The headset rotationally connects a fork pivoting tube (1) to a steering tube (2) of a cycle frame. It includes a lower roller bearing (3), an upper roller bearing (4), and an element (9, 10) for axially locking the lower and upper roller bearings (3, 4) against a lower or upper end of the steering tube (2). The mechanism for axial locking includes a first element of axial locking that consists of a circular groove (9) that is provided on the outside face of the pivoting tube (1) that works with a second element of axial locking that consists of a rib (10) with an essentially matching shape that is provided on an elastically deformable annular element (11) in a direction that is perpendicular to the axis (A-A) of the pivoting tube (1) and placed above the upper roller bearing (4) so as to exert a thrust against the latter.