A ski includes an elongated ski body having a bottom layer defining a bottom surface of the ski, a top layer defining a top surface of the ski, and a middle layer disposed between the bottom layer and the top layer, in which the middle layer includes a negative Poisson's ratio (NPR) foam material having a Poisson's ratio of between 0 and −1.

A two-stroke engine comprises a first oiling system and a second oiling system. The first oiling system includes a low-pressure pump that distributes oil from a first oil tank to the two-stroke engine. The second oiling system includes a pump mechanically coupled to a crankshaft of the two-stroke engine, wherein the pump distributes oil from a second oil tank to an accessory at a pressure greater than the first oil pressure, wherein oil distributed to the accessory is returned to the second oil tank.

A two-stroke engine comprises a first oiling system and a second oiling system. The first oiling system includes a low-pressure pump that distributes oil from a first oil tank to the two-stroke engine. The second oiling system includes a pump mechanically coupled to a crankshaft of the two-stroke engine, wherein the pump distributes oil from a second oil tank to an accessory at a pressure greater than the first oil pressure, wherein oil distributed to the accessory is returned to the second oil tank.

A vehicle including a chassis; a seat; a motor; an endless drive track; a suspension assembly supporting the endless drive track. The suspension assembly includes at least one slide rail and at least one suspension arm pivotally connected to the slide rail and the chassis, the arm including a top bar extending laterally and a shock absorber. A first support assembly connecting a first end portion to a first chassis side and a second support assembly connecting a second end portion to a second chassis side. Each support assembly includes a bracket connected to the chassis at a top portion of the bracket; and a connector disposed on an end portion of the top bar, the connector including an arm portion, the end portion extending through a connector passage, and a flange portion defining a slot therein, a bottom portion of the bracket being received in the slot.

A vehicle including a chassis; a seat; a motor; an endless drive track; a suspension assembly supporting the endless drive track. The suspension assembly includes at least one slide rail and at least one suspension arm pivotally connected to the slide rail and the chassis, the arm including a top bar extending laterally and a shock absorber. A first support assembly connecting a first end portion to a first chassis side and a second support assembly connecting a second end portion to a second chassis side. Each support assembly includes a bracket connected to the chassis at a top portion of the bracket; and a connector disposed on an end portion of the top bar, the connector including an arm portion, the end portion extending through a connector passage, and a flange portion defining a slot therein, a bottom portion of the bracket being received in the slot.

Drive units for electric vehicles are provided. One example provides a drive unit for an electric vehicle including a first housing section forming a first compartment to house an electrical inverter and a second housing section forming a second compartment to house an electric motor. The drive unit housing further includes an inlet port to receive a fluid and a shared wall separating the first compartment and the second compartment. The shared wall defines fluid pathways in fluid communication with the inlet port to circulate the fluid to cool the electrical inverter. The drive unit also includes an outlet port in fluid communication with the fluid pathways to discharge the fluid.

Drive units for electric vehicles are provided. One example provides a drive unit for an electric vehicle including a first housing section forming a first compartment to house an electrical inverter and a second housing section forming a second compartment to house an electric motor. The drive unit housing further includes an inlet port to receive a fluid and a shared wall separating the first compartment and the second compartment. The shared wall defines fluid pathways in fluid communication with the inlet port to circulate the fluid to cool the electrical inverter. The drive unit also includes an outlet port in fluid communication with the fluid pathways to discharge the fluid.

A vehicle is disclosed that includes various portions for carrying a rider and operation of the vehicle. The vehicle may be configured for operation of more than one surface or surface type. The vehicle has a selected suspension assembly for operation of various surface types.

A chisel nut for use in improving traction of a ground engaging drive element of a vehicle includes a body having a first end for engaging the ground engaging drive element and a second end disposed opposite the first end. A chisel face is defined on a side of the body spaced a distance from the first end and extending to an edge at the second end of the body. The chisel face sized and configured to extend outward from the ground engaging drive element beyond lug members of the ground engaging drive element. A hole is defined in the body about a longitudinal axis and extends from an opening at the first end of the body toward the second end of the body. The hole includes a threaded portion for threadingly engaging with a threaded portion of a cooperatively sized fastener positioned in the hole.

A method for operating an electric vehicle has the steps of: determining if at least one of a speed of the vehicle and a speed of an electric motor of the vehicle is zero; in response to the at least one of the speed being zero, determining if a reverse actuator is actuated; in response to the reverse actuator being actuated, starting a timer, then determining if the reverse actuator has been actuated without interruption for a predetermined amount of time; in response to the reverse actuator having been actuated without interruption for the predetermined amount of time, changing an operation mode of the electric motor from one of a forward mode and a reverse mode to another of the forward mode and the reverse mode. An electric snowmobile and other methods for operating an electric vehicle are disclosed.