A gyratory crusher outer crushing shell comprising: a main body mountable within a region of a topshell frame of a gyratory crusher, the main body extending around a central longitudinal axis; the main body having a mount surface (201,206, 207) being outward facing relative to the axis for positioning against at least a part of the topshell frame and a contact surface (200, 203, 205) being inward facing relative to the axis to contact material to be crushed, at least one wall defined by and extending between the mount surface (201, 206, 207) and the contact surface (200, 203, 205), the wall having a first upper axial end and a second lower axial end; an orientation of the contact surface extending from the first end being inclined so as to project radially inward towards the axis in the axially downward direction to define an inlet region; an axially lowermost part of the inlet region is terminated by a shoulder region, a contact surface at the shoulder region being inclined so as to project radially inward towards the axis from the contact surface of the inlet region in an axially downward direction; an angle of inclination ( a) of the contact surface of the inlet region relative to the axis is less than an angle of inclination (b) of the contact surface of the shoulder region relative to the axis; characterised in that: the crushing shell comprises a single shoulder region that terminates the inlet region, the contact surface from an axially lowermost part of the shoulder region to the second lower axial end defining a crushing face that extends immediately from the axially lowermost part of contact surface at the shoulder region, the crushing face orientated to be declined to project radially outward relative to the axis in a downward direction from the shoulder region to the second lower axial end. a main body mountable within a region of a topshell frame of a gyratory crusher, the main body extending around a central longitudinal axis; the main body having a mount surface (201,206, 207) being outward facing relative to the axis for positioning against at least a part of the topshell frame and a contact surface (200, 203, 205) being inward facing relative to the axis to contact material to be crushed, at least one wall defined by and extending between the mount surface (201, 206, 207) and the contact surface (200, 203, 205), the wall having a first upper axial end and a second lower axial end; an orientation of the contact surface extending from the first end being inclined so as to project radially inward towards the axis in the axially downward direction to define an inlet region; an axially lowermost part of the inlet region is terminated by a shoulder region, a contact surface at the shoulder region being inclined so as to project radially inward towards the axis from the contact surface of the inlet region in an axially downward direction; an angle of inclination ( a) of the contact surface of the inlet region relative to the axis is less than an angle of inclination (b) of the contact surface of the shoulder region relative to the axis; characterised in that: the crushing shell comprises a single shoulder region that terminates the inlet region, the contact surface from an axially lowermost part of the shoulder region to the second lower axial end defining a crushing face that extends immediately from the axially lowermost part of contact surface at the shoulder region, the crushing face orientated to be declined to project radially outward relative to the axis in a downward direction from the shoulder region to the second lower axial end. the crushing shell comprises a single shoulder region that terminates the inlet region, the contact surface from an axially lowermost part of the shoulder region to the second lower axial end defining a crushing face that extends immediately from the axially lowermost part of contact surface at the shoulder region, the crushing face orientated to be declined to project radially outward relative to the axis in a downward direction from the shoulder region to the second lower axial end.