Here’s a handy way to tell how much a guy knows about bikes
It does not work for ladies. It does, however, work for computer knowledge as well as bike knowledge, which is interesting. I suspect the scientific explanation is that the more stuff you put in a guy’s head, the less room there is in there for hair, which gets pushed out of his follicles to a commensurate degree. But my beard is QUITE short so what do I know.