A rear portion of a ski
mountaineering binding (1), wherein: it comprises a base (2, 3); it comprises a
turret (5, 6) which is rotatable in order to assume a first
turret position (T1), wherein it is fixable to the
heel (7) of a ski boot to enable skiing downhill, and in order to assume a second
turret position (T2) for walking uphill; it comprises a
brake (8, 81, 82, 83, 84, 85, 86, 87, 88, 89) for a ski (4); the
brake (8, 81, 82, 83, 84, 85, 86, 87, 88, 89) comprises a braking lever (8) which is rotatable to assume a braking position (PF) and a non-active position; the
brake (8, 81, 82, 83, 84, 85, 86, 87, 88, 89) comprises first elastic means for acting on the braking lever (8) for rotating the braking lever (8) towards the braking position (PF); the braking lever (8) is arranged so as to be pressed by the
heel (7) of the ski boot, when the turret (5, 6) is in the first turret position (T1), in order to reach the non-active position (PD); it comprises a rotation member (9) which is rotatably borne by the base (2, 3) and which in turn bears the braking lever (8); it comprises connecting means (31, 32, 33, 35, 37) which connect the rotation member (9) and the turret (5, 6) to one another so that the rotation member (9) and the turret (5, 6) are solidly constrained to one another, when the turret (5, 6) is in the second turret position (T2) and when the braking lever (8) is in the non-active position (PD), so that it is possible to walk uphill.