Place the bike on a stand with your wheels un-weighted. Take a measurement from the rear axle to a fixed point vertically above (eg. muffler bolt/rivet). Making a small mark with a pen on the guard for a reference point is a good idea.
Take the bike off the stand, place the rider with gear on the bike with a normal riding position with their feet barely touching the ground or on the pegs with someone helping to aid balance. Take another measurement from the same two points as before.
Too much rider sag indicates you must increase pre-load to the spring by firstly loosening the spring adjuster found at the top of the spring. Then adjust by turning the lower adjuster ring clockwise. Too little rider sag indicates you must decrease pre-load by turning the spring pre-load adjuster counter clockwise. Next you should check your bike’s free sag.
Take the bike off the stand and bounce on the bike to allow the suspension to settle. With the rider off the bike take a measurement between the same two points again.
Subtract measurement 3 from measurement 1. Your bike should sag approximately 25 – 35mm by itself off the stand after your have set rider sag.
Hint: Less than 25mm indicates a stiffer spring is needed and more than 35mm indicates a softer spring is needed.