Fourteen years ago, Chris Carlsson and a few dozen of his cycling friends decided to take back the streets of San Francisco from cars in a spontaneous demonstration of the might of bikes. They enjoyed the ride so much that they decided to make it a monthly tradition. 162 months later, Critical Mass—as the motley collection of bike commuters, recreational cyclists, and the occasional hooligan is known—is a Bay Area landmark. Several hundred cyclists routinely participate in the controversial ride, which never has a set route or theme. The concept is so popular that similar rides have spread to at least 300 cities throughout the world by word of mouth. “With in three months of the first ride here, there was a ride in Poznan, Poland,” said Carlsson.