2003 Polaris Deep Snow Snowmobiles Service Manual, Page 242Get this manual
SUSPENSIONS Springs
Two types of springs are employed in Polaris suspensions, coil springs and torsion springsFollowing is some of the terminology used when referring to coil springsS Free lengththe length of coil spring with no load applied to the spring Installed lengththe length of the shock absorber between the spring retainersIf the installed length of the spring is less than the free length, it will be pre-loadedSpring ratethe amount of force required to compress coil spring one inchFor example, if 150 pounds of force are required to compress spring inch, the spring rate would be 150 #inStraight rate springthe spring requires the same amount of force to compress the last one inch of travel as the first one inch of travelFor example, if 150 #inspring requires 150 pounds of force to compress it one inch, 300 pounds of force would compress it two inches, 450 pounds of force would compress it three inches, etcProgressively wound springthe rate of the spring increases as it is compressedFor example, 100200 #inrate spring requires 100 pounds of force to compress the first one inch, but requires 200 additional pounds to compress the last one inchCoil Spring Length