Abstract: A bearing unit provided with a radially outer ring, a radially inner ring, a plurality of rolling bodies interposed between the radially outer ring and the radially inner ring, and a retention device for keeping in position the plurality of rolling bodies, having a circular base rib, a plurality of fingers circumferentially spaced and defining a plurality of cavities for holding respective rolling bodies of the plurality of rolling bodies which are in contact with the retention device by means of a contact surface, and a plurality of discontinuity elements which reduce the extent of the area of contact with the rolling bodies.