BicycleTutor.com - http://bicycletutor.com/
Offers bicycle maintenance and repair instructions by Alex Ramon.
BikeCafe - http://www.bikecafe.net/
Worldwide bicycle portal, providing a directory, articles and news.
BikeLane.com - http://www.bikelane.com/
Offers a comprehensive collection of useful bicycle sites and resources.
Bloom Bike Shop - http://bloombikeshop.com/
Find information about bicycle maintenance and repair, setting up a home repair shop, and finding a good local bike shop, or LBS.
Cycling.com - http://www.cycling.com/
An online portal for cycling passionates offering news, product reviews and information on bicycle tours. Includes forums, photos. videos and articles.
CyclingForum.com - http://www.cyclingforum.com/
Attracts some of the most passionate, talented and experienced bicyclists/cyclists from throughout the world.
Pedaling.com - http://www.pedaling.com/
Aims to bring great cycling routes to recreational and avid cyclists.
Ride the City - http://www.ridethecity.com/
Features an application that helps bicyclists find safer routes around cities.
SocalTrailRiders Forum - http://socaltrailriders.org/forum/
The premier mountain biking community in Southern California.
USA Cycling - http://www.usacycling.org/
Official site of the cycling governing body in the United States featuring information on the athlete programs offered and events. Also includes resources, news, hall of fame and membership details.