I weight about 170# and adding enough pressure to reduce bottoming made my SG ride like a truck, and I never found a sweet spot with those shocks. I punted and bought some Progressive 440's, which is big improvement.

Some have changed the fluid to something a bit stiffer, like a 7.5- or 10-weight shock (not fork) oil, but this is not an easy procedure. Bel-Ray racing shock oil is often suggested. There are some threads on doing this which requires building a simple jig to pump the old oil out. Inverting alone doesn't work, as after a week upside down one of mine has dripped out maybe 1 oz. (out of 10 oz. total).

 

I run 14 lbs for 2 up and i have never bottemed out yet-ride safe