A support ring assembly for a railway axle having a support ring configured to be inserted between a rolling bearing and a collar of the railway axle, the support ring having an annular seat, a surface of a radially inner side wall fitted with a radial clearance over the collar and an end wall that abuts against the collar, an annular insert fitted into the seat by means of an annular shield and having an elastomeric annular element having at least two annular protuberances that engage with the collar, the annular element configured to engage with the collar so as to occupy the radial clearance.