A fishing roll cast: look at the lack of tension in the fly leg of the D-loop
I was trying hard to follow exactly what I had been reading on all those books. The roll cast was an easy one —authors said— in fact easier than an overhead cast because you get rid of the backcast part. However, when practicing it my results were awful, to say the least.
A guy waving a rod in the middle of an urban park is like a priest on top of a mound of lime. Fortunately, the guy coming to me this time was a fly fisher.
—Are you trying a roll cast? It is easy, I use it everyday on the river.
—Show me, please!
… and the cast ended in a heap of line.
—I don’t know what happens, maybe it is your gear —he said.
Looking for an answer to that frustration; what I found was mostly something along these lines:
“It’s best to practice this cast on water because the water creates the friction and drag necessary for a good roll cast. The friction of the water on the line in the roll cast helps load, (bend) the rod.“
Yes! That corroborated what I had been studying so far! Rod and line were the equivalent of bow and arrow: the rod gets bent —loaded— and it propels the line when unloading.
This approach leads to a widespread conclusion: any action or thing contributing to rod loading —sometimes only in appearance— is good by itself, while most of the problems with failed casts have their source in an “insufficiently loaded” rod.
But this isn’t how a fly rod actually works —in fact this view is totally misleading when trying to explain a good bunch of casting phenomena— however, since the bow/arrow model is still the prevalent view in the casting scene, it is worth examining rod load in spey casting. So the present article comes as a complement of this one about bend when the anchor settles, and this other one on the effects of circling-up after the sweep.
The following video is the second most viewed one of my Vimeo channel, and probably one of the less well understood. Let’s analyze what that experiment shows. What I am using to make some roll casts is an Echo Micro Practice Rod, whose “line” consists of braided cotton cord with a short piece of red wool as the “leader”. A tiled floor makes for the perfect scenario for the experiment. Since when casting on water the anchor is said to be the main actor providing rod load, what happens to rod bend when we have no anchor at all?:
Another roll cast from a different point of view:
What is happening on those clips? We have a very slippery floor that allows the line lying on it to slip freely, with almost no resistance due to the very low friction provided by the polished surface. As the current view on anchor and rod load states, the water “grip” on the anchor provides the resistance against the rod is moving, putting a bend on it. The rod pulls on the anchor and the anchor reacts and pulls on the rod bending it. But is that what actually happens?
Let’s address the main factor to understand this issue: during the casting stroke tension on the fly leg of the D-loop is very very small, that is, the force exerted by the moving D-loop on the anchor is very small, so small in fact that the anchor on a tiled floor remains in place during the whole casting stroke. It is important to notice that the line starts slipping backward only when the casting stroke is finished; the turning D-loop is able of making the anchor slip only when it is very close to the line end, when its small force is exerted on a shorter piece of cord, whose small mass opposes much less resistance to the pulling.
A fly rod bends due to action/reaction: we apply force to rod and line and these react due to their inertia —a body that isn’t in motion wants to remain still and opposes itself to any force trying to put it in motion; inertia we call it—, trying to oppose that force. Since the rod is flexible it bends, gets “loaded”. But, as those videos above show, if the fly rod pulling on the rod leg of the D-loop is unable of moving that super slippery anchor it is because it isn’t actually pulling on it, and if the rod doesn’t pull on the anchor the anchor doesn’t pull on the rod!; no pulling, no load!
And what about the bend in the rod on those slippy anchor casts? As we can see the rod gets loaded even without the supposed effect of the anchor. If it isn’t the anchor, what is it that provides that load? Just action/reaction, as explained above. When the stroke ends the rod has been pulling only on the piece of line that forms the rod leg of the D-loop, but not on the rest, that is, not on the piece of line lying on the floor. So that rod bend comes from the reaction of the rod itself and from the reaction of the rod leg of the D-loop only. That length of line that the caster has impulsed during his casting stroke is what I call live line, as opposed to the dead line which forms the fly leg of the D-loop; this dead line contributes nothing to our cast, it is just a passenger, a payload. But this is an interesting aspect that will be analyzed in another article.
OK! —you say —but that is just an experiment, what happens in a real cast?
As shown on this clip, on water we face the same phenomenon: the anchor slips after the casting stroke is finished:
The following picture was shot in a real fishing situation. It shows that even with a water anchor, tension in the fly leg of the D-loop is so low that that piece of line isn’t tight at all:
Another clip showing how small is the force exerted by the rod leg on the fly leg:
So, if the anchor’s function isn’t rod loading, what is its role? The following video addresses this. Take notice of the instant in which the anchor starts sliding backward and its effect on the front loop speed and shape:
Conclusion? Don’t think of rod load, just concentrate in as long a live line as possible, with it, V-loop and anchor pointing in the direction of the target. And consider rod load just as a by-product of a well executed casting stroke.