Brass bearings and bicycles

[fshbydesign.com]

It's actually oil. Oil soaked or oil impregnated bronze is used for bushings and bearings. In the end of a flywheel they use an oil soaked bronze pilot bushing that carries the end of the input shaft on a manual transmission.

Oilite powdered bronze is soft, but works very well as a bearing surface.

 

[Archie Sturmer]

I have found that some acidic solvents (used), for removing calcium lime rust (CLR), tend to deposit a pinkish copper film layer on steel parts; the acid is not exposing any existing copper alloy content.

And then there is the red and yellow brasses and bronzes, and the leaded and unleaded.

A benefit of brass ball bearings on a show bike might be that they would not be a source of rust. I avoid bronze hardware on bicycles, including axle or stem washers, but use them (painted or not), sometimes even with nylon washers, for fender mounting hardware.