This is a 13" rear shock intended for a Vmax (2007) that I intalled on my 2007 SM. This shock comes with 120/170 lb springs.
I consider it a "heavy duty" spring in this application. With minimum preload it works pretty well solo for me. Preload is infinitely adjustable within the limits of the threaded collar. A small HF strap wrench is useful for adjustment.
I also tried the lighter 105/150 springs & they were just too light for this bike.
They are pretty good. I want to run them for awhile and see how they do.
