Vegetable oil to oil a bike? Is vegetable oil as good as motor oil to oil a bike?
Vegetable oils tend to "polymerize", that is become sticky and solid.  Castor oil, for instance, is an excellent lubricant that was favored for racing autos and motorcycles for a long time.  The reason it never became popular for regular cars was that it also built up a lot of sticky, cruddy goo.   Racing engines are regularly torn down and rebuilt; no matter.
Not so your sedan.
The oils used in oil-based paints are usually vegetable-based as well; they tend to become quite solid after a while.

As I've noted before, lubes, especially chain lubes, seem to be a "thing" for serious cyclists.  Chain lube threads on dedicated bike forums tend to go on and on and on...
It's the engineering mentality at work.  "Maybe I can get 100 more miles out of my chain if I concoct my own special blend!"   Maybe...
Chain lubes are cheap.  They cost at most what, 10 bucks for a bottle sufficient for a year?
As well, chains are cheap.  Oh, you can spend a lot for super-deluxe items, but a good, well-made standard chain is under 20 bucks and will last most riders as long as they keep the bike if lubed and cleaned properly.

Related


"Best chain lubricant for road bikes?" Asks about the best lubricant out of conventional oils and lubricants
"Substitutes for chain lubricants" Asks about non-traditional substitutes for chain lubricant