Bowlingboards.com is pretty active. Then you have the first church of Moe known as bowlingchat.net

Hey BR, are there any other (active) bowling forums out there?

Most active
http://www.ballreviews.com/index.php

active
http://www.bowlingcommunity.com/

was active but slowed way down, Mo hasn't been on for a year
http://forum.bowlingchat.net/

active
https://www.facebook.com/groups/BowlersUniting/

slightly active mainly because of a few long time users and noobs
http://www.bowlingboards.com/forum.php

was active but is barely active now
http://www.bowlingballexchange.com/

barely active
http://www.allbowling.com/

barely active
http://www.mrbowling300.net/

dead except for scoretracker
http://bowlingtracker.com/forums/

All the forums have slowed greatly, most of the users are the same ones on all the forums already, either using the same names or running under a different handle. With a few noobs joining for a little while and then disappearing.