Good tip about the triathlon. The downtown lakefront area will be jammed. Best bet would be to ride on Friday or Monday. Head north from downtown to the top of the path if you want a short leisurely ride (though be warned that the path is very crowded from downtown to about Belmont) or head south if you really want a workout.

The view going either direction is stunning. More than likely, you'll have a strong headwind or tailwind and that could help determine your course (do you want a tough outbound or return trip)?

And yes, if you want to take a pass on the tourist food and sights, ride up Milwaukee Ave. to Wicker Park for more interesting food, people, and shopping.

Feel free to pm with questions.