Crankshaft assemblies for vehicle assemblies, such as engine assemblies, and methods of manufacturing crankshaft assemblies are provided. The crankshaft assembly includes a first crankpin disposed between a first pair of webs and at least a first main bearing journal connected to the first pair of webs, wherein at least one of the first crankpin, the first pair of webs or the first main bearing journal is a polymeric composite including a polymer and a plurality of reinforcing fibers.