I had to re-read that a few times to see get it, and I think I almost do. So let's see if I have it right.
I think we all know, from the previous post, how compression dial works. I'll take an example, made up shock with adjustments from 1-4, like KW's. A lower number, (like 1) means that its super difficult to push the rod into the cylinder. a high number, (like 14), means you can push the rod into the cylinder very easily.
Now, for the rebound dial, a lower number, like 1, would mean that, for the same shock, starting from a fully compressed state, the rod will shoot out super fast, launching a Lego to the top of Mt. Everest, and a high number, like 14, would be like an elevator submerged in molasses, taking 30 minutes to go from fully compressed to full extension. Not that extreme, but did I get this right so far?
So, putting this together, Let's take a shock which has a rebound setting of say, 14, (which is super slow to extend) and is mounted to the rear wheel, and then have the car drive over a 2x4 lying flat on the ground. What will then happen is this.......
Right when the car hits the 2x4. the shock is going to compress, pushing the wheel up into the wheel well. Then, after the car drives past the 2x4, if the rebound number setting is not low enough (meaning, the shock extends way to slowly), then the wheel is still stuck up in the wheel well, and not descending to the ground fast enough. Since the wheel has not descended, that part of the car falls onto the ground instead, jarring the occupants..
Is that sort of the gist of it?