A motorcycle rack for supporting a motorcycle in a generally upright position on the bed of a truck or trailer has a main support member transversing the bed to connect to and be supported by a first and second support assembly. The motorcycle rack has one or more wheel chock assemblies on the main support member for receiving a motorcycle wheel and supporting the motorcycle while the user places restraints, when necessary, around the motorcycle. The support assemblies and/or wheel chock assemblies can include loops for securing the motorcycle. One or more moveable tie-down holds can also be placed on main support member. The support assemblies can be removably mounted on the sidewall of the vehicle using a side member and clamp or mounted to the bed using a leg and receiver combination. Cradling or clamping wheel chock assemblies can be utilized to cradle or clamp the motorcycle's wheel.