Floor bounce

[roaminaround]

First of all I know this topic has been discussed endlessly. Second, I have experience here. We formerly owned a 2006 Nash 26X front kitchen trailer. Great trailer, built like a tank. I installed the steady fast system and it was quite solid, minimal lateral movement and stabile. Last year we bought a 2019 Rockwood 2608BS. It’s an ultra light. Same length and weight as the Nash but with a bedroom slide as well. We instantly noticed a huge difference in bounce when set up. I assumed the electric stab jacks which aren’t supposed to be cranked down very hard instead of heavy duty scissor jacks were a part of the problem. We bought Xchocks for between the wheels. No difference. I assumed the ultra light frame was the problem. So I installed a set of scissor jacks fore and aft of the axles. Better but can still feel the 24 lb dog jump off the bed when I’m sitting in the slide. Also noticed the front left of the trailer sags down after a day of so by the front corner of the slide. So I installed a 5th scissor jack next to the stab jack on that corner. I still have an incredible amount of floor bounce. I’ve given up and assumed it’s the fault of the ultra light chassis and design. I don’t think the steadyfast system would help because it’s not lateral sway, it’s vertical bounce, unlike in our Nash. Any ideas before I give up?

[Lynnmor]

In my opinion, electric stab jacks are useless. I like watching those jacks skate around at RV shows. They belong on Craigslist and real jacks need to be in their place.
Yes, the frames flex plenty, but I think you can get reasonable function with a pair of scissors jacks at each end and a pair just in front of the axles. When adjusting, firm up the rear pair, somewhat less in the middle and less yet at the front. The idea is to keep some weight on the tongue jack. I go around two or three times using a hand crank for better feel. I use a drill to run the jacks to the ground and then stop.
Jacks can settle and the screw can back off gradually during use. These will help with that.

[colliehauler]

Don't know how the Rockwood ultralight floor is constructed but mine was 2 sheets of luan with foam inbetween. I didn't like the spongy floor and traded a new camper after one trip.

[theoldwizard1]

Standard floor is 3/4" plywood. They may have downsized to 5/8" or even 9/16" or space the cross bracing out further.

[roaminaround]

Kind of what I figured. At least the xtra scissor jacks allow me to fine tune lateral level like my old scissor jack system. I missed that with the electric stab jacks. I might get a little more stability when I replace the Castle Rock tires, although they are 8 ply load range D.

[kellem]

I'd give up, your dealing with a more flexible frame and likely floor joists.

When it was the whole family and a 60# dog, some nights I dreamt I was out to sea in chop.

Just the wife and I now so less noticable.