hone eagle wrote:
OK here is a long video by a hitch designer ,its long so FF to the 5;30 mark where he discussed air bags.
"they should be inflated to 50% of max " 
I have talked to him in person and he explains it better ,but too much pressure (and the max on the typical bag is 100psi) they are just a vibration damper ,for max perfmorance or 'squish' they should be specced at 1/2 volume or pressure
henry s and the ET hitch
I haven't watched that video but couldn't agree more, I never run my Trailair pinbox at the recommended air pressure. Or at least where they they have that black line adjustment marker.
I always run it much less and have found that my small (26') 5th wheel rides 100x better with less air in the inflation bag. Of course you guys running larger rigs may find that your results may vary.
My point is don't be afraid to play around with the pressure, one psi doesn't fit all.
Ron W.