The first time I set out along the Wiggle, I carried a wrinkled receipt with the street names scrawled in blue ink on the back: Fell, Scott, Haight, Pierce, Waller, Steiner, Duboce. Through the first few turns, I checked and rechecked my cheat-sheet, but by mid-Wiggle, I realized that no cheat-sheet was necessary. The flattest route was obvious — in fact, it was marked on the pavement with faded arrows — and more important, the flow of bikers was thickening.
This, even more than its flatness, is the power of the Wiggle. It’s a funnel. I rode my bike to work most mornings after that, and I always looked forward to the effect. I’d start out alone, pushing up that shallow grade. Next I’d curl through the corner of Golden Gate Park and into the long green strip of the Panhandle, where I’d pick up a few fellow travelers. And then, the thickening: I would zigzag through the Wiggle, gaining new companions block by block, and emerge onto Market Street in possession of a posse, an impromptu bicycle gang, a protective cohort.