Bullitt on bikes

Blink and you'll miss the racers at this month's Grand Prix

Tim Larkin, a veteran pro cyclist with the Kodak Gallery/Sierra Nevada team, calls the San Francisco Grand Prix "the hardest single day of racing all season." For Larkin and a hundred or so other elite cyclists, the one-day race, held each September, is a gut-wrenching, gear-crunching, lung-busting course over hills so steep they have stairs carved into the sidewalks.

For spectators, it's a chance to watch some of the world's best athletes streaking 108.1 miles (51.6 miles for the female racers) through North Beach, the Marina, and Pacific Heights. "With half a million people watching, it shows how far cycling has come," Larkin says. Many of the racers are international team riders, including some from Tour de France teams (you probably won't see Lance Armstrong―he retired from pro racing after winning his seventh straight Tour).

Best spots to take in this year's action: the Ferry Building (where the race starts and ends) and the brutally steep ascents of Fillmore and Taylor Streets, which the racers tackle 9 and 14 times, respectively. And all you have to do is watch!

INFO: San Francisco Grand Prix starts at the Ferry Building (Sep 4, 7 a.m. for the women's race, 10 a.m. for the men's; Embarcadero at Market St.; www.procyclingtour.com); the race lasts about four and a half hours.