Polaris SUPERSPORT 2006, Manual

Page: 218 / 300

11.2
REAR SUSPENSION
REAR SUSPENSION
SPECIFICATIONS
MOUNTING TORQUE SPECIFICATIONS
3/8
”
top shock mounting bolts........28-30 ft. lbs. (39 - 41 Nm)
3/8
”
suspension mounting bolts....35 - 40 ft. lbs. (49 - 55 Nm)
7/16
”
suspension mounting bolts...55 - 60 ft. lbs. (76 - 83 Nm)
Shock rod bolts(do not over torque)*Shock rods must pivot
freely after torquing...................................12 ft. lbs. (17 Nm)
REAR SUSPENSION
OPERATION
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
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.
see “SCISSOR STOP ADJUSTMENTS” on page 11.4.
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