The LEGO chain system has been present in the Technic
line since 1979, and despite its rarity, it’s unlikely to go out
of use. The chain consists of small, rigid links that can be
connected so that every link can be tilted relative to the next
one (see Figure 6-2). In this way, we can create a flexible
but rigid chain of any length, which can be wrapped around
gears. Figure 6-3 shows the size of the LEGO chain compared to a 1×2 brick. You may also recognize the chain link
as similar to the LEGO track link (see Figure 6-4), which is
used for tracked vehicles.