A sports boot comprising a part comprising at least two superposed layers of plastics and comprising an opening that can be closed by catching means distributed on either side of this opening, wherein one of the two layers has one or more recesses lying on an axis in order to define a deformation axis of the shell, allowing that part of the shell that is around this axis to move away in order to enlarge the opening and make it easier to put the boot on and to take it off.