We are on an extended trip, over 7000 miles so far. Had serious bucking issues with this new 26' Evergreen Sun Valley trailer first trip, so invested in an Anderson weight distributing hitch for anti-sway and anti-bounce before starting this trip. Never had any sway problems with the old "spring bar" EasyLift weight distributing hitch, but had severe bounce and bucking with this new trailer. We never had that with the old 23' rockwood trailer, same 2012 GMC truck and hitch. Both trailers have tandem axles.
Anyway, the Anderson hitch did help some, but it did not cure the problem. Still get a pronounced bounce on concrete roads when the joints are uneven. It's much worse with the trailer than without it on the same road, so the truck shocks seem okay. I'm thinking that this trailer has a long overhang behind the rear axle, and although it has 12% of the weight on the tongue, that overhang and some flex in the frame just give it enough leverage to cause the bounce.
I'm thinking of a suspension upgrade, adding shocks to the trailer. Has anyone done this, and what were the results? Thanks for your help.