Note: Selecting Rod Action
This is the term used to describe the flex of the rod, or the relative resistance to bending as one moves down the length of the rod. These actions are referred to as fast and slow, and various moderations and combinations of the two depend greatly on the manufacture and design of the rod tapers.
A fast action rod has the tendency to resist bending in the lower part more so than a slow action rod. A fast action rod will normally be more suited to the experienced fly fisherman, as it requires a more precise timing and control of the back-cast. It has the characteristics necessary to generate higher line speeds, and therefore greater travel distances. It is the flex to use when casting into a stiff breeze or where distance is required.
A slow action rod would tend to be more “whippy” than a fast action rod.