2005 Ski-Doo Racing Handbook, Page 34Get this manual
SECTION 03CHASSIS PREPARATION
Coil Springs
The free length of coil spring is the length with no load applied to the springThe spring rate of coil spring is defined as the amount of force required to compress the spring one inchIf 100 pound force compresses spring inch it is referred to as having rate of 100 lbfin (pounds per inch)If 150 pounds of force is required to compress spring inch then it would have rate of 150 lbfin (see following illustration)A01F1IA
FREE LENGTH
SPRING RATE100 lbfin
SPRING RATE150 lbfin