Sunday could be a busy day:
The Society for Industrial Archaeology is sponsoring a walking tour of the industrial heritage of Williamsburg & Greenpoint (starting time 1PM). Afterwards, the Municipal Art Society is sponsoring a tour of Greenpoint & Williamsburg (starting time 4:30), led by Francis Morrone. Details on both tours here.
Bar Matchless and Works Engineering are putting on all day Vintage European and Japanese Motorcycle Show – the bike show runs from 10AM to 5PM; music from 5PM to 7PM. There’ll be free food and free beer too. Details here and here.
Its certainly possible to do all three.