A ball bearing for permitting longitudinal movements with respect to a shaft includes a cage provided with at least two longitudinally extending guide tracks having opposite ends that are connected by semicircular turn around tracks. A plurality of balls are positioned in the guide tracks, with balls positioned in one of the guide tracks forming load-bearing balls and balls positioned in another one of the guide tracks forming non-load-bearing balls. The longitudinally extending guide track for the load-bearing balls is provided with a slit that is open radially inwardly for passage of the balls in a direction radially inwardly towards the shaft. The longitudinally extending guide track for the non-load-bearing balls has an interior wall which, in cross-section, possesses at least two substantially diametrically opposed first sections having a circular contour and at least two substantially diametrically opposed second sections laterally offset from the first sections and having a base that is set back from the circular contour.