Sweep, Loading… Unloading II



In the first article of this series we studied how the setting of a V-loop doesn’t put any load in the rod. The momentum of the line travelling backward is transferred to the water, without affecting the rod tip. In many spey casting technical works we find another purported source for that mythical rod pre-loading: the rod motion from the tilted sideways position at the end of the sweep into the more vertical position suitable for starting the forward cast, a maneouver also known as circling-up. A quote from the internet about this circling up and its consequences puts things in perspective:

It is intended to transfer the rodloading created during the Sweep, on through to the Forward Cast, in a continuous, uninterrupted fashion… no stopping of the rod, no load-unload-load action… thereby maintaining continuous loading of the rod.

As H.G. Wells wrote: It sounds plausible enough tonight, but wait until tomorrow.

Will tomorrow be able of invalidating plain logic?

As we have seen in the first part of this study rod bend comes from a force. After the sweep is finished the line moves on its own backward; the rod pulls on the line making it turn and a loop is formed.

– Well, for that to happen the rod has to exert a force on the line, and the line exerts the same force -action/reaction- on the rod in the opposite direction, right?

– Yes, of course.

– So the rod gets loaded, right?

– No, slo-mo says it doesn’t and so does physics.

Let’s take a look to the equation for force:

F = m.a

What this equation states is that force is directly proportional to mass (weight in layman’s terms) and acceleration (change in velocity). The bigger the mass the bigger the force needed to accelerate it; the bigger the acceleration the bigger the force applied. So for a force to be increased we could increase m, a or both.

So what happens to the mass of the line and its acceleration -and consequently to force and then rod load- in those two phases of spey casting known as sweep and circling-up?

During the sweep we are applying force to the whole length of line at play in order to form a loop; during circling-up we exert force only on the short piece of line which is actually turning around in the loop front, the part of the line changing direction but not on the rest of it. During the sweep we are pulling on a much bigger mass.

What about acceleration? During the sweep we have to accelerate the line significantly to form a loop; when circling-up the rod is not accelerating anymore, for the caster moves it to the key position leisurely, without the intention of applying any significant force. During circling-up we are pulling with much less acceleration.

The logical conclusion? The force bending the rod on the sweep is comparatively big and decreases hugely when the sweep ends. In fact the force exerted on the rod by the line during circling-up is so low that the amount of bend left is irrelevant. Some video to clarify things:


The following pictures correspond to three frames taken from the video above: they show both the difference in the mass the rod is pulling on, and the difference in rod bend between the sweep and the circling up.


The sweep applies significant force to the whole line. The rod is bent.


End of the sweep. No force applied to the rod or the line. Note how the line has lost tension and the rod is straight.


An instant during circling-up. The rod is pulling only on that piece of line inside the red circumference, so there is no appreciable bend in it.



More video:


Is it that important to be aware of these intricacies? It is, in my opinion, if only for one reason: if you train or fish focusing on getting some impossible pre-load, you won’t be paying attention to the things actually defining spey casting efficency, namely: minimum anchor, maximum live line in the V-loop, all that aligned with the target and as close to the forward rod tip trajectory as possible.

Sweep, Loading… Unloading I


Always shrouded in the mist of mystery, when popular casting mechanics focuses on spey issues it seems to enter the realms of magic.
It doesn’t help that the various styles of spey casting seem to compete in presenting their respective approaches as if they were different techniques, instead of just adaptions to some particular conditions.
Fortunately spey is spey, and physics is physics, and the latter governs the phenomena involved in the art of throwing a line with a pole in exactly the same way, whatever the brand, length or taper of your rod and line, and the waters and fish you are after, be it in Scandinavia or in the Pacific North West.

One concept is common to some of those schools, though: that efficiency in spey casting lies, in good part, in some kind of pre-load of the rod prior to the start of the forward cast.

An excerpt from a highly-regarded book will clarify this point:

With the fly/leader anchored to the water surface, the momentum of the forming “V” loop reloads the rod 180 degrees as a reaction.

So when the anchor touches down and the V-loop forms the rod gets automatically loaded. Apparently as the line is traveling backwards it will pull on the rod tip forcing it to bend. Pure logic, isn’t it?

The problem is that physics has the annoying habit of defying what at first sight looks like common sense. The good news is that high speed cameras, and a basic knowledge of Newton laws, help to open a more clear window into reality.
So in order to shed some light on this issue I did set up the following scenario:

  • Scott STS 7’6”#3 rod rigged with a #8 Barrio SLX line (equivalent to an AFFTA #10 one).
  • Line configuration in front of the caster similar to a perry poke with my right foot stepping on the line tip.
  • A sweep to set the V-loop.
  • Without a pause the rod is lifted up to the starting position for the forward cast in a continuous motion, and is stopped there.

Here you are:

An analysis of the casting sequence shown above is in order:

I start the sweep by accelerating the rod butt; I finish the sweep by decelerating the rod butt; as soon as the rod butt speed decreases, rod unloading starts.
Take notice that when I reposition the rod for the forward cast there is no load left in the rod.
After that the V-loop is fully formed and the line gets tight. That tension in the line loads the rod, right? Well, no, as shown by the video above the tight V-loop against the rod doesn’t put a bend on it.
Does it sound strange? Well, in fact basic physics tells us that it couldn’t be any other way. To understand this we have to look at the reason for rod bending, that is, force.

The sweep applies force to the rod, and the rod applies force to the line. Newton taught us that forces always come in pairs, it is what we know as action/reaction. So the rod applies a force to the line and the line reacts applying the same force to the rod in the opposite direction. Flexibility makes the rest.

The caster finishes the sweep by ceasing applying force; no force, no bend; the rod unloads itself. It is capital to take into account that the rod doesn’t need to be completely still to unload, that process happens before: as soon as the caster decreases rod butt velocity the rod unloads. Motion doesn’t necessarily mean force, only accelerated motion does mean force; a decreasing rod butt velocity means that it is not being accelerated anymore, and when acceleration disappears force disappears as well. In summary, a complete stop is not needed for the rod to unload.
At some point in the unbending process the line overtakes the rod tip, and the rod tip pulls on the line forcing it to turn around: a loop is born.

Back to the line in course of crashing against the water: it gets anchored and gets stopped.

What has stopped it? The water (in the case of the video above my foot).

Where does the fly leg momentum go? Obviously to the water, so that force of the crashing anchor is applied to the water, not to the rod!

An old slow motion video showing rod load when anchoring on water:

And another one:

But don’t take my word for it. A very easy experiment for you:

Rig a rod with line and leader. Lay the line in a perry poke configuration like that in the video. Take the end of the leader between your fingers. Make a sweep. Do you feel anything in your rod hand? Do you see any sudden loading? Where do you feel the tug of the line when it gets tight?

Quiénes somos? Hacia dónde vamos? Habrá cambio de 100 euros?


Tres amigos, tres enfoques distintos, y complementarios, del lanzado

No cabe duda de que no hay necesidad de entender los mecanismos de las cosas para que éstas sigan su curso. Todos somos capaces de conducir un coche con relativa habilidad, sin necesidad de tener idea de cómo funciona su motor.

Pero cuando se trata de “maestría”, en mi opinión, hay que empezar a hablar de otras cosas. Valga el ejemplo los pilotos de F1: ¿solo conducen? No, también saben un montón de mecánica, y ese profundo conocimiento parece la forma más eficiente de orientar a los ingenieros sobre qué es lo que hay que modificar para que las cosas funcionen lo mejor posible.

Entonces, en esto del lanzado y la maestría en su instrucción ¿cuánto hay que saber para enseñar?

Esa cuestión me plantearon hace unos años en una famosa feria de pesca a mosca cerca de Munich, donde nos reunimos un buen puñado de instructores de la IFFF.
Un candidato al título Casting Instructor, que solía seguir por encima alguno de los debates del foro de Sexyloops, me preguntó si realmente hacía falta profundizar tanto en cosas para él ininteligibles; si no era algo superfluo y una pérdida de tiempo. Salíamos de un hotel y justo enfrente había aparcado un BMW de los gordos. Le dije:
¿Crees que alguien podría disfrutar del placer de conducir un coche como ése, si antes no hubiera habido otros investigando sin descanso esas aburridas cosas de la física?

Mi opción personal es la de estudiar a fondo la mecánica del lanzado. Y no, no pretendo que otros instructores profundicen en esos temas que les quedan tan lejanos, me conformo con que no critiquen a los que sí nos interesamos por ellos. Al fin y al cabo ningún daño les hacen nuestros desvaríos, con que los ignoren es bastante; digo yo.

El Rodado Dinámico

En un artículo previo veíamos que el rodado dinámico es la evolución lógica del lance rodado convencional, la búsqueda de la máxima eficiencia. Recordemos esquemáticamente esa ineficiencia del lance rodado en contraposición al rodado dinámico.

Lance Rodado

  • Su ancla excesivamente larga nos roba mucha energía, desperdiciada en despegarla del agua.
  • La longitud de línea que realmente impulsamos hacia adelante con el golpe de lanzado es muy escasa, la mayor parte de la línea es un pasajero.

Rodado Dinámico

  • Ancla mucho más corta, solo la necesaria.
  • Mayor longitud de línea viva y, por tanto, menor de línea muerta.
  • Es el alma de todos los lances spey.

Ejecución de un Rodado Dinámico

  • Levantado: es una maniobra que lo único que pretende es liberar del agua la mayor longitud de línea posible. Cuanta más línea tengamos en el aire antes de comenzar la siguiente fase mejor, más limpio y fácil será el resto del proceso.
  • Barrido: se trata de un simple lance trasero al estilo belga (también conocido como lance oval) que se ejecuta con relativa poca fuerza para que el bucle no llegue a estirarse del todo, de forma que la punta de la línea caiga en el punto de anclaje.
  • Deriva: tras terminar el barrido, y mientras el bucle trasero va viajando por el aire, recolocamos la caña en un plano más cercano a la vertical preparándonos para el lance delantero.
  • Anclado: mientras derivamos se produce el anclado, anclado que coincide en el tiempo con la formación del bucle en D propiamente dicho.
  • Lance delantero: estaba a punto de escribir que el lance delantero se realiza igual que en un rodado convencional. No es cierto: en un dinámico el lance de presentación es mucho más relajado, controlado y elegante

Dicen que una imagen vale más que mil palabras, yo creo que en realidad las unas  complementan a las otras


Creo que aquí queda más clara la diferenciación entre levantado y barrido

Don’t Drag, my Fly, Drift Free!


Piling the cast for the nymph to drift deep and naturally

Anyone marginally interested in the casting world tends to regard fly casting and distance casting as synonyms. It is the same in fly fishing shows: anglers trying bunches of new rod models with their eyes fixed in the far end of the casting pond; it doesn’t make any difference if they are holding a 9’#9 devised for bonefish in the flats or a 8’6″#4 destined to spring creek finesse. I can’t blame them, in the end most of the visual material available on the net is about putting a fluff as far as possible.

What I did never get is why devoted casters and instructors (specially if they are river trout anglers) promote that very same connection.
I can’t think of a more harmful approach for the development of fly casting, at least in Spain. The river “trouter” doesn’t see distance casting as a problem solver for everyday issues presenting a fly, and though I agree that being proficient at long distances makes controlling the line at medium range much easier, that is a relationship that isn’t at all evident to fly fishers.

As you may suppose by now I am not a distance caster; take it as a mild way of saying that I am crap at putting a fly really far away. In my view two fundamental elements pave the way to becoming a distance expert: a single family house and a big garden outside; I lack both of them. The possibility of keeping a rigged rod behind the door at all times helps a lot. Practice makes perfect and for getting your fly thirty plus meters away you need a lot of it!
I have my training lawn at 35 minutes from home, which means more than an hour just to get there and back; add some substantial time for the actual practice and the result is that my opportunities for training aren’t many. But even having a practice field close to my house I doubt I’d be much better in the distance game. No that I wouldn’t be very happy reaching astronomical distances, but spare time is limited and I prefer to spend it improving drag-free drift techniques, which, when looking for real proficiency, are as time consuming as distance itself but much more in tune with the kind of fishing I practice the most.

Have I missed being a good distance caster when fishing? Of course I have! Baltic pike and Patagonia sea-run brown trout come to mind. But I have lost count of how many times I have missed the ability of getting a perfect drift of my fly in the maze of micro-currents of my favorite fishing venues.

Around a year ago I was mentoring a candidate for the IFFF CCI title. After months of in-depth looking at the theoretical test it came the day to check for weaknesses in the practical part. The first tasks on loop control were good. Then I asked for the Reach Cast (or a Reach Mend by the current IFFF standards). He barely moved the rod tip sideways as without any purpose, resulting in a very poor line configuration on the ground, try after try.

You have to make each cast with authority not only for the examiners to see but when fishing as well” I said.

Then an idea started turning around inside my head.

Do you know what the practical uses for the Reach are? I asked.

Practical uses? I thought it was an exercise, something for the examiner to check if you have a good control of the line!” He replied.

Amazing! I can’t think of a single day on the river not sending dozens of Reachs out there, and there I was with a would-be casting instructor who didn’t have a clue about one of the most practical fishing casts available!
Of course he was very good at sending the fly thirty plus meters away.

In my opinion this shows that we, casting instructors, are approaching things in a wrong way. For instance, the invention of “trick casts” intended just for showing off doesn’t exactly help in reconciling -in the eyes of the fishing community- casting with fishing as the two sides of the same coin they actually are.

So here we go with some dry fly downstream drag-free presentations by master angler Zeljko Prpic.

A Hundred Thousand



A hundred thousand? Of what? you ask.
Video plays on my Vimeo account.

Not exactly a record, to be honest. Popular videos on the net have that amount of visualizations in a month, some of them in even in a week! It took six years for my clips to get to that number!

And although it is a ridiculous amount by current standards I feel satisfied and surprised.

Filming fly casting things, focusing that work in fly casting mechanics, which is of interest just to the minority of the minority, puts that “hundred thousand” in perspective.
Must I know about casting mechanics in order to be a good caster? Some guy asked me in a fly fair in Germany some years ago.
Of course not, I replied. Do you see that beautiful BWV parked there? You don’t need to know how to design a car engine to be a good driver, not even need to have a clue about how it works, but if you like driving you should be grateful to those who spent their time trying to grasp the  physics of all the amazing things inside that hood. Without their apparently ridiculous and boring efforts you wouldn’t have the opportunity of enjoying a beautiful machine like that; not even the chance of using the most simple of all automobiles.

Thank you for having such a strange interest in these weird things and, please, keep watching!

There is more to come.