Most of us use weight-forward fly lines, and when we introduce someone to fly fishing, we recommend a weight-forward fly line. Our sport must re-evaluate these two practices.
About 8 years ago (around 2014), Chris instructed me to buy a double-taper fly line to replace my weight-forward line. I was dumbfounded. Aren’t weight-forward lines better than double-taper lines?
But, when the Master of The Master makes a recommendation, I heed it. I bought a double-taper fly line immediately.
It turns out that a double-taper fly line was better than a weight-forward fly line when I worked on my casting. Chris may not always be right, but he’s never wrong. Since everyone should practice their fly casting, we all should own a double-taper fly line.
The Basics
Have you ever brought your line in, tilted your rod up and have the fly line fall through the guides pulling the fly up out of reach? Fly lines have mass.
Fly casting uses the mass and momentum of the line to deliver your weightless fly to the fish. Altering the distribution of mass along the fly line changes a line’s casting characteristics.
The relative mass of a particular section of a floating fly line is proportional to its diameter: the thicker the line, the more material coats the core, the heavier that part of the line. Consequently, a fly line’s taper details how mass is distributed along its length. Amongst casting lines, there are two main choices: weight-forward and double-taper.
In weight-forward designs, the part of the fly line that connects to the leader starts thin (tip), increases in diameter (front taper) to a section that is thick (belly), and then it decreases in diameter (rear taper) to a small diameter for the rest of the line (running line). The tip, front taper, belly and rear taper comprise the head of a weight-forward fly line.
The taper profile of a weight-forward line
In double-taper designs, the fly line has a tip followed by a front taper that leads to a belly with a constant diameter for almost the entire length of the line, and just before it ends, it has a taper and tip that mirrors the front section (so that it can be reversed). A double-taper line doesn’t have a section of thin, running line.
The taper profile of a double-taper fly line
Why Is Double-Taper Better Than Weight-Forward?
One of the best reasons for using a double-taper fly line is that it roll casts better than a weight-forward fly line.
When we learn how to fly cast and when we work on our fly casting, practice should always include roll casting at targets. If you didn’t know, the mechanics of a roll cast are the same as a front cast.
In a roll cast, the mass of the line in, and the energy imparted to the D-loop are used to pull the rest of the line out of the water and propel it forward.
At very short distances, a weight-forward fly line with a long belly, will cast like a double-taper fly line. As a caster learns to roll cast farther, however, the D-loop will contain decreasing mass as the belly is replaced by rear taper and eventually running line. Consequently, when the mass of the D-loop primarily consists of running line, roll casts will have a difficult time turning over the heavier mass of the head.
Sooner or later, every caster will need a double-taper fly line to practice roll casting.
What Are Other Advantages Of A Double-Taper Line?
Due to the mass in the belly of a double-taper fly line, it will also be easier to mend when fishing compared to a weight-forward fly line. Like for roll casts, this advantage increases with distance due to the distribution of mass along the fly line.
Another reason to use a double-taper fly line over a weight-forward line is that, once you wear out the double-taper fly line, you can turn it around and use the other end. Whereas a double-taper fly line has two lives, a weight-forward fly line only has one since it cannot be reversed. So, a double-taper fly line also provides an economical advantage.
Another reason to use a double-taper fly line over a weight-forward line is that the balance of the rod during the cast will remain more consistent with increasing distance. The reason for this consistency is that a double taper’s mass in the guides of the rod will be similar with increasing distance due to the consistency of the diameter of the double-taper’s belly. In contrast, the changing diameter of the weight-forward fly line’s rear taper causes the overall mass of the rod and line to change with distance.
The difference is subtle. But, when the I was preparing for the World Fly Casting Championships in 2022, I was changing the weight of the guides by tenths of a gram on my accuracy rod to get the action that I desired
Moreover, the lower mass of the running portion of the competition line made it susceptible to being blown by the wind, especially the line between guides – creating slack. At the same time, the wind and inertia would move the running line into the narrow spaces between the eyewire and the rod at the feet of the snake guides – creating friction. Double-taper lines have a similar issue, but not to the same extent due to the mass of the belly.
What Are The Advantages of A Weight-Forward Line?
There is a time and place for weight-forward fly lines. Afterall, weight-forward fly lines were designed to outperform double-taper lines in specific situations.
Double-taper fly lines have less flexibility in designs compared to weight-forward fly lines. One reason is that the mass of the first 30 feet of the line must be a certain amount to meet the criterion of a specific weight category. The other reason is that the head of a weight-forward line has more variables that can be altered than the front section of a double-taper line.
If a double-taper fly line and a weight-forward fly line had similar front tapers, their ability to turn over an air-resistant fly or to present a fly delicately would be similar. So, the advantages of a weight-forward design manifest in belly diameter, belly length and rear taper.
It’s important to understand that, in general, a weight-forward fly line will outperform a double-taper line when most, if not all, of the head is outside of the rod. This means that the caster must be able to carry a substantial amount of line to maximize the benefits of a weight-forward fly. In other words, the caster has to be good.
And when the caster is good, the general advantage of weight-forward lines is that they shoot line better. The lower mass of the running line allows the head to pull more line out for slightly more distance.
Epilogue
Unfortunately, we have been convinced that weight-forward fly lines are generally better than double-taper fly lines. When we work on our fly casting, however, double-taper fly lines are better than weight-forward fly lines.
A weight-forward fly line might be more appropriate than a double-taper in specific situations. But, fly lines don’t make you cast better or help you form tighter loops. Practice does. The right fly line simply makes a good cast stay on target better or go slightly farther – by distributing mass along the line in an optimal configuration.
If you want to make good casts and you want to get good at fly casting, you first need a double-taper fly line – not a weight-forward taper.