Bearing unit having a double row of rolling bodies including: - a first ring, the first ring defining a first and a second continuous bearing raceway (4, 5) and the first ring including a first central axis, the first ring further comprising at least one mounting notch, - a second spherical ring, the second ring defining a third and a fourth continuous bearing raceway (6, 7), said second ring including a second central axis, said first and second rings (2,3) being radially spaced apart from one another by an inner space delimited on the one hand by the first and second bearing raceways (4, 5) and on the other hand by the third and fourth bearing raceways (6, 7), - a first row of rolling bodies and a second row of rolling bodies arranged in the inner space, the first row of rolling bodies being arranged between the first and third bearing raceways (4, 6) and the second row of rolling bodies being arranged between the second and fourth bearing raceways (5, 7), said first and second rows of rolling bodies (8, 9) coupling said first ring to said second ring for rotation therewith, - a bearing cage comprising an annular band, a first row of pockets and a second row of pockets, for receiving the rolling bodies (Cr), the first row of pockets being arranged on one side of the annular band in order to receive the rolling bodies of the first row of rolling bodies, the second row of pockets being arranged opposite the first row of pockets relative to the annular band in order to receive the rolling bodies (Cr) of the second row of rolling bodies, the cage being arranged between the first and the second ring (2, 3), characterised in that the first ring further includes: - a continuous seal bearing surface forming a surface of revolution about the first central axis, and adapted to receive a seal, - a continuous clearance surface forming a surface of revolution about the first central axis, adjacent to the seal bearing surface, - an axial retention surface adapted to limit an axial movement of the rolling bodies along the first central axis, - a mounting surface, having an overall axisymmetric shape about the first central axis, extending between the clearance surface and the axial retention surface, and adjacent to the clearance surface and to the axial retention surface, the mounting surface comprising the mounting notch for mounting the rolling bodies inside the inner space, whereby said notch does not project beyond the seal bearing surface. - a first ring, the first ring defining a first and a second continuous bearing raceway (4, 5) and the first ring including a first central axis, the first ring further comprising at least one mounting notch, - a second spherical ring, the second ring defining a third and a fourth continuous bearing raceway (6, 7), said second ring including a second central axis, said first and second rings (2,3) being radially spaced apart from one another by an inner space delimited on the one hand by the first and second bearing raceways (4, 5) and on the other hand by the third and fourth bearing raceways (6, 7), - a first row of rolling bodies and a second row of rolling bodies arranged in the inner space, the first row of rolling bodies being arranged between the first and third bearing raceways (4, 6) and the second row of rolling bodies being arranged between the second and fourth bearing raceways (5, 7), said first and second rows of rolling bodies (8, 9) coupling said first ring to said second ring for rotation therewith, - a bearing cage comprising an annular band, a first row of pockets and a second row of pockets, for receiving the rolling bodies (Cr), the first row of pockets being arranged on one side of the annular band in order to receive the rolling bodies of the first row of rolling bodies, the second row of pockets being arranged opposite the first row of pockets relative to the annular band in order to receive the rolling bodies (Cr) of the second row of rolling bodies, the cage being arranged between the first and the second ring (2, 3), - a continuous seal bearing surface forming a surface of revolution about the first central axis, and adapted to receive a seal, - a continuous clearance surface forming a surface of revolution about the first central axis, adjacent to the seal bearing surface, - an axial retention surface adapted to limit an axial movement of the rolling bodies along the first central axis, - a mounting surface, having an overall axisymmetric shape about the first central axis, extending between the clearance surface and the axial retention surface, and adjacent to the clearance surface and to the axial retention surface, the mounting surface comprising the mounting notch for mounting the rolling bodies inside the inner space, whereby said notch does not project beyond the seal bearing surface.