Hard to say if it's the ads, it shouldn't be as the ads are supposed to load after the page loads. Even before the ads I have noticed page load speed times when it takes a few extra seconds but it seemed to come and go for me, I eventually chalked it up to the hosting server being a bit slower than typical since it seemed to come and go randomly.
If anyone wants to try they can use the developer tools in a browser to get an idea of what's taking a long time. Every browser is a bit different but in Chrome it would be "More Tools -> Developer Tools" and then there's a Network tab. Once that is visible you can refresh the page and it'll give a giant list of everything that's loading and how long it took. You end up with something like this:
Would be interested to see what that looks like on ones that are having page load slowness. Probably only a desktop browser feature.
If it's the forum.calgarypuck.com one that's taking that long that means its the server itself that's talking that long to create the page to send to you.