Lighter than Plastics...
Especially in automotive engineering carbon (CFK) is the benchmark in terms of light weight . Franke light weight bearings with housings parts of carbon are the best example. The advantage of carbon lies in the variable arrangement of the fiber structures. Depending on the subsequent load on the bearing forces in axial or radial direction can be dealt with this way.
Franke wire race bearings of carbon have the same load capacity as comparable bearings made of Aluminum, with the difference that they are lighter by about 1/3.