This is sort of a hi-jack. Does the Flippac's torsion bar work on the same principle as the Wildernest? The wildernest literature states that it can support the weight of two adults without the poles. In fact, the poles are only there to add support during high winds.
I bring this up to illustrate how crucial the hinge/torsion mechanism is in the Wildernest, in case its the same in a flippac.
The Wildernest uses a spring hinge anchored to the vertical walls of the structure along with a cable system that goes from the vertical wall on the vehicle side of the shell to the apex of the center pole down to the outside end of the open lid. This system put enormous stress on the spring anchor points which ends up cracking the fiberglass vertical wall and splitting the embedded wood.
The Earthroamer JK uses a beefed up center pole, winch cable, and winch to open and close the lid. The nature of the design causes the lid to pull off center.
The FlipPac uses a torsion rod that is under zero torsion when the lid is in the vertical position. The torsion bar provides support to the open lid, along with the legs to the vehicle when open. Failure of the torsion bar is the primary drawback with this system. I'd guess there is a 15% failure rate if you looked at all the FlipPacs made since 1979.
Having gone through the design and manufacture of torsion bars for the JK Habitat I'd say the following. The torsion bar system is very reliable
if the bar is well designed, and made by a forge that has extensive experience making torsion bars. I do not know who makes the torsion bars for FRP and they don't seem keen to tell me. The FlipPac torsion bar failures I know of seem to be random rather than related to bad production batches, and don't seem to follow any pattern when it comes to the usage of the FlipPac, i.e. on road vs. off road.
As you can see none of these systems are perfect. The Wildernest and Earthroamer systems produce the same results over time so they are consistent with their issues. The FlipPac has random issues.
The good news is that FRP just got torsion bars in stock, so if you need one call them and place your order.