Abstract: The invention relates to a universal support device (4; 12; 27) for motorcycle accessories characterised by being directly fixed to the cap (1) of the motorcycle fuel tank. The support can be made by a ring nut, supports or pins, fixed to the outer crown (1a) of the cap, and fitted with anchorage means for various objects such as, for example, bags, rucksacks, suitcases, trolleys, gadgets, helmet holder sacks, containers of various kinds, motorcycle cover tarpaulins, electronic appliances, cellular telephones, video cameras, satellite navigators, anti-theft systems, etc.