How to rid and prevent rust without harming your R3

Yes.

Afriend of mine told me to use food oil and clean after application, and the rust does not comes back. He did it to his bike and really works.

In my case, I prefer to use sandpaper to remove the rust and than use nail polish after.
Cheers

Depending on where you live, rust can form just from the ambient moisture in the air over time. I was looking at the frame of the bike and the stock black paint looks to be pretty thin. I was actually thinking of putting more paint on there but to do it properly I'd have to really take a lot of the bike apart before I could get it done 'right'. I think I'll just worry about it when / if it happens.

spray the area with plastic dip will cover up the exposed area.