Abstract: A roller bearing unit comprising an inner race element having a homokinetic coupling at one end and a coaxial extension forming a gudgeon at the other end whereby two rotating tracks for two rows of rolling elements are provided on the outer surface of the inner race, an outer race having a conical shape surrounding the rolling elements and being integral with an attachment flange, whereby the rotating tracks for the rolling elements have different diameters, the larger diameter track being at the homokinetic coupling end and being closest to the attachment flange, the larger diameter track being formed directly on the inner race.