Originally Posted by oldbobcat

As the video shows quite clearly, the chain is not touching the neighboring cog. But the inner-plate links are not fully engaging until chain tension pulls them down. Notice how the the trailing (left) side outer plates "hangs" momentarily before dropping down. Ordinarily, that would indicate the roller on a worn chain catching on the leading edge of the tooth of a fresh cog. But, as the OP indicated, the chain is fresh, and, as I've indicated, it's only happening on every other link. Watch it carefully. Every trailing (left) end of an outer link hangs momentarily. Then it drops, like, clunk! That's because the link it's attached to, the next link in line, an inner plate link, is hanging on something every single time. And if it's every tooth, it can only be the width of the cog.

By they way, trying the wheel on a different bike would only add more unknown variables into the test. I don't understand this resistance to trying an 8-speed chain. They're cheap and plentiful.