When I first joined TNBW in 2008, there was a limit of 5000 words you were permitted to post in one chapter/story with a single post. I don't know if that's still true or not. If it's still true, that alone would preclude you from posting a chapter longer than that. If it's not still true, I guess your best judgment will have to make the decision. Personally, if a chapter is much over 3000 words, I tend to move on to the next thing unless, as Marilyn said, it's a "can't put down read" or someone of whom I'm very fond (there are several of you out there - you know who you are!)
Also, I think genres such as "Adventure", "Action Thriller" and "Humor" need to move quickly to keep reader interest. A new chapter generally suggests movement in the story/action, which can be an enticement for the reader to continue reading. That could be movement in the scene or movement in a new direction.
Another thought (this applies to me and several folks I know) is that I have only so much time to read at one sitting and I don't like to quit reading in the middle of a chapter. So novels with very long chapters tend to make me look elsewhere for that very reason. I'm a huge Janet Evanovich fan and her chapters are generally 1200 - 1800 words. I have every book she's ever written and love the quick pace.
Just a few thoughts for what they might be worth. Good luck with your writing!
Alan