My point was that the Sidewinder doesn't put any more stress on the fiver frame than normal, but yes it is at a different angle than normal. All pin box frame failures that I have seen reported deal with the 4 weld points to the front and rear crossmembers. The spacing front-to-rear is about 20 inches while side-to-side is only about 12 inches, so leverage on the welds would actually be less when the hitch is rotated 90 degrees. Static force (meaning the dead pin weight) acting on the frame is not the problem, dynamic forces encountered during towing are worse because they are in addition to the static force. The fiver probably spends in excess of 95% of it's towing life at angles of less than 15 degrees from the truck and certainly less than 1% at 90 degrees. Also, angles greater than 15 degrees are going to occur only at very low speeds (i.e. generally low dynamic forces). As an example, if I execute a 90 degree turn with the steering wheel at full cut, the maximum truck to fiver angle will only be 48 degrees and speed will be under 25 mph.
Having said all that, I agree that the real answer needs to come from Lippert. It would be good to know if they added any reinforcement to Keith's PP or even if they did any calculations for stress changes with the Sidewinder. At some point, I would like to add the Sidewinder to my Cruiser.
Texas Baptist Men-Retiree Builders member since '01
13 Silverado 3500HD D/A, 2wd CCSB srw, custom RKI bed
11 Cruiser CF32MK