Here the rod consists of three sections: a long central one (with the rack) and two short ones on its sides, connected by pins. These short sections pivot to accommodate the rotation of the steering arms and reduce the central sections's forward-and-backward travel to zero. as Figure14-9 shows.
the three-piece tie rod is a reliable and popular solution, but its side sections must be shorter than the central one. The whole assembly is rather wide and thus not suited for narrow vehicles. We can solve this by building a very simple steering system in which the rack gear is replaced by a lever, as Figure 14-10 shows.
You now know three solutions to the problem of a tie rod's travel, and you have seen examples of simple steering systems built with a handful of common pieces. Now that your steering system is working, you may want to add features to it.