I see what your saying.
Can you recommend a way to test it?
Should I just jack a corner up?
And when do the bumpstops come into play?
If you look at your axle tube, below the stop sticking down from the frame rail, you'll see your remaining up travel (The rubber can crush a bit on impact/pressure, so there might be another inch or so, etc...). IE: The tube comes up until it hits/crushes that stop.
If you take a string, and run it from your pack's FRONT mount, to the rear lower shackle mount (to the pack)....you get your baseline.
Then, measure the distance down from that string to the top of the pack at (Under) the axle tube. That's how far up the pack can unbow w/o getting too excited.
So, you look at how far up it can go to hit the stop, and, how far is too fat to unbow...if the stop is still not hit, you have uptravel left, which is good for articulation.
If hitting the stop would mean the pack passed your baseline, IE: Unbowed and now reverse arching, the stop is allowing articulation, but not preventing reverse arching.
If the axle stops rising because the load leaf is acting as a defacto stop, that's bad for articulation.
If the load leaf is allowing the pack to pass the unbowing limit you'd want, then, you are still able to reverse arch with the OL in.
When that happens, the front leaf eyes get pretty stressed, and at the ends of the OL, the remaining leaf in support can get bent at that fulcrum point....and fatigue snaps start after a while in some cases. (They can happen even with none of this occurring too, but a reverse arch accelerates the process)
So, if the shackle swings out (To the rear), enough, it can relieve that, and allow the uptravel w/o the arch getting too bad.
If the shackle swings IN, you can find that off road at least, a stuffed tire can pop the pack into a reverse arch that binds hard against the frame rail, and which is a royal PITA to undo.
That's something you want to avoid. :sure:
So, yeah, back a rear tire, on each side, onto a decent ramp, load weights, etc, to get the compression hard to the stop....and note what you see.
I recommend undoing the lower shock mounts first too, as its a good time to see the compressed and extended lengths that work too.