Here’s some cycling events going on this summer for all kinds of riders. More to be added, but feel free to add more via comments…
–London Beastway: 11 mountain bike races on Hog Hill from 19th May (today, sorry) to July 28th.
–The Pleasant Revolution World Bicycle Music Festival Tour: in London June 5th-6th.
–World Naked Bike Ride, London: Saturday, 12 June. Go naked and dress up that bike!
–Dunwich Dynamo: 120 mile free-and-easy cycle from Hackney to the Suffolk Sea at Dunwich over the 24/25th July weekend.
–Ecotopia Biketour – In its fourth year, this time cycling From N. England to Germany totaling 1600 km! Join or host the cyclists.
–Bike Pride 2010, Turin (Italy): 6 June, to promote cycling and the environment
56abikespace's Blog 
Hey this is cool!
One correction though: The Ecotopia Biketour is rolling this summer for the 20th time! (wow!)
Everyone’s welcome to cycle with us if you’re alternative-minded 😀
Other cycling event : the first CRITICAL MASS in PARIS, from 1st to 5th July !!! Come and discover Paris with other eyes! http://velorutionuniverselle.org/ see you there !