New Arctic Cat “Cross-Link” Rear Suspension
Winter 2000 - 2001

All three of the 2001 ZR race sleds feature the latest version of the Fastrack rear suspension fitted with the new “Cross-Link” shock design. An oil line between the shocks in the rear suspension allows sharing of shock oil, providing all of the benefits of “communication” and two-way coupling. That includes reduced ski lift, pitch control, reduced kickback, and all of the ride quality improvements.

In effect, the Cross-Link provides the rear-to-front coupling that Arctic Cat has been missing. And in typical Arctic Cat fashion, instead of equaling existing designs, they appear to have leap-frogged them. This system is different; all other coupled suspensions utilize some form of physical stopper to provide the coupling effect. Cat is the first to produce a hydraulic coupler.

The Cross-Link was the result of several years of development, first pursued by Team Arctic’s Kirk Hibbert. Kirk first conceived the idea, and built the first version back in ’96. That attempt was shelved for a while, but pulled back out for more development in ’97. The early versions worked very well in rougher ice racing conditions, but even Kirk admits it didn’t work that well in snow cross; yet. Continued development through the race seasons found the design being tested and developed, until last season it was used by his son Tucker Hibbert at every race except Spirit Mountain. Yes, the Cross-Link suspension was in Tucker’s sled when he won the X-Games.

Did you notice the holeshot Tucker had off the line at the X-games? One of the objections to coupled suspensions has traditionally been the lack of weight transfer and resulting acceleration. According to Hibbert, the Cross-Link allows the front arm to be extended 1/2” to 1” further, which places more track on the ground. With more track on the ground in comparison to the un-coupled skid frame, the result is more traction. Even though the hydraulic coupling limits weight transfer, it does not take away from the holeshot. Hibbert stated that having the skis only slightly off the ground is more desirable than having them dangle. Once the weight transfers to the track and the skis are un-loaded, it doesn’t matter if the skis are 1/4” off the ground or higher; the acceleration then becomes a function of traction.

Perhaps the most exciting feature of all 2001 Sno Pro race sleds is the new Arctic Cat “Cross-Link” rear suspension. An oil line between the rear shocks allows sharing of shock oil, providing hydraulic coupling to the skid frame. Ride quality and pitch control are improved, along with a reduction in ski lift.

How does it work? Arctic Cat already had their hydraulic front arm adjust, which places shock oil on the backside of the adjuster piston in comparison to “normal” shocks. When the rear shock sees forces of compression (from acceleration or a tail landing) it displaces the oil from the rear shock into the front shock. The system is really only sending oil from the rear to the front and back again, so it is more of a rear-to-front coupling device than it is a front-to-rear coupler, as the cross shaft in front of the rear arm is still in place providing some front-to-rear coupling.

Hibbert tells SnowTech that the hydraulic coupler acts different than the mechanical couplers in that it’s not as solid. Where a physical stopper provides an abrupt transition from an un-coupled state to a fully-coupled state, the hydraulic coupler is much more progressive in nature. The coupling starts immediately and progressively, and can be “tuned” by design for a faster or slower rate of progression and provides a more linear force vs. displacement curve. Incredible.

Rear Shock Compression

Arctic Cat already had their hydraulic front arm adjust, which places shock oil on the backside of the adjuster piston in comparison to “normal” shocks. When the rear shock sees forces of compression (from acceleration or a tail landing) it displaces the oil from the rear shock into the front shock. The system is really only sending oil from the rear to the front and back again, so it is more of a rear-to-front coupling device than it is a front-to-rear coupler, as the cross shaft in front of the rear arm is still in place providing some front-to-rear coupling

Rear Shock Extension

The ride quality of the Cross-Link suspension indicates a widened performance envelope. A firm Snow Cross calibration is able to provide more small-bump compliance at lower speeds than before. The Cross-Link maintains more traction (due to the greater front arm pressure allowed by the longer limiter settings) yet a plusher ride. Calibration tweaks that were previously altered to achieve a desired balance are now back on the table as tunable items thanks to the benefits from the Cross-Link.

Perhaps the larger benefit is the reduction of pitching. With two-way communication now occurring between the shocks, they borrow spring & shock rate from each other, but also keep the rails more parallel to the ground that reduces the “rocking” or pitching action through bump courses. The coupling action helps to maintain a parallelogram by controlling rail angles.

Hibbert also believes there is some valving communication occurring in addition to the rail angle control. The suspension asks for a stiffer front arm spring, yet a softer rear arm spring. This allows for the softer ride at lower speeds yet maintains the big-bump performance. The shocks are identified as Arctic Cat Technology (ACT) shocks, but they also have a small “Dynamic” insignia on them. This indicates they are being supplied to Arctic Cat by automotive race-shock manufacturer Dynamic, built to Arctic Cat specifications.

While the Cross-Link rear suspension is currently found on the three ZR Sno-Pro race sleds, we expect Arctic Cat calibration engineers will be working on trail calibrations for future Arctic Cat trail sleds.