Critical Mass is a monthly event held in many of the major cities of the world. It's a chance for bicycle riders, skaters, and other non-motorised road users to come together and spend the evening going for a ride. There is no leader, and there is no route - the mass just flows through the streets, going where it wants.
It all started when a group of cyclists in San Francisco got together back in 1992 to go for a ride in a group big enough that they wouldn't get bullied by the motorised traffic. It soon caught on, and sixteen years later it has spread across America and the world. The UK has several masses: London is by far the biggest, with up to two thousand riders at a time, but other cities' rides are growing fast.
Critical Mass is always good fun. The people are friendly, the atmosphere is lighthearted, and there is an amazing freedom in approaching the junction that you dread and suddenly realising that today there's no threat at all. You get to see things you pass every day and never get the chance to appreciate; you get to breathe air that isn't half exhaust gas; you get to appreciate what a city might sound like without the constant roar of engines. It's undoubtedly the best way to spend a friday evening. You don't have to worry about keeping up or fitting in, either - although there is the occasional lycra-clad roadie (and they're welcome!), the majority of riders are ordinary utility cyclists in ordinary clothes. The emphasis is on sticking together, too, so there is no danger of not being fast enough.
As well as being fun, Critical Mass is important. If you've ever commuted on a bicycle or skates you'll know that many road users can be agressive and dangerous. As vulnerable road users we bear the brunt of other peoples' mistakes, and as a minority we sometimes inspire irrational hatred and anger. Critical Mass gives you the ability to tip the power balance the other way for an evening. It demonstrates to other road users that we are traffic, and forces them to give cyclists the respect they normally reserve for cars alone. It demonstrates to pedestrians what their city might be like without motorised traffic. It's an impressive spectacle that persuades others to get their bikes out of dusty retirement in the shed and use their cars less often. And it's a simple statement that we can't always be ignored or bullied out the way.
This is a short post, and I can't really do my subject justice. If you'd like to know more, there's loads of information on the internet. The Wikipedia article on the event is detailed and interesting. If you've got time, watch We Are Traffic, a fantastic fifty-minute documentary which explores its history, purpose, and effect.
Remember, the more riders there are, the more fun the ride and the louder our voice will be, so come along and join in. I hope to see you there!