I like to see about an inch and a half on the middle setting. I don't MX so maybe my measurement is erroneous but that's my personal preference. I had my 400EX shock and on the hardest setting it sagged about an inch and a half. For most, that would have been WAY too hard but not for me. Considering I'm mulling over a slight extension to the swingarm, I put the LTZ400 rear shock on (stiffer) so now I'm about at the same amount of sag with the preload at only about 1/4 of the way down (lots of spring to grow into later!)