This way lies cycling madness

It happens every year. About 2,000 cyclists hunch over their handlebars, wait until midnight and then commandeer the streets of San Diego -- in costumes or pajamas. Wonder Woman, Madonna wannabes, the Loch Ness monster, the bride of Frankenstein and others take over the blacktop on a 20-mile loop around the city. (That’s a luna moth below, not an angel.) Last year one couple transformed their tandem bike into a twin bed, another pair cycled in beach chairs decorated with umbrella palms, and three men outlined their black outfits with neon lights. “It’s like ‘The Rocky Horror Picture Show,’ ” says Bob Remon, chairman of the way-after-hours Midnight Madness Fun Bicycle Ride, which started 31 years ago and resumes Saturday at midnight and raises money for kids’ athletic programs. The flat course, which Remon promises will have “hardly any wind and hardly any cars,” winds around Harbor and Shelter islands, snakes its way through Old Town and ends at Seaport Village. Top costume wins two tickets on Alaska Airlines; prizes also go to those who light themselves up -- with flashlights, glow sticks, whatever. Go to www.midnightmadness.active.com.