UBI charges $750 for the "Introduction to Cylcling" class. I would do it for that.

As above, showing someone how to do something more complicated than changing a tube is a pain(And even showing how to do this is usually pointless, the person, who has admitted they do not know how to do it, never even buys the most basic of tools needed to perform this simple repair. In one ear , out the other).

It takes longer, your train of thought gets interupted answering questions, your boss gets annoyed because your productivity goes down, you make no money from it.