A tank holding frame for a vehicle body includes front and rear beams connected to the vehicle body, a first beam connected to the vehicle body and the front beam, a second beam connected removably to the vehicle body, and a guard member having at least one end connected removably to a respective one of the first and second beams. A fuel tank is removable from a tank holding space cooperatively defined by the front, rear, first, second beams, the guard member, and the vehicle body when the second beam and the guard member are detached from the tank holding frame.