The Earth Day (or "Earth Week" in this case) ride is usually Calgary's biggest Critical Mass ride of the year.

Participants are encouraged (but not required) to dress up in costumes, decorate your bikes and bring noise-makers & musical instruments you can play while riding. Bike-mountable flags, signs and banners are also encouraged.

The Arusha Centre is hosting a social event after the ride, along with a screening of "Still We Ride" - a documentary about Critical Mass.

On the last Friday of every month, cyclists around the world gather to ride the streets together to assert the rights of non-automotive traffic to use the streets.

For more information, see http://criticalmass.m...