The term 'Roadies' Loads' refers to the equipment that is carried by roadies, which are people who work in the music industry and are responsible for setting up and taking down equipment for concerts and other events. The four-letter solution to this crossword is AMPS, which stands for amplifiers. Amplifiers are an important piece of equipment for musicians, as they increase the volume of sound coming from instruments or microphones. Roadies are responsible for carrying and setting up these amplifiers, as well as other pieces of equipment, for concerts and other events.