusting stiffness. Specialized had a movie on their site showing how the Epic worked, but I have yet to see anything like this for SPV.