A rolling bearing assembly has inner and outer members, rotatable with respect to one another, and defining a pair of races therebetween. Each of these members has a flange-shaped portion for mounting the respective member. A separate row of rolling bearings is provided in each of the races. The outer member is formed with separable ring-shaped portions defining the running surfaces of the two races, the separable portions forming an inwardly directed annular ridge under ajoining faces, so that the rolling elements abut the sides of the ridge. One of the rows of rolling bearings has twice as many rolling elements as the other row.