Just made a new hitch for my bike. the old one was worn out. Since its so bumpy and hilly here I tried to make it with some built in shock absorbtion. Seriously unloaded at over 10 mph the trailer can bounce five or six inches in the air. Cornering is interesting as it bounces sideways

The springs don't help with that, but they do dampen the rougher landings.
Since today I had a bit of a back of the axle weight issue the bigger spring is on the bottom.