Static Sag

With static sag we mean the amount the suspension is compressed with the rider on it and the bike standing still.
The worst thing that can happen to suspension is when it reaches it's limit i.e. locks up. As the road in front of us not only contains bumps as well as holes we need suspension travel either way. Acceleration, braking and centrifugal forces in corners also load the suspension. But because gravity forces us downward you need more suspension travel downward than upward.
Sag is measured by the amount the bike drops down from totally extended suspension.

You'll want about 20-30mm sag at the back and 30-40mm up front (it actually should be calculated as 25% of rear suspension travel and 30% of front travel, but on modern sportsbike the above values should give a good result).

REAR SAG

First we'll start at the back.
Have someone pull the rear up untill the suspension is fully extended (rear wheel off the ground). Then measure the distance from the rear axle to a point on the subframe/seat unit straight above it.
Have the rider sit on the bike without loading up the suspension and keep him balanced while he takes his normal riding position. Then measure between the same two points (rear axle/point on seat unit). Substract this figure from the extended figure which gives you the sag. Adjust the spring collar on the shock, tighten for less sag and release for more sag untill you get the desired 20-30mm.


FRONT SAG

At the front we put a tie-rap arount the inner fork leg and shove it against the dust seal. Balance the bike again with your full weight on it and get off carefully without compressing the suspension any further. Pull the front up by lifting the bars and adjust preload untill you've got about 35-40mm sag by turning the preload adjusters on top of the fork legs. Again tighten for less sag an release for more sag.