All of the mass (the extra links) will rest at the bottom sprocket and will balance both sides out and thus no motion...
Also the way this is shown the links would all expand straight and droop far below the bottom sprocket.
-- edited --
ok so apparently I missed the point that there are walls which keep the links from falling out of alignment. In that case theoretically it could work I suppose. Would be a fun project to experiment with.
edit on 6-1-2012 by Gruffly because: (no reason given)



