Saddlemount combination. A saddlemount combination is a combination of vehicles in which a truck or truck tractor tows one or more trucks or truck tractors, each connected by a saddle to the frame or fifth wheel of the vehicle in front of it. The saddle is a mechanism that connects the front axle of the towed vehicle to the frame or fifth wheel of the vehicle in front and functions like a fifth wheel kingpin connection. When two vehicles are towed in this manner the combination is called a double saddlemount combination. When three vehicles are towed in this manner, the combination is called a triple saddlemount combination.