Arctic Cat Sno Pro 120, Service Manual

Page: 352 / 470

7-2
Suspension

NOTE: Whenever a part is worn excessively,
cracked, or damaged in any way, replacement is nec-
essary.
SPECIAL TOOLS
A number of special tools must be available to the techni-
cian when servicing the rear suspension.

NOTE: Special tools are available from the Arctic
Cat Service Parts Department.
UNDERSTANDING THE SUSPENSION
Quick acceleration and the ability to go through the turns
with power are the most important handling qualities.
This section explains how the skid frame functions to
provide these two important handling qualities. Before
proceeding, however, note these terms.
Weight Transfer — A shift in the center of gravity in
any direction depends on the force applied.
Track Tension — The amount of tightness or looseness
of the track when correctly mounted in the chassis.
Spring Tension — The amount of force exerted on the
spring by either fork tension adjustment or eyebolt
adjustment.
Ski Pressure — The amount of force exerted downward
on the skis.
Good weight transfer characteristics are needed for fast
acceleration (shift of weight from skis to track) and for
cornering (shift of weight back to skis to hold the front
end in turns). Effective weight transfer depends on sus-
pension tension, position of rider, and the position of the
front arm limiter.
To understand how the suspension system works, think
of the entire system in terms of three points; the skid
frame rear axle center, the skid frame front arm, and the
ski saddle center.
Assume that the front arm functions as a stationary pivot
point between the rear axle center and the ski saddle cen-
ter. Also assume that the ski saddle center is the same
height off the ground as the rear axle center. This pro-
duces the standard position arrangement.
0728-180
Under acceleration when the center of gravity is trans-
ferred to the rear of the machine, the rear suspension col-
lapses slightly. This brings the rear arm point downward
and with the front arm stationary, the teeter-totter effect
reduces the pressure on the skis, position A.
However, for controlled cornering, more pressure is
needed on the skis. So when the driver decelerates com-
ing into a corner, the center of gravity is transferred for-
ward, putting the required pressure onto the skis and
reducing the pressure on the rear suspension, position C.
0728-181
This is essentially what weight transfer is all about — the
shift of weight to the rear of the machine for positive
traction and good acceleration or to the front of the
machine for positive handling and cornering control.
Suspension Setup Basics
SKI SHOCK ABSORBER SPRINGS
The shock absorber springs have been matched to the
shock valving and rear suspension. These springs are the
result of hours of testing and comparison riding trying
many different combinations of springs and shocks. If
changes are necessary, several spring and shock sizes are
available. While making these changes, keep the follow-
ing points in mind.
Heavier Or Stiffer Springs
1. These will require shocks with more rebound con-
trol, or the front end will become like a pogo stick.
Description p/n
Shock Absorber Air Pump 2603-614
Piston Location Tool 0644-169
Idler Wheel Puller Kit 0644-570
Inflation Needle 0744-020
Rear Suspension Spring Tool 0144-311
Gas Shock Retaining Blocks (Zero Pro) 0644-486
Spanner Wrench - Fox Float Shock
0744-072
Handlebar Stand 5639-152
Steering Post Stand 5639-946
Bearing Cap Seal Protector 0644-268
Floating Piston Location Gauge 0644-350