Critical Mass Bikers Rule the Roads WSJ's Phred Dvorak reports from a Critical Mass event in San Francisco, a monthly bike ride that draws hundreds of cyclists. She talks with bikers as well as disgruntled drivers. (Aug. 20) Critical Mass Bikers Rule the Roads WSJ's Phred Dvorak reports from a Critical Mass event in San Francisco, a monthly bike ride that draws hundreds of cyclists. She talks with bikers as well as disgruntled drivers. (Aug. 20) bike cycle cyclist critical mass san francisco