Originally Posted by Djs
I had a similar issue with my 2013 40’ Infinity. My 5th Wheel was rated for 80 lb tires. I put on some that were 110 lb. This caused an extremely rough ride. It also did damage to the wood trim inside after a trip. I also found that my trailer shocks were shot. I replaced the tires with Goodyear Endurance rated at 80 lbs and replaced the shocks with Monroe’s and that solved the issue. It rides much smoother. Hope that gives you some ideas.
You don't have to run your tires at the maximum rated pressure, it depends on the weight they're carrying. I replaced the OEM Trailer King tires on our toy hauler (E rated, max 80psi, and poor quality) with Sailun S637's (G rated, max 110psi, very high quality tire). I initially ran them at 110, but as you both noted, the ride was brutal. I contacted the Sailun distributor and they provided a loading chart that indicated with the actual weight of my trailer, I could run them at lower pressures. I usually run them at 90-95psi so I still get the benefits of the Sailuns being a much better quality tire with higher load carrying capacity.
The max pressure noted on the side of the tire is the maximum pressure the tire can handle for the heaviest load it can carry. The tire pressure indicated on the placard on the side of your trailer is the manufacturers recommended minimum tire pressure for THAT trailer. Even if you replace the OEM tires with a higher load carrying capacity tire (e.g. switching from E rated to G rated), you can still run the trailer manufacturers recommended pressure (or a little higher), you don't have to max out the tires, although many on these groups will insist that you do.