Polaris 2003 Universal Snowmobiles - Manual (Page 63)

61
THE PERFECT FIT
M-10 Suspension
Optional Spring Rates - Optional springs have been designed to allow
adaptation of the M-10 to the varied needs of our customers. The 140
lb/in option front arm spring would be used when very light loads are
encountered such as very smooth trails, deep powder or by very light
riders.
The 235/415 lb rear arm spring option would be used by riders in high
load situations such as heavy riders on rough trails or combined total
rider weight of over 350 lbs.
The available springs for M-10 are as listed below.
Location Spring Rate Polaris PN
Front Arm Std
Soft
Firm
160 lb/in
140 lb/in
180 lb/in
7041671-216
7041677-067
7041672-067
Rear Arm Std
Soft
Firm
210/278 lb/in
135/240 lb/in
300 lb/in
7041935-216
7042010-067
7042011-067
Overload 1000 7041936--067
Preload - Is basically the pretensioning of a spring by installing it on a
shock at less than its free length - Free Length -- installed Length =
Inches of PRELOAD OR 10.5″ -- 9.75″ = .75″ of PRELOAD
Dual Rate - Refers to 2 different SPRING RATES designed into one
spring. Notice that M-10 coil springs are often “dual rate” having a
soft (closely wound) area and a firm (loosely wound) area.
Over Load Spring - Located inside the main rear spring, contact is
made with this spring only when the X-OVER tube comes in contact
with it towards the end of the travel, reducing bottoming of the rear
suspension.
X-OVER or CROSS OVER - Describes the transition from one
spring rate to another. during compression travel, the space between
the closely wound coils eventually disappears. At this point, the spring
“CROSSES OVER” from the soft to the firm rate. This term also
includes the transition that occurs when the overload spring is engaged
by the “X-Over Tube” on the rear shock.