Abstract: Snowmobile skis include at least one elongated wing member projecting laterally outward and upward from a lateral side of a base portion of the ski. The at least one elongated wing member has a lower surface that extends vertically over and laterally outward from a lower running surface of the ski. At least a longitudinal section of the lower surface of the at least one elongated wing member may include a portion having a curved, concave shape. The lower surface of the at least one elongated wing member may extend a greater distance vertically over the lower running surface of the ski near a longitudinal midportion of the ski relative to a distance by which the lower surface of the at least one elongated wing member extends vertically over the lower running surface of the ski near a longitudinal front portion of the ski and near a longitudinal rear portion of the ski.

Abstract: Snowmobile skis include at least one elongated wing member projecting laterally outward and upward from a lateral side of a base portion of the ski. The at least one elongated wing member has a lower surface that extends vertically over and laterally outward from the lower running surface of the ski. At least a longitudinal section of the lower surface of the at least one elongated wing member may include a portion having a curved, concave shape. The lower surface of the at least one elongated wing member may extend a greater distance vertically over the lower running surface of the ski near a longitudinal midportion of the ski relative to a distance by which the lower surface of the at least one elongated wing member extends vertically over the lower running surface of the ski near a longitudinal front portion of the ski and near a longitudinal rear portion of the ski.

Abstract: A snowmobile ski with a pair of outboard keels and laterally projecting, upwardly slanting, lateral wings attached proximate the outboard keels is disclosed. A ski of this structure has improved flotation and resistance to side slippage in turns.

Abstract: A snowmobile ski with a pair of outboard keels and laterally projecting, upwardly slanting, lateral wings attached proximate the outboard keels is disclosed. A ski of this structure has improved flotation and resistance to side slippage in turns.

Abstract: This invention relates to an improved snowmobile ski having a vertical fin on the topside of the ski with a surface area large enough to minimize or prevent sideways slippage of the ski during a turn. The fin, if a single fin is used, is located adjacent the outboard edge of the ski. A snowmobile ski with dual topside fins having outwardly projecting lips along the upper edges of said fins has improved performance in deep snow.

Abstract: A snowmobile ski with a pair of outboard keels and laterally projecting, upwardly slanting, lateral wings attached proximate the outboard keels is disclosed. A ski of this structure has improved flotation and resistance to side slippage in turns.

Abstract: This invention relates to an improved snowmobile ski having a vertical fin on the topside of the ski with a surface area large enough to minimize or prevent sideways slippage of the ski during a turn. The fin, if a single fin is used, is located adjacent the outboard edge of the ski. A snowmobile ski with dual topside fins having outwardly projecting lips along the upper edges of said fins has improved performance in deep snow.

Abstract: This invention relates to an improved snowmobile ski having a vertical fin on the topside of the ski with a surface area large enough to minimize or prevent sideways slippage of the ski during a turn. The fin, if a single fin is used, is located adjacent the outboard edge of the ski. A snowmobile ski with dual topside fins having outwardly projecting lips along the upper edges of said fins has improved performance in deep snow.

Abstract: A snowmobile ski with a pair of outboard keels and laterally projecting, upwardly slanting, lateral wings attached proximate the outboard keels is disclosed. A ski of this structure has improved flotation and resistance to side slippage in turns.

Abstract: Described is an adjustable side rail having a first elongate rail portion, a second elongate rail portion, and a tab projecting from one end of one of the first and second elongate rail portions. The second elongate rail portion has spatially separated opposing upper and lower grooves. Each groove slidingly receives one of the top and bottom edges of the first elongate rail portion when the first elongate rail portion engages the second elongate rail portion. The tab has a side edge with a notch formed therein for catching an edge of a hole in a mounting rail into which the tab is inserted and for anchoring the one end of that elongate rail portion to the mounting rail while a length of the side rail is adjusted.

Abstract: Described is a fastener that includes a shank having a thread, a head, and a stepped portion situated between the head and the threaded portion. The stepped portion has a diameter that is larger than the diameter of a round hole in a first type of mounting rail and smaller than a length of a side of a square hole in a second type of mounting rail. When the fastener is inserted into a round hole, the stepped portion is urged against a front surface of the mounting rail. When the fastener is inserted into a square hole, the stepped portion enters closely into the square hole and the head portion is urged against the mounting rail. Accordingly, the fastener can be used with either of two types of mounting rails: Universal Mounting Rails and EIA Standard Mounting Rails.