US Patent 7360618 Snowmobile track suspension

A snowmobile track suspension is disclosed. The track suspension includes a chassis, a skid frame, a front arm, an idler arm, and a rear arm. The chassis includes a tunnel. The skid frame includes rails along which the track rides. The front arm has a forward end pivotally and slidably connected to the tunnel. The front arm also includes a rearward end pivotally connected to the rails. The idler arm includes a forward end pivotally connected to the tunnel and a rearward end connected to the rear arm. Such connection is at the upper end of the rear arm, with the lower end of the rear arm pivotally coupled to the rails.