8.11
Steering and Suspension Systems
8
9923396 - 2007-2012 EDGE/Widetrak LX Service Manual
©2011 Polaris Sales Inc.
During acceleration, the rear of the suspension will
compress and the IFS will extend, pivoting the machine
about the front torque arm. Because of this pivoting effect,
rear spring and spring preload also have some effect on
weight transfer. Softer rear springs, or less preload, allow
more weight transfer to the track and reduce ski pressure.
Stiffer rear springs, or increased preload, allow less weight
transfer to the track and increase ski pressure. The main
function of the rear torque arm is to support the weight of
the vehicle and rider, as well as to provide enough travel
to absorb bumps and jumps.
Shock valving also has an effect on weight transfer. Refer
to shock tuning information in this chapter. Scissor stops
also affect weight transfer. See scissor stop information
also in this chapter.
Rear Scissor blocks also have a big effect on weight
transfer.
Suspension Coupling
On all Polaris snowmobile rear suspensions, there are two
torque arms that control the movement of the rail beam.
Prior to the advent of suspension coupling, these torque
arms could move independently of each other. Rear
suspension coupling links the movement of the front and
rear torque arms to each other.
The front rear scissor stop (FRSS) couples the movement
of the front torque arm with the rear torque arm and limits
the amount of independence between the movement of
the front torque arm and the rear torque arm.
When hitting a bump, the front torque arm starts to
compress. The FRSS links that movement to the rear
torque arm, causing it to compress and raise the rear
suspension up as one, allowing the suspension to hit the
bump only once and eliminating kickback. The factory
setting are usually adequate for all riders in all conditions.
The rear-rear scissor stop (RRSS) couples the movement
o the rear torque arm with the front torque arm and limits
the amount of independent movement between the rear
torque arm and the front torque arm.
Adjusting the RRSS either allows more weight to transfer
to the rear for more traction, or allows less weight to
transfer to the rear, resulting in improved cornering
performance. And adjustment dot is located on the RRSS.
This dot ID at the higher end of the scissor stop.
Moving the RRSS to a higher position will reduce weight
transfer, improve chatter bump ride and improve cornering
performance.
Rear Torsion Spring Tension Adjustment
Rear spring tension adjustments are made by rotating the
eccentric spring block. The block provides three spring
tension positions. This adjustment is easier if the long
spring leg is lifted over the roller and replaced after the
block is properly positioned. Always maintain equal
adjustment on both sides.
Torsion springs are much like coil springs, although
shaped differently. The rate of the torsion spring is
controlled by the wire diameter of the spring, and the
number of coils. Pre-load is controlled by the free opening
angle.
