Abstract: Cage 4 for a ball bearing, comprising an annular heel 7 and a substantially axial portion 8 provided with claws 11 defining pockets 9 for balls and connected to the heel 7, the substantially axial portion 8 extending axially over a part of the pockets 9. The substantially axial portion 8 has an outside diameter smaller than the outside diameter of the heel 7, the outside diameter of the substantially axial portion being somewhere between the pitch circle diameter of the cage reduced by half the radial thickness of the heel and the pitch circle diameter of the cage increased by half the radial thickness of the heel.

Abstract: A wheel monitoring apparatus includes a measuring and evaluation unit designed to be fastened to the wheel in the region of at least one wheel nut or bolt of the wheel. The wheel monitoring apparatus includes at least one sensor for detecting a characteristic variable for a state of a wheel bearing and at least one sensor for detecting a tire pressure of a tire of the wheel.