Critical Mass bike movement at 20 years

Bike riders gathered at Justin Herman Plaza in preparation for the 10th anniversary of Critical Mass. Police and organizers' estimates ranged from 3,000 to 5,000 riders for the 2002 event. Photo: Mike Kepka, SFC / SF

The bicycle party known as Critical Mass turns 20 on Friday. Hundreds, possibly thousands, of riders in all manner of dress and - if recent history holds true, no dress at all - will band together for a commemorative, congestion-causing cruise through downtown San Francisco.

The event comes at a time of enormous growth in the number of people who are engaging in what 20 years ago was still considered rebellious behavior - commuting by bicycle.

Chris Carlsson, the Critical Mass spokesman, said he expects 5,000 to 10,000 riders on Friday, more than 10 times the number of riders who routinely participate.

"It's going to be a gigantic mess, but it is going to be fun," Carlsson said.

Read more: http://www.sfgate.com/bayarea/article/Critical-Mass-bike-movement-at-20-years-3897679.php#ixzz27m7zrIXw