Discussion, not arguing...
The bar ends have a smaller contact area, so the PSI will be higher
The head to bar socket has a lever arm, the 'L' bracket contact has none
As the trailer swings...the bar length is shortened. How much taper does the
bar have? If significant, higher spring rates the far off centerline the trailer goes
That is my gut feel and why still think the friction is more out there at the 'L'
bracket, but, there is friction at both bar ends and at the head.
Question: are the bars parallel to the tongue, or are they at an angle that comes
with a head tilt?
If yes, then this heaps on top of the above bar taper