A three mile stretch each way, the boardwalk is a great place to rent a bike and enjoy the gorgeous San Diego weather. Or check out the neighborhood and just bike around Pacific Beach. There are lots of shops and restaurants found on Garnet Ave. and most bike rentals companies include a bike lock with your rental.
There are several bike rental places found in Pacific Beach. We really like riding the cruisers. After you hand in your bike satisfy your hunger at Oscars Mexican Seafood http://www.oscarsmexicanseafood.com/ for a taste of local flavor.
Tip: If you choose to bike the boardwalk, it can be crowded on the weekends, so either start earlier in the day or go on a weekday.