donbrew

Are you considering that they are ball bearings?

vinmansbrew

Sure am, and I still never seen 1 do that.

donbrew

I have. Even with old fashioned wheel bearings. They can also lend to cupping.

Geometry and physics says a wheel on an axle will tend to camber upon application of downward force. If the bearing of the wheel is loose it will succumb to that tendency.