For some geeky discussions on tailing loops go here:
As an attachment to the previous articles on tailing loops (here and here) now an exercise on diagnosing a common casting fault. You are a casting instructor and your student is getting a recurrent tailing tendency. I shot this clip yesterday, playing as student and instructor at the same time. After dozens of plays I still can’t say what the origin of the problem is, even seeing when it is produced (watching carefully you can see the slight rise of the rod tip and the subsequent wave in the line).
What I know is that I was playing with the haul, trying to release the line just at loop formation (wherever that is). That could have resulted in a premature end of the acceleration of the hauling hand and the immediate tip rise. But, honestly, I don’t know and find incredibly difficult to diagnose and cure this kind of things.
Tailing loops. So frequent and still so puzzling.
As I wrote on the first post in this series we already have a pretty good idea of how tails are formed; getting rid of them is another matter entirely. I truly admire the insights of instructors from yesterday: reaching the conclusion that tailing loops come from a concave tip path of the rod tip wouldn’t come easily, specially if we take into account that there wasn’t high speed video available at the time. Today’s technology effortlessly shows that, in fact, it is a dip/rise of the rod tip what creates the dreaded tail. And this evidence renews my admiration for the amazing observation skills of those pioneers of casting studies, for although that dip/rise is somewhat a “concave path of the rod tip” it has nothing to do with those big bowl shaped tip paths so many drawings depict. For years those bowl shaped explanations were to me as perplexing as the tailing loops themselves: however much I looked whenever I saw a tail in someone’s casting I couldn’t see that big concave path everybody was writing about. Not even on the casting videos available. Reality is much much more subtle, so subtle that seeing with the naked eye the expected anomaly in the tip path -even knowing what to look for- is really hard. Here we have a tailing loop in full glory. It is played at a slower pace than real speed. The tail could be used to illustrate a casting handbook; can you see the “bowled rod tip” anywhere?: Better to use a gif at 100 frames per second, that is 1/4 of the actual speed: Observe how even at a pace three times slower than reality we just can catch a glimpse of some anomaly in the tip path. So let’s use a visual aid to see what is exactly happening with the rod tip: This has cleared things up a little bit. Mainly two things come to my mind. First is that to get a tailing loop, even a huge one like that shown above, you only need to mess up a relatively short piece of the casting stroke. Second is a consequence of the previous observation and my main point so far: that this problem is so recurring due to the fact that a very small error, for just an instant, results in a surprinsingly big effect. It isn’t easy to feel, and then correct, things that happen in an instant, is it? It isn’t easy to detect for the caster himself nor for anyone else. The tailing loop depicted above is really huge. Let’s watch carefully another good one of more moderate size. Can you detect where in the stroke does the error happens even in slow motion? I can’t. The only way is playing the original video frame by frame to discover a veeery subtle dip and rise of the rod tip: Dip/Rise of the rod tip. It is worth to emphasize the “Rise” part since that motion is key in the formation of the transverse wave in the fly leg that we commonly call tailing loop. But that, together with some considerations about what is the ultimate cause of tails, is the stuff for a next article. P.S. The tailing loops shown here are real ones, nothing staged for the camera but involuntarily produced. The caster is a really fine one who drove from 400 km away for a course to improve his technique (I felt flattered and, at the same time, worried: would I deliver as expected?) His hauled casts were really nice. Then I took the camera and asked him to cast with the rod hand only. Removing the haul wreaks havoc with line control, but it is a fantastic exercise to educate our rod hand.
Tailing loops have the aura of a mysterious creature. Currently we know pretty well how they are formed but, at the same time, we can’t help to surprise ourselves when we get a tail now and then, no matter how experienced we are.
When casting for perfect loop control I will immediately detect any error in the stroke, my hand will easily feel any deviation from its intended straight line trajectory. The view of the fly leg getting out of plane in relation to the rod leg at the latest stages of the loop life does nothing but confirm what I already knew before stopping the rod: that I had messed up the stroke tracing.
Next cast I drive the rod butt straight but fail in accelerating it progressively. Now, though, I am only conscious of my fault when the dreaded tailing loop appears in the line; I don’t feel any clue in my hand. The mystery lies in the fact that the most subtle error in force application may result in a noticeable tail. An error as subtle that we can’t even feel it. The cast shown below is a good example of that.
What’s is the nature of that error in applying force? Just a spike in acceleration somewhere in the middle of the stroke. If the rate of acceleration decreases before reaching the end of the stroke the tip of the rod rises over its previous path; it is that rising what produces the transverse wave that we call tailing loop. Nothing mysterious but somewhat hard to grasp for some casters.
The main issue contributing to this confusion is the lack of differentiation between the concepts of velocity and acceleration and their respective roles in rod loading.
High rod speed doesn’t necessarily means big rod load. Load is a consequence of force, and force isn’t related to speed but to the rate of change of that speed, that is, to acceleration. Let’s take a simple view to that.
Let’s imagine that, at a given instant during the stroke, we have a rod butt speed value of 6 units, and in the previous instant the speed value was also 6 units. Rod butt speed is constant, no acceleration.
On another cast at a given instant the rod butt speed is just 5 units and in the previous instant the speed was 4 units. It has increased its speed from 4 to 5 units, that is, it has accelerated during that period time.
So we have a cast with a rod butt speed of 6 units against a cast with a rod butt speed of 5 units. Guess what? At that point in time the cast with the slower rod speed will show a bigger rod load!
This is a somewhat simplistic approach since there are other aspects at play which affect rod loading, such as air drag and angle between line and rod butt, but it is accurate enough to illustrate what we are dealing with.
We also know that any premature unloading will make the tip rise over its previous path creating the wave which will evolve into a tail. For the rod to unload the force applied to it must decrease. And here comes the fundamental part to understand this issue:
We don’t need to stop the rod to unload it; we don’t even need to decrease the speed applied to the rod for it to experiment some unloading!
Let’s imagine a casting stroke whose speed increases progressively. The rod butt speed profile measured at successive instants could be like this:
2, 4, 6, 8
This shows that the speed is increasing in a progressive way, accelerating at a rate of 2 units of speed per unit of time.
But then we measure the rod butt speed at the next two instants and find that its progression has changed:
2, 4, 6, 8, 9, 10
Speed continues increasing but acceleration has decreased from 2 units of speed per unit of time to only 1.
Remember that force is directly proportional to acceleration so a decrease in acceleration equals a decrease in force: the rod unloads correspondingly.
This is what has been traditionally called non-smooth, non-progressive or erratic acceleration of the rod. This is what gets our tailing loops flowing. And, IMHO, this is the reason why tailing loop formation is so subtle and difficult to feel.
One more apparent mystery with tails: when made on purpose even a casual glance to high speed video clearly shows that their alleged cause very rarely matches the real one. Even with pro casters. This leads to the idea that those long lists of tail-producing problems are just part of the story; they aren’t causes of tails by themselves, they just might be conducive to tailing loops… if you aren’t good enough at force application.
Tails, so easy to make when you don’t control and so hard to purposefully produce when you have refined your skills! So difficult in fact that even terrible timing or creeping usually fail to get the expected bad result when our force application is spot on.
In practice, the only real cause of tailing loops is a faulty acceleration, or a casting angle too narrow to accommodate the bend in the rod. In my experience the latter is much more common in casting instructors demos than in real life.
Now let’s make some analysis of the cast shown here.
Obvious thing number one: the forward cast starts toooo soon.
If we don’t wait for the line to straighten we are walking in dangerous terrain: we are not necessarily getting a tailing loop but we are conjuring it up.
So when the line straightens while the forward stroke is in progress the weight of the whole line shocks the rod and produces the tail, right?
Well, no, that is an explanation from the times when casters didn’t have the tools to check what is actually happening. As the gif above shows the hint of a wave in the line which will turn into a tail appears way before the backcast gets straight.
What makes a rushed timing more prone to tailing loops is much more subtle.
The cast shown here, with that early start of the stroke, accelerates just part of the line. By the time the loop is formed there is still line getting incorporated to the forward cast adding more weight to the launched line. This obviously decreases line speed. So to compensate for that lost line speed the bad timed cast must launch the line with a higher speed than in the case of a proper cast with the line fully straightened back. For the same stroke length and angle that implies necessarily a higher acceleration. In layman’s terms you must cast “faster”, and fast motion and control don’t come along very well. Conversely, going “slow” and smoothly increasing speed are a perfect matching pair.
Obvious thing number two: lack of hauling on the forward cast.
What helps enormously in getting control of the rod hand is… the line hand. Let’s get a little deeper into this.
To send the line and fly to a given distance we need to propel it with the required minimum speed. We can get that speed by the use of the rod hand only, or, by means of a haul, we can add extra speed to the line making the task of the rod hand easier: it doesn’t need to apply the same rate of acceleration, going “slower” with the rod hand is now enough to get the necessary line speed to reach the target. And by going “slow” it is much easier to get the proper progressive acceleration we are looking for.
In my view an efficient haul could have avoided the tailing loop even with the fault in timing present.
What are your views?
I think that the radical evolution in fly casting in the latest years has come, mainly, from two sources:
The availability of affordable high speed video equipment and the possibility of discussing technical issues with some casting geeks from all over the world… and in real-time.
The discussing part has been overdone. The learning experience that motion-freezing provides is still alive and kicking. The more I work with slo-mo the more I love it. Even a still camera with high speed capabilities can surprise you.
One of the milestones in the never ending road to casting improvement is when you discover that what you think you are doing is very different from what you are really doing.
Recently I spent two weeks of trout and grayling fishing with a good friend. Once in a while I like to put the rod aside and take the camera, specially when the fishing is as slow as in that particular afternoon. I shot a couple of series of stills at around 4 frames per second while he was fishing the water. Nothing related to casting technicalities, I just liked the light and the misty background.
When taking a look to the results I immediately remembered a statement from a recent conversation:
“I like to wait for the tug of the line in the backcast before starting the forward cast.”
So if some improvement could be derived from just getting a piece of new gear I think that, at this point in history, it is better to browse camera catalogs instead of fly rod ones.