In order to access the user forum for the CrossClave application you will first have to create a CrossClave account by setting one up free via crossclave.spideroak.com (if you have not already done so). After you have created your account, navigate to spideroak.chat. This is the forum's address.
You can now login, select the 'Log in' button in the top right corner. The page may load you into a login screen if it does not automatically detect your credentials from crosclave.spideroak.com. Enter your CrossClave web credentials if you are not detected and select the 'Log in' button. If the login was successful you will be taken back to the Forum page, logged in at spideroak.chat.
If this is your first time at spideroak.chat, the site will need to send you a confirmation e-mail after you enter your login credentials. Check your e-mail and select the link therein to confirm your identity. The page will ask you to confirm your activation, do so and the page will reload to the general forum view.
If this is your first time here, the page will offer to guide you through how to use it with a short tutorial.