I worked out how to have one or more drop down menus without changing code. It seems that when creating a menu you create & name your menu, then assign placeholders as required, placeholders being the top of your menu ( for example bicycles brands as placeholder, then colnago, bianchi etc as the parts ( pages ) of the dropdown menu ) then have all your pages within the menu and then drag the pages underneath the appropriate placeholders finally assigning as primary menu.