Esto dice al respecto el libro "Tupolev Tu-160 - The Russia`s Answer to the B-1" de Yefim Gordon:
"A curious feature of the Tu-160's wing design is that the innermost portions of the outer wing trailing edges, together with the triangular segments of the inboard flap sections, hinge upwards as wing sweep is increased to form a sort of boundary layer fence at maximum sweep. This feature optimises the flow around the inner/outer wing joint at high speed while obviating the need to have the outer wing trailing edges slide inside the wing gloves, an area which is quite tricky to seal in order to minimise drag."