Abstract: A ventilating wheel provides a plurality of angled vanes extending from a hub. The ventilating wheel secures to the slide rail of a snowmobile suspension system. An endless track extends over the underside of the slide rail. A hyfax may secure to the slide rail interposed between the track and slide rail to reduce friction therebetween. The ventilating wheel is in rolling contact with the track and is rotated thereby to draw air and snow over the slide rail. In some embodiments, air and snow flow over the radiator is induced. The ventilating wheel may serve as an idler wheel defining the shape of the track. In other embodiments, the ventilating wheel mounts to a straight portion of the slide rail and serves to reduce pressure on the hyfax. In still other embodiments, the ventilating wheel serves only to increase air and snow circulation.

Abstract: A snowmobile ski having improved turn stability. The ski includes a lower surface for sliding contact with snow, the lower surface being configured with at least one longitudinally extending, downwardly open groove having an internal cross-section dimension that diminishes rearwardly to thereby progressively constrict the groove. The groove is open forwardly to receive snow within it and is open rearwardly to enable snow to exit from the groove. Snow received within the groove becomes packed when such snow encounters the progressively constricted portions of the groove as the ski slides forwardly on a snowy surface.