Total travel is the first (longest) measure Free sag is the distance that the rear of the bike settles when on the ground, but only under its own weight (no rider). Middle measure Race or rider sag is the third measure (shortest) which should be taken with you on the bike feet on the pegs and all gear on you as well. A good number for the race/rider sag is 4 inches used up when compared to total travel. if the bike doesn't have enough free sag (usually about 1 inch)when you have cranked in the spring to the right rider sag you need a stiffer spring Read here: http://motocross.transworld.net/1000014594/features/tuesday-tip-setting-your-sag/ It really makes a difference to have the correct rider sag. I had a KDX 200 that would not turn well in the woods. Drove me nuts. That's when I learned about rider sag. It was way too soft. I cranked it in till I had 4" of rider sag and voila, it was way better. Before raising the rear susp, the bike was acting like a "chopper" and when I picked the rear up, it put more weight on the front tire and steepened the steering angle. Helped a lot.