I have an Extreme Sports website www.magxzine.com that has been up for a few months.

I have done almost no promotion on the site but I am begining to attract a few visitors ~150 uniques per day. Average pages are about 2.5 per visitor.

I am considering adding a forum to the site to keep visitors coming back on a regular basis but do not really have time to get involved heavily with posting and maintaing a forum.

Is this something I should persue now or should I wait for more traffic before attempting?

but do not really have time to get involved heavily with posting and maintaing a forum.

This is the main problem: you need to spend a LOT of time in your forums in order to make them survive at first and then grow. If you have the time to do it, then it's a good idea, but otherwise you'd just prepare yourself for a bit fiasco. I know in all webmaster articles (even mine :D) you're told to create a community to have returning visitors. But you need to really know if you are willing to put all the time and work it needs ..

I have checked your site, its look good, I hope you should add forum on it, start with good posts, let few people close to you to contribute to your forum.