Under acceleration when the center of gravity is transferred 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 teeter-totter effect reduces the pressure on the skis (position A).
Suspension NOTE: Whenever a part is worn excessively, cracked, or damaged in any way, replacement is necessary. SPECIAL TOOLS
A number of special tools must be available to the technician when servicing the rear suspension. Description Shock Absorber Air Pump
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 transferred forward, putting the required pressure onto the skis and reducing the pressure on the rear suspension (position C).
p/n 2603-614
Shock Absorber Air Pump (Dual Digital)
0641-257
Idler Wheel Puller Kit
0644-570
0728-181
Rear Suspension Spring Tool
0144-311
Handlebar Stand
5639-152
Steering Post Stand
5639-946
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.
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 eye bolt 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 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
126
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 following points in mind: Heavier/Stiffer Springs
1. These will require shocks with more rebound control, or the front end will become like a pogo stick. 2. Less aggressive steering in corners on deceleration, and less weight is transferred to the skis because of softer springs. 3. Less weight gets transferred to the rear of the snowmobile upon acceleration. NOTE: When stiffening the ski shock springs, also stiffen the rear to match entire suspension. Spring Tension Too Soft
1. Front end bottoms out; hard on front end parts. 2. With softer 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 acceleration and may can cause the front arm shock and spring to bottom out.
