Abstract: A suspension system includes a swing arm having an end engaging a framework of a vehicle, an end engaging skid rails for a track. A front link has an end engaging the framework and a second end. The first end engages. A middle link has a end joined to the second end and a front portion of the swing arm, and a shock end. A shock has a end joined to the shock end, and a rail end engaging the skid rails. The front link, middle link and shock enable a rising rate system. A rear arm has an end engaging the framework, an end engaging a rear portion of the skid rails, and a length approximately a length of the swing arm. The rear arm is positioned approximately parallel to the swing arm during a travel range of the suspension system for controlling an orientation of the skid rails.