in order to figure out what this article is saying, I have to learn a lot of terms, and I don't think it's going to be that astonishing or "aha!" so it doesn't seem worth it. The positive scrub ratio measured along the kingpin axis from the kingpin center... if only I knew what a deep dish wheel was as opposed to a flat wheel...
you need to afix another point in your picture. Imagine a basic wheel mounted on the end of a solid axle. Now imagine that you made the axle shorter and replaced the wheel hub with a cone ("deep-dish") that has the tire mounted on the rim at the wide end of the cone. Did you change anything other than angular momentum (I guess I should say polar moment)?
if you want to say, "you can't use a cone like that because there needs to be a hinge on the axle at this point for the wheel to steer-turn" then we've arrived at the reason for the limit on deep dishes? or if it's some other reason, it still doesn't seem that hard to describe.
what I'm really saying is, the geometric concepts could be taught more simply without the all terminology. My older brother raced cars that he fixed and modified himself, so I grew up basically in a mechanic's shop. That was a long time ago so it's fine if terminology and concepts have changed, but I have a big head start over the average person and I found the article annoyingly incomprehensible
