How much does a fly rod weight, aren’t they rather light?
For the beginner, understanding what a “weight” is when discussing fly equipment can be confusing. Start by assuming that we’re talking about size, and it’ll start to make sense. The most common question is “what size rod do I need”, and the most common response from the fly shop is “what do you want to fish for?” For now, let’s stick to single handed fly rods, not Spey.
History here, so jump ahead if you’re not interested. This will be short and sweet. The first casting of a fly for fish was documented in 1620, though Romans are thought to have fished with some kind of artificial. By the mid 1700’s fishermen, mostly in England, becan developing heavier lines of horse hair, braided and making it possible to “cast” hooks with dressings to catch fish. Silk was added to the horse hair and someone, who history has forgotten, began experimenting with “tapers”, adding or subtracting the number of strands to improve the way the line sent the lure onto the water. For two hundred years, horse hair and silk was the dominate material, though “certainly fishers were experimenting”. In 1935 Dupont introduced Nylon, a synthetic polymer that in many subsequent versions was used to create all the fly line advancements. Tapered lines were still the tedious work of braiding variations of the braided cord, but in the early 1940’s Leon P Martuch with Dow devised a coating so that the braided interior, still with us today, was of a uniform size and the coating contained the tapper. By 1959, a much needed clarification of fly line sizing was needed. Untilt then, tapers were labeled by agreed upon letters describing the size of the fly line: for example a double taper was called HGH (that was just one popular size) and a commonly used weight forward was GBF. The letter designated the diameter of the plastic coated line. The angler chose what line they would use.
In 1959, the American Fishing Tackle Manufacturers Association (AFTMA) created the standards we use today, weighing the first 30 feet of the line in grains or grams. The 2wt through 12 wt measures were now understandable but more importantly, rod manufacturers could now design fly rods and indicate what “weight” line would load the rod for proper casting.
Now, the weight designation does two things for anglers: indicates the line they need and the strength of the rod for handling the size of their quarry.The quality of the rods today also has had an impact on rod selection. Back in the early 1970’s, a 7 weight rod was considered a common trout tool, now the 5 weight is more universally identified as the trout rod, but i see more and more folks using 4 weights; graphite is being developed that is much more powerful that earlier versions, and considerably more powerful than fiberglass or bamboo, the line weight for “loading” glass and bamboo hasn’t changed, making a 4 weight bamboo rod awfully light for a 16 inch plus trout! Now we have multiple types of fly lines for a variety of conditions, not even discussing Spey or sinking lines, but the weight designation is still the best way to match to a rod. (I won’t get into over or under weighing lines on rods, there are a whole lot of good reasons to do that, but it’s mostly angler preference.)
Given all this, hard questions often take the form of trying to create greater flexibility. Different fishers pursue different fish in different conditions donchaknow. Streamer fishers tend to gravitate to six or even seven weight rods, but a five weight can work for streamers. Here in the Pacific NW the fun of Pink Salmon every other year, depending on the type of conditions you fish, a five weight can work, but plenty of folks move all the way to eight weights! Then there’ steelhead, salmon, bass, pike and panfish! Ideally, a dedicated fly angler is going to build a quiver of rods for all the types of water and fish he/she pursues. My admitted bias, a dry fly guy that loves mountain streams, limits my rods choices from a 2wt to a 6 weight. That's still a lot of fly rods! But at least the weight designation starts us on a sensible track!