Snowmobile Polaris EDGE / WIDETRAK (2007-2012 year). Manual - part 52

8.10

Steering and Suspension Systems

9923396 - 2007-2012 EDGE/Widetrak LX Service Manual

Toe Adjustment

Toe is adjusted with the shocks and skis installed. Track
alignment must be correct before starting this process.

Toe alignment is measured at ride height.

Lift front of the machine off the floor rock the front end
up and down and then set it down gently. This will set
the unit at ride height.

Measure and make a mark 10” (2.54cm) forward of
the ski mount bolt and 10” (2.54cm) behind the ski
mount bolt, preferably on the center line of the carbide
skags.

Place a straight edge along the one side of the track.
Make sure that the straight edge is touching along the
length of the track.

Record the measurements from the edge of the
straight edge to the forward ski mark and the rearward
ski mark.

Adjust the tie rod so that the toe is set per the
specifications.

Place the straight edge on the opposite side of the
track and measure the opposite ski marks.

Adjust the tie rod so that the toe is set per the
specifications.

Verify that the ski center distances are within
specification from the forward marks and the rearward
marks.

REAR SUSPENSION

Operation

The primary function of the rear suspension is to provide
a comfortable ride in all types of riding conditions. It
separates the rider from the ground, while allowing for
complete vehicle control. The rear suspension also must
provide weight transfer and maintain track tension.

The rear suspension has many adjustable features for fine
tuning to achieve optimum comfort. The suspension can
be adjusted to suit rider preference and deliver excellent
performance for a given set of conditions. It should be
noted, however, that suspension adjustments involve a
compromise or trade off. A machine set up to perform well
in the moguls would not suit the preference of a groomed
trail rider.

Weight Transfer

The shifting of weight from the skis to the track is called
weight transfer. As engine torque is applied to the drive
axle the torque is transferred to the track, pulling it forward.
This energy also tries to pull the suspension forward. The
front torque arm reacts to this force by pushing down on
the front of the track, in effect applying more weight to the
front of the track and reducing the weight on the skis. It is
important to note that energy used to lift the front of the
machine is not available to push the vehicle forward.

Changing the angle of the front torque arm changes the
suspension's reaction to the force. Adjusting the length of
the limiter strap will change the front torque arm angle.
Shortening the strap limits the extension of the front of the
suspension; reducing the angle of the torque arm and
increasing ski pressure during acceleration. Lengthening
the strap allows the front of the suspension to extend
further; increasing the angle of the torque arm and
decreasing ski pressure during acceleration. Limiter strap
adjustment has a great affect on weight transfer. Limiter
straps only affect acceleration. It is important to check
track tension whenever limiter strap length is changed.

Front track shock spring preload also affects weight
transfer. A stiffer spring and/or more preload on the spring
transfers more weight to the track. A softer spring and/or
less preload keeps more weight on the skis. Keep your
riding application in mind when choosing springs and
setting spring preload. Soft springs/preload will increase
ski pressure, but may bottom out. Stiff springs/preload will
provide more track pressure (reduced ski pressure), but
may result in a less comfortable ride

8.11

Steering and Suspension Systems

9923396 - 2007-2012 EDGE/Widetrak LX Service Manual

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.

8.12

Steering and Suspension Systems

9923396 - 2007-2012 EDGE/Widetrak LX Service Manual

REAR TRACK SHOCK CONTROL
RODS

Edge Shock Rods

Shock rods must be installed in the same orientation as set
from the factory. Any changes made to the shock rod

orientation other than the factory setting may cause

suspension damage.

.63" (16 mm)

.45" (11.4 mm)

Lower

Upper

Trail RMK (lower end is smaller than the upper end)

340-, SuperSport (both ends are the same size)

.475" (12 mm)

Facing Shock

Shock Rod Assembly Example (Trail RMK Shown)

Shock

Lower

Upper

8.13

Steering and Suspension Systems

9923396 - 2007-2012 EDGE/Widetrak LX Service Manual

REAR SUSPENSION ADJUSTMENTS

Adjustment Procedures

It is a recommended to break the suspension in for
approximately 150 miles (240 km) before fine tuning
adjustments are made.

All settings will vary from rider to rider, depending on rider
weight, vehicle speed, riding style, and trail conditions. We
recommend starting with factory settings and then
customizing each adjustment individually to suit rider
preference. The machine should be methodically tested
under the same conditions after each adjustment (trail and
snow conditions, vehicle speed, riding position, etc.) until
a satisfactory ride is achieved. Adjustments should be
made to one area at a time, in order to properly evaluate
the change.

The purpose of the front rear scissor stop (FRSS) is to
control the bump attitude of the rear suspension. As the
front torque arm (FTA) hits the bump, it forces the rear
scissor to collapse a predetermined amount, depending
on the FRSS block position.

This accomplishes two important things, it allows a lighter
spring rate on the FTA because it can borrow spring rate
from the rear torsion springs; and it prepares the rear
portion of the suspension for the bump, reducing
secondary kick back.

The FRSS is made of a resilient material allowing smooth
action and preventing any suspension component
damage.

Setting the Rear Suspension Ride Height

To set up the rear suspension torsion spring preload,
measure the distance between the ground and rear
bumper with out the rider on the seat and the
suspension at full extension. This can be achieved by
lifting the rear of the machine so that the suspension
is off the ground and carefully setting the machine
down. Write this down as measurement “X”.

Have the rider in full gear drop down on the seat, work
the suspension slightly by bouncing up and down and
sit in the seated riding position. With the rider in the
seated position measure from the ground to the
bumper in the same spot as you did for measurement
“X” and write it down as measurement “Y”.

To determine the correct ride height, subtract
measurement X from measurement Y. (X - Y = ride
height).

The ideal ride height is:

• EDGE RMK / EDGE = 4” (10cm)

• Widetrak = 1.5” (4cm)

Adjust for the desired ride height by rotating the
torsion spring cams located on the rear of the torsion
spring.

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