Have you ever wondered why designers show sketches of concept cars with massive deep dish wheels, but when those cars actually make it to production the wheels end up being fairly flat? Adrian Clarke talked about this recently from a designers point of view, but I’m going to tell you why this is true from an engineering point of view. In other words, I’m going to tell you why we just can’t have nice things!
Years ago, in days of old, cars came with wheels that had very deep dish styling. Life was good, cars looked cool and everyone was happy (okay, maybe that’s a stretch). Over the years, as technology marched on, deep dish wheels got shallower until finally, starting about 20 years ago, they became essentially flat on the outside. Why did this happen? Well, in a word, “steering” is what happened. The change from deep dish wheels to flat wheels can be traced back to improvements in the steering system — in particular, to the popularity and advantages of rack and pinion steering.