Adding a forum - any effect on SERPs?

I remember a while back I tried adding a forum to my site and my ranking fell a bit, so I got scared a removed the link to my forum. Now that my site is down in rank anyway, I thought that I may as well add the forum back to the site. I'm just wondering, could adding a forum cause your site to fall in rank? A new forum is afterall a PR0 and is kinda useless.

 

Adding a forum should not negatively effect your SERPS.

There is a potential theoretical PR loss to existing pages due to the effect of the links from you to the new pages, but I would put that in the "butterfly wings" category. The total negative effect on PR, if there is one at all, is immeasurably small.

Adding a forum will create a small increase in your PR as your number of total pages increases -- but this effect is also immeasurably small, if indeed it exists at all.

And then, there is the question of how much PR affects SERPS. I don't subscribe to the "PR is irrelevant" theory, but I also wouldn't worry about a slight dip in PR affecting my SERPS.

The benefits of an active forum far outweigh any potential drawbacks.

 

the only negative effect is, as Will Spencer said, that you will basically lose 1 link to your forum. but since you want to link back from the forum to your main site this will be very temporary until the forum is spidered. Also be sure to already have some content on the boards or they could be filtered for having duplicate (namely: "no") content