[Woodfin]

My experience with ladder bars is good. I have built several and tuned several others. With each case, ladder bars work well once the car is sorted out and usually only require a slight pre-load, sometimes none if used with an anti-roll setup.

I am pondering your question and visualizing the preload, and I do not see a way that a slight preload would cause any rolling resistance. A slight preload in the rear will not change the rear axle alignment.

In my experience, anything beyond a slight preload to make the car drive straight points to other problems.