Yeah I can imagine something as niche as cycling would be a constant struggle to grow. Especially when a lot of cycling posts are probably quite similar to photography ones and result in people posting in other communities more photography focused.

The OCD stuff is a good idea for giving communities a bit more interest through the curation side of things but it's only really a temporal solution. Get too big and your community is out to which the problem returns as curation dwindles. It's also quite a time and effort extensive concept for a lot of people with all the responsibilities of reading through posts, checking the accounts, nominating, etc.

Things like commentrewarder are a great idea since that doesn't entirely rely on a large group of people doing a ton of things all at once, and it definitely does improve some engagement. I don't think there's a specific solution to any of this though, I don't think it's necessarily a problem of specific groups or individuals not pulling their weight but more just the fact that Hive really is still in its infancy. If niche communities are struggling to chug along then it's usually just a case of low interest. And the low interest of course ripples into things like curation rewards which don't help things. But even if we had 1000 people posting daily in one community, it wouldn't mean much if none of them had the HP to upvote each other. Fatigue would still be inevitable.