I keep thinking that I'm headed out of here soon, so I'm not looking for my dream bike. I want something that will give me the greatest efficiency for longer distances on the road. I'm looking at 25 mi (50 rt) rides for swim laps).

A bike for this season, maybe next. I have to be aware of the enticement factor as well because I anticipate the bike to be locked in public for significant periods(6-8 hrs on campus). Ultimately, I am serious about training for an Ironman. The budget has identified a few bikes; should I opt for a lower ended newer bike like a Denali, an older Schwinn, or a Trek 700 hybrid for durability? These are what I have access to at this point.

Thanks for opinions.