Want to view forum but restrict posts

[wilburforce]

I have managed to get most things working, it's a great plugin.

I have a page "Forum" a hard coded link to BBPress forums ( i will integrate it later).

I have two levels of membership:
0 - I assume is free
1 - Paid (although no one yet)

The page in wordpress is not restricted but when i do the following:

Enable API bridge - it forces all persons back to the join page (become a member)
Disable API Bridge - I can see it but user can then join through the BBPress interface, something I don't want

How do I allow all people to see my forum but when the want to post they are redirected to the s2 members login panel?

regards,

Paul