Snowmobile Arctic Cat (2002 year). Manual - part 131

9-2

UNDERSTANDING THE SUSPENSION

GENERAL

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 loose-

ness of the track when correctly mounted in the chas-

sis.

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 down-

ward 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 suspension 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 center. Also assume that the ski saddle center is

the same height off the ground as the rear axle center.

This produces 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

collapses slightly. This brings the rear arm point

downward and with the front arm stationary, the tee-

ter-totter effect reduces the pressure on the skis, posi-

tion A.

However, for controlled cornering, more pressure is

needed on the skis. So when the driver decelerates

coming into a corner, the center of gravity is trans-

ferred forward, 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 posi-

tive traction and good acceleration or to the front of

the machine for positive handling and cornering con-

trol.

9-3

9

SUSPENSION SETUP BASICS

FRONT ARM SPRING TENSION

„

NOTE: Read the following information closely as

it pertains to all suspensions used in the last sev-
eral years. If there are any questions, please con-
tact the Arctic Cat Service Department.

It is desirable to run with very light front arm spring

tension. When riding in 4 in. or more of snow, the

machine will be quicker if the front spring tension is

adjusted lightly.

If the spring tension is adjusted too stiff, the track

angle at the front of the skid frame is steep. This steep

angle prevents the snowmobile from getting up on

plane and slows down by 5 to 8 mph.

When riding in sticky snow (springtime or warm days)

or hill climbing on hard snow, it may be desirable to

stiffen the front arm spring tension. When this is done,

weight is transferred back quicker. The problem with

too much front arm spring tension is that the feel of the

snowmobile becomes very short. The reason for this is

the front arm becomes the pivot point between the

spindles and rear of the machine. With dominant

spring tension on the front arm, the suspension is basi-

cally contacting the snow from a point below the front

arm to the skis or the spindle pressure point. This

makes for a very short and darting machine on the

trail. This is especially true when decelerating and the

center of gravity is transferred forward.

A good method for adjusting the front spring tension

follows.

„

NOTE: On those models having a coil spring

over the front arm shock absorber, the spring ten-
sion should be set as soft as possible when oper-
ating on trails and in deep snow.

0729-662

FRONT ARM LIMITER STRAPS

Under no circumstances should the front arm limiter

strap be lengthened. If lengthened, it may cause shock

absorber travel problems.

The two limiter straps on AWS models can be short-

ened if desired. This adjustment must be made to suit

driving style and some test driving time. With the rear

arm in its present mounting location, no advantage has

been noted from changing the strap length. If the front

arm straps are shortened, the result will be more ski

pressure and aggressive steering.

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 there is a need to make changes, there are

several spring and shock sizes to choose from. While

making these changes, keep the following 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.

2. With stiffer springs, the front end will become

more aggressive in the corners as more weight will

be transferred to the skis when decelerating. Also,

more weight is transferred to the rear on accelera-

tion and can cause the rear shocks and spring to

bottom out.

3. If the springs are too stiff for general riding condi-

tions and style, the ride comfort is gone.

Spring Tension Too Soft

1. Front end bottoms out; hard on front end parts.

2. Less aggressive steering in corners on decelera-

tion, and less weight is transferred to the skis

because of softer springs.

3. Less weight gets transferred to rear of the machine

upon acceleration.

„

NOTE: When softening the ski springs, also

soften the rear to match entire suspension.

FRONT ARM SPRING TENSION TOO 

STIFF

1. Slows machine down in loose snow.

2. Causes the machine to dart and dive as a result of

less track on the ground on deceleration.

! CAUTION

If the ski shock spring is adjusted too loose, the
spring retainer may fall out. If the spring is
adjusted beyond specification, the spring will
coil bind and spring adjuster damage will occur.

9-4

„

NOTE: It has been our experience that a tight

front arm works well under only two conditions:
sticky snow conditions in the spring of the year
and in hill climbing on hard packed snow.

It has also been our experience with AFS models that

with the front arm adjusted too soft, the spring may

come off the roller. There haven't been any other prob-

lems in handling caused by a soft front arm.

REAR ARM SPRING TENSION

The rear spring tension is adjusted for the weight of

the driver. There are three possible adjustments.

1st block position - set for up to 150 lb

2nd block position - set for 150 to 200 lb

3rd block position - set for over 200 lb

727-720A

REAR ARM MOUNTING POSITION

(Between Rails)

For 2002, there are several mounting holes found in

the rails for installing the rear arm.

The holes have been added to the suspension to pro-

vide adjustment to fine-tune the suspension to driving

styles.

If the ride is too soft, moving the rear arm back

between the rails will stiffen the ride. By moving the

rear arm forward, it will collapse quicker and allow

more transfer of weight to the back of the suspension.

This will also affect the handling by providing a softer

ride and also easier steering.

„

NOTE: Please add the third hole to any FasTrack

suspension on 1994 through 1997 models. It can
easily be done by drilling a 3/8 in. hole 3/4 in.
behind the last hole in the rails.

0730-847

The drawbacks of moving the rear arm forward are

that the suspension may bottom out quicker and some

travel is lost.

0728-038

„

NOTE: When making any changes to the front or

rear suspension, the change should be made at
both ends to keep the suspension balanced. For
example, installing stiffer springs in front may
require installing the next step stiffer spring in
back to keep everything in balance.

WISH BONE ARM SUSPENSION 

(All Models with

Rubber Mounting Bushings)

Proper setup on the AWS style front-end assembly

with rubber mounting bushings starts by making sure

the wishbone arms are parallel. To check, follow the

procedure below.

1. Lift the front-end assembly high enough so the

skis are off the floor. Place a support under the

belly pan.

2. Remove both shock absorbers.

3. Standing in front of the machine, view the wish-

bone arms to see if they are parallel with the chas-

sis. If they are not level, proceed to step 4.

4. Lift each ski assembly separately until it is level or

parallel, then place a support (block of wood)

under the ski to hold arms parallel.

5. Remove the exhaust pipe.

! CAUTION

The rear arm mounting position between the rails
on all 1998 Panther models must remain in the
rear mounting hole. If the arm is moved forward,
rear arm and rear shock damage will occur.

9-5

9

6. Loosen the four bolts securing the upper and lower

wishbone arms to the front end assembly.

0729-883

7. Lift each ski assembly to maximum travel and set

back down on support. Standing in front, check

once again to make sure arms are parallel.

8. Tighten the four bolts securing the two arms on

each side to 9.7 kg-m (70 ft-lb).

9. Install the shock absorber making sure to tighten

the two mounting bolts.

„

NOTE: The above procedure is not required on

AWS front-end assemblies having solid bushings
in the A-Arms. The bolts should be checked for
proper torque on these models.

10. Install the exhaust pipe.

„

NOTE: It is important that the ski tips are slightly

elevated. Preloading the skis in the slightly
upward position enhances the handling character-
istics of the snowmobile.