have a bit of a kickup at the rear .
Beyond that , the tail of the ski is the only object that has steering ability when a sled is leaned far onto its side and counter-steered ( when the rider is leaning left with the handlebar turned to the right , the tail protrudes out and down into the mountainside ). Thus , the shape of the tail is critical to keep the machine on course and dictates how much kicking or feedback will be injected to the rider when encountering firm snow while on the sled is on edge .
While the bottom of the ski rides through or on the snow and obviously affects a machine ’ s handling , the topside of the ski where it mounts to the sled and interacts with the spindle / rubber has received additional attention in recent years to optimize the ski ’ s characteristics . Even if a ski had the perfect keel , best runner , optimum profile , lightest weight and topnotch color scheme , if it isn ’ t bolted to the spindle in the most effective position with an optimized ski rubber , it ’ ll be left at the bottom of the performance pile .
Each riding terrain or snowmobile segment requires a bit different desired needs from the skis . Skis with a lot of length in front of the spindle bolt can have light steering effort . However , they are prone to over-flexing , walling upward and stopping progress when impacting firm snow transitions around mountainous treewells . This can be combated by designing a very stiff ski rubber with lots of preload between the spindle foot and top surface of the ski – and the ski must hold the rubber snuggly without letting the rubber dance free on impact .
Reducing the length of the ski that ’ s in front of the spindle or bolting the ski to the spindle further rearward will let the ski return to center or self-steer to straight when leaned more readily .
Careful selection of how tall the ski is ( from bolt to bottom of skag ) is also critical , as this will affect motion ratios of the front suspension . It essentially contributes to the height from the contact point ( the snow ) to the lower A-arm , from which suspension engineers extract all calculations for roll center , instant center , center of gravity , etc .
Thus , the design of the ski ' s top surface , including the mounting bolt location , ski rubber cavity , shape of the foot of the spindle , the presence and dimensions of reinforcing ribs , etc ., all of which doesn ’ t interact with the snow , can inject its own behavior or handling characteristics into the skis .
Many of these visible items ( keel design , bolt location , width ) are readily seen and felt when riding a snowmobile . They share design considerations downhill skis , cross-country skis and water skis , among other sports , often leveraging the same engineering principles . But even a machine we buy new right off the show floor with a stock set of skis can offer a completely different steering experience ( for better or worse ) by bolting on a set of aftermarket skis . FEBRUARY 2025 / SNOWGOER . COM / 41