Critical Mass is a bicycling event typically held on the last Friday of every month in over 300 cities around the world. While the ride was originally founded in 1992 in San Francisco with the idea of drawing attention to how unfriendly the city was to cyclists, the leaderless structure of Critical Mass makes it impossible to assign it any one specific goal. In fact, the purpose of Critical Mass is not formalized beyond the direct action of meeting at a set location and time and traveling as a group through city or town streets on bikes. (Wikipedia)
The London Mass meets at 6.00pm on the last Friday of every month on the South Bank under Waterloo Bridge, by the National Film Theatre.
See you in the mass!!!!!!
Photo from landlelief