Abstract: An adapter assembly for pivotable mounting of a binding to a snowboard is provided. The adapter assembly includes a first part which is adapted to be one of mounted to a snowboard and connected to a binding. A second part is rotatably connected to the first part for rotation about an axis. The second part is adapted to be the other of mounted to the snowboard and connected to the binding. The first part includes an index member having a plurality of index stops spaced at least partially around the axis. A locating member is connected to the second part which is movable from a first position, where the locating member is engaged in an index stop of the index member such that the second part is held in a rotatably fixed position relative to the first part, to a second position, where the locating member is disengaged from the index stops of the index member such that the second part is rotatable relative to the first part.