At Home Depot they have these bike racks that are really just a horizontal 'V' that scews into a stud then the tops of the 'V' hold your top tube. The nice thing is they only cost about 4 bucks and come with mounting hardware (two screws).
Since it's an apartment you probably don't wanna ding up the walls to bad, but you're only talking a few screws here and a small tube of caulk will take care of that whenever you move out.