Originally Posted by
KerryIrons
The only purpose of the retainer/cage is to make assembly easier at the factory and to prevent putting too many bearings in the HS.
FWIW, a case can be made for caged bearings beyond assembly convenience. How relevant it might be in bicycle applications has not been established:
https://www.machinedesign.com/mechan...-reduced-noise
I use caged bearings when the cage holds the full complement of balls that race can hold; e.g. as in high-end headsets from Campagnolo, Shimano, etc. If the cage holds fewer balls than a full complement, by all means replace it with loose balls, especially in the lower race.
