Critical Mass is often described as an 'unorganised coincidence'. It happens when a lot of cyclists happen to be in the same place at the same time and decide to cycle the same way together for a while.
WHAT'S THE PURPOSE?
"Everyday, all over the world, people are resisting the problem culture of the car by getting on their bikes and riding, instead of driving.
Critical Mass is a celebration of the alternatives to cars, pollution, accidents and the loss of public spaces and freedoms.
Not an organisation or group, but an idea or tactic, Critical Mass allows people to reclaim cities with their bikes, just by getting together and out-numbering the cars on the road"
WHAT HAPPENS ON A CRITICAL MASS?
Each one is different and they follow no set route, with the direction being spontaneously chosen as people cycle along. Anyone is free to join or leave the ride as it pedals along.
Tash't report of the Feb 2007 Critical Mass (with links to previous coverage): http://www.indymedia.org.uk/en/regions/nottinghamshire/2007/02/363222.html
http://criticalmass.wikia.com , including list of Critical Mass rides
http://www.urban75.com/Action/critical.html - Info & links
http://www.critical-mass.org/ (UK list not updated since the 1996s)
http://www.zap20.ukgateway.net/CMfaq.html - CM FAQ