Systems, vehicles, and assemblies that include an prime mover, a transmission, and a coupler. The coupler couples the prime mover and the transmission. A preferred embodiment includes a system for forming a rigid body that includes a rotational prime mover and a transmission assembly. The transmission assembly transmits at least a portion of the rotational energy from the prime mover to a driven member at a frequency. The system includes a first and a second bridging member. Coupling the first bridging member to the second bridging member forms a symmetric bridge or coupler. The symmetric bridge is symmetric about a first plane of symmetry. Furthermore, coupling a first portion of the bridge to the rotational prime mover and coupling a second portion of the bridge to the transmission assembly forms the rigid body. The rigid body further includes the bridge.