Yes, any of the cheap athletic shirts such as the C9 you mentioned or the Starter shirts at Wal-Mart work great as a cycling shirt as long as you don't need the pockets. One thing to note is that they have the fit of a T-shirt which is a bit different, cycling shirts are made to fit properly when your body is leaning forward and is a bit longer in the back to keep your lower back from showing when leaning forward.