Scrub Radius

[HenryJ]

Scrub radius is measured in inches. A line drawn between the two pivot points of the steering knuckle downward to the pavement surface. The distance from this line to the centerline of the tire is the scrub radius measurement.
The greater the number the more steering effort is increased.
Less rearspacing increases the scrub radius and increases steering effort.

[F9K9]

........The greater the number the more steering effort is increased.
Less rearspacing increases the scrub radius and increases steering effort.

What part of this is confusing me?

[HenryJ]

If you draw that line through the pivot points to the ground and measure to the tire centerline. That is the scrub radius.
If those points meet that is 0. That would offer the least resistance and stress on the steering.
Reduce rear spacing and you increase the scrub radius.
If you had 0" and add 1" spacers , reducing the rear spacing by 1" you have increased the scrub radius and the steering effort required to turn the wheel.

This is not all that critical in the street driving, but offroad where side loading and obstacles increase steering effort, the steps taken to reduce the scrub radius will pay off.

I realize that often times there is not a choice. If you have one, think about the effects of your choices. This is one.

Knowing that I have increased the scrub radius , I modified the steering pump to compensate.
In my case other changes influenced the friction created when turning. Larger tires, added weight, and I am sure there is more. It all affects the package.

[F9K9]

..........This is not all that critical in the street driving, but offroad where side loading and obstacles increase steering effort, the steps taken to reduce the scrub radius will pay off........

I certainly will not debate you on this but, appreciate the education.