What are the best Bike Forums (mtn, touring, road)?

MTBR.com Pinkbike.com Roadbikereview.com are a few I would look into.

For light weight stuff check out light-bikes.com and weightweenies.starbike.com.

http://www.bikepacking.net/

For roadies http://www.bikeforums.net. It also has pretty good touring, winter, commuting, and other communities. It's probably the most active forum I've seen regardless of subject matter. Expertise is variable, though, and the roadie forum can be pretty brutal for a newbie.

MTBR endurance forum has some pretty experienced posters that will reply but the biggest concentration of people that bikepack off road has got to be http://www.bikepacking.net. It's awesome!

Ultralight biking:
http://sports.groups.yahoo.com/group/ultralightbiking/

Primarily colonized by those doing the Great Divide and some Iditarod racers.

mtbr.com of course

Didn't see crazyguyonbike.com for touring. Definitely a sensation.

Local bike groups are also one of the best sources of infromation since gear availability, road and trail conditions, weather and what not are highly regionalized.

When I'm touring I'll often find bicycle groups mailing lists for the areas or trails I'm planning on traveling though or on and ask them questions. They are invalueable and often as happy to provide info as I am to be able to ask it. Localied knowlege rules.

There are also a bunch of great mailing lists on various subjects: touring, bike company mailing lists, you name it. can't begin to give an overview but there is a whole lot of conversation out there. An order of magnitude more then the great niche that is this ultralight forum.

Oh… also, flickr.com. Not sure their forums are a good place for discussion but there are hundreds of bike related groups and they're very active, for photo sharing at least. Some discussion goes on in the comments on photos as well.

Cyclingforums.com and Cyclingnews.com, I really like the fitness Q and A on the later.

I only know mountain bikes.

If you want good tech info ridemonkey.
If you want to shoot the $hit with some cool people mtbr.
If you want to mingle with the pros and like the DH race scene vitalMTB.
If you want to listen to retarded 13 year olds talk about color coordinating parts pinkbike.