Many years ago I was in school in Berkeley and I had to commute from downtown San Francisco. I bought an old Raliegh DL-1 3 speed (wish I still had it) which at the time, was the most un-cool bike there was, that I used to get from the Berkeley BART station to campus. It lived on the East Bay for two semesters with no theft attempts, locked only with a U-lock around the top tube.

Alas, I set it free when I left the Bay area, so I don't know its fate.