Originally Posted by
Andrew R Stewart
Most bearings fit the hub with a slight press fit. This can compress the outer race a bit. .....
The compression of the outer race, and expansion of the inner race is calculated and engineered into the bearing to provide the design preload when installed. If you read the tech data on commercial bearings they described the design class of fit and tolerance. In any case, the dimensional change is pretty small and not likely to be noticeable as much as the effects of excess thrust loading or damage to a seal.
Commercial bearings that run hot, such as on lathes or jet engines even have the effects of thermal dimensional change engineered in. Most high speed machinery has specs. for how to properly adjust a baring cold, so it'll come to spec when hot. Precision machines lathes and millings need to be warmed up before cutting is done because cold bearings are loose and the spindle will vibrate causing off spec work or chatter marks if cutting is started too soon.
This engineered precision is why I prefer to work with angular contact bearings, where errors can be adjusted out.