Suspension SPECIAL TOOLS
A number of special tools must be available to the technician when servicing the rear suspension. NOTE: When indicated for use, each special tool will be identified by its specific name, as shown in the chart below, and capitalized. 0728-180/181
Description Shock Absorber Air Pump Idler Wheel Puller Kit Rear Suspension Spring Tool Handlebar Stand Steering Post Stand
p/n 2603-614 0644-570 0144-311 5639-152 5639-946
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 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. 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.
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. 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 following points in mind. Heavier or Stiffer Springs
1. These will require shocks with more rebound control, 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 acceleration and can cause the rear shocks and spring to bottom out. 3. If the springs are too stiff for general riding conditions 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 deceleration, 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.
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.
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