A method for lubricating a rolling element bearing, the method comprising a step of providing a bearing cage for retaining rolling elements when the bearing cage is in use, the bearing cage having at least one first ring structure to which at least one first cage bar is connected. The at least one first cage bar is constructed so that a diameter of the bearing cage is largest at one of a point or a region along the length of the at least one first cage bar so as to improve lubricant flow towards the rotational center of rolling elements when the bearing cage is in use.