Spinning turmoil in S.F. - Motorists fume as hordes of bicyclists jam city streets in free-form rides that draw kudos and condemnation.
SAN FRANCISCO -- The sea of bicyclists surges up this city's Financial District, a boisterous mass of freewheeling humanity, 1,500 riders strong. Pedaling six abreast, they send pedestrians scurrying as rush-hour traffic hits the brakes.
A cable car slows, engulfed by riders who whoop and holler or chat on cellphones. A traffic light goes red, green and red again. Still the bikes keep coming.
As a bystander high-fives passing cyclists, one car in a line of idling motorists lets loose with a long, blaring, impatient horn blast. A tourist snaps a photograph and asks: "Are you protesting global warming?"
"No," one rider shouts back, "we're taking over the streets!"
Some call it a bicycle insurrection against the thoughtless motorists who hog city streets. Others say it's about nothing more than fun.
On the last Friday of each month, the cyclists of Critical Mass embark on an unrehearsed crosstown jaunt that -- for a few hours -- transforms the urban landscape.
When Critical Mass hits the streets, bikes rule. Sometimes with sharp elbows, riders brush aside the cars, trucks and buses that stand in their way. And often, tempers flare.
Bicyclists and drivers get into fights, cyclists slam their locks onto car hoods and police make arrests amid pointed turf battles. A decade ago, former Mayor Willie Brown declared war on the marauding cyclists, whose exploits he dismissed as "the ultimate arrogance."
But Critical Mass stubbornly survived, and even flourished.
Started here in 1992 by a handful of idealists, the free-form events have spread to every continent but Antarctica and to 300 cities worldwide, including Los Angeles.
Next month, the ride celebrates its 15th year. But it still has no leaders, no route plans, no spokespeople.
"How the rides unfold is always a mystery," said Chris Carlsson, a ride co-founder and editor of a book, "Critical Mass: Bicycling's Defiant Celebration."
"They're predictable yet unknowable. People keep coming back to see what will happen."
Critical Mass riders, who refer to themselves as "massers," insist that they're not tying up traffic -- they are the traffic, albeit a two-wheeled variety. Their aim is to force cars to share the road and leave enough room for bike lanes, so cyclists won't have to fear injury and death.
