Fly-rod mechanics

Fly-Rod Mechanics

In most types of conventional fishing, such as spin fishing and bait casting, the angler uses a rod to cast a lure or bait that is attached to a very thin, light line. Because it has weight, the lure or bait could be thrown a good distance by hand, without the rod. In conventional fishing, you’re essentially hurling a rock that’s attached to a string. In fly-fishing, the “lures” we cast—usually artificial insects and baitfish imitations—are made from bits of hair and feather and are virtually weightless. We could not throw them by hand. The weight we cast in fly-fishing is contained in the fly line itself; it is a long, flex- ible weight that unrolls through the air in an open-ended loop. The artificial fly is attached to the end of a tapered monofilament leader; the thick, butt end of the leader is attached to the tip of the fly line. The weightless fly is carried through the air by the energy of the un- rolling loop. The other major difference between fly-fishing and conventional fishing is that fly-fishing requires you to cast backward as well as for- ward. In fly-fishing, the basic cast requires a minimum of two casts to deliver the fly—a back cast and a forward cast (see next page, bot- tom)—as compared with conventional fishing, in which the lure is propelled on the forward stroke only. One of the great obstacles en- countered by conventional anglers making the transition to fly-fish- ing is learning to cast backward. In the basic fly cast, the fly rod describes an arc (see next page, top). This is not the simple V arc described by a metronome, how- ever. Because the fly-caster moves his rod arm and hand to bring the rod through the stroke, the base of the arc is flat [_ /]. Because of the rod’s length, the tip of the rod moves a much greater distance during the stroke than does the butt of the rod. For our purposes, we can define the distance your rod hand moves during the cast as the stroke length, and we can define the distance the rod tip moves during the cast as the casting arc.

The basic fly cast describes an arc that has a flattened base. The base of the arc represents the distance the rod hand moves during the casting stroke, while the top of the arc repre- sents the distance the rod tip moves during the stroke.

The basic fly cast requires a minimum of two strokes—both a back cast and a forward cast—to deliver the fly.

Loading and Unloading the Rod The fly rod has been described a number of ways by various writers. Some writers have called the fly rod a spring. Others have called it a lever. Having no background in engineering or physics, I’m not sure what a fly rod is, in mechanical terms—nor do I think it’s necessary to know to learn how to cast one. The modern fly rod is a tapered graphite shaft; it is flexible and bends progressively from the tip downward during the casting stroke. It may help you, at certain times in your learning, to think of the fly rod as a spring, and at other times to think of it as a lever. However, the analogy I’ve found most useful to explain—and understand— the way a fly rod works is to describe it as being similar to a bow and arrow. To shoot an arrow, the archer pulls the bowstring to draw the bow into a bend. Drawing the bow into a bend stores potential energy along the length of the bow. When the archer releases the bowstring, the bow springs back into position, and its energy is transferred into the arrow to propel it. Drawing the bow into a bend stores This is similar to the way a fly rod works. To cast the fly line, you potential energy in the bow.

must first pull the rod into a bend. Unlike the archer, however, the fly caster has no fixed point to draw against to bend the rod. To make the rod bend, you must pull against the weight and inertia of the fly line. This is called loading the rod (see illustration next page). Loading the rod stores potential energy along the length of the rod. To com- plete the cast, you must force the rod out of its bend by stopping it abruptly, which causes the energy stored in the bent rod to transfer into the fly line, propelling it either forward or backward. (In terms of fly-rod mechanics, the forward cast and the back cast are identical casts delivered in opposite directions.) Forcing the rod out of its bend is called unloading the rod. Without question, loading and unload- ing the rod together comprise the most important aspect of fly cast- ing. Loading and unloading the rod properly is critical for distance casting: the amount of potential power you can put into any cast is determined by how deeply you can load the rod, and the amount of power you transfer from the loaded rod into the fly line is determined by how well you unload the rod. Loading and unloading the rod is the most important aspect of fly casting, but it’s also the most difficult to learn. Many fly-fishers never learn to load and unload the rod properly, or never do it as well as they might. The vast majority of fly-casting problems can ultimately be traced to difficulties with loading and unloading the rod. Loading and unloading the rod—pulling the rod into a bend, and When you release the bowstring, the then stopping the rod abruptly to force it out of a bend—is a decep- bow springs back into position, tively simple concept, so let’s take a close look at it. transferring its energy into the arrow Whether it’s lying on the ground or on the water, whether it’s in ato propel it.

straight line in the air behind you or in front of you, the fly line, for all intents and purposes, is at rest. Newton’s law of inertia states that objects at rest tend to remain at rest; they resist our attempts to move them. When you use the rod to try to move the fly line, the inertia of the fly line resists. This resistance pulls the rod into a slight bend. Now you’ve started the fly line moving toward the rod tip. To continue to pull the rod into a bend, you have to continue to use the line’s inertia and move the rod tip faster than the speed of the following fly line. To continue to load the rod, you must constantly move it faster: you must accelerate the rod tip over the entire casting arc. Because the fly rod must accelerate continuously throughout the casting arc, many fly-fishers conclude that fast casting strokes are desirable. This misleading notion contributes to many casting problems, particularly with saltwater fly-fishers who are trying to add distance to their cast. Imagine a fly rod with 30 or so feet of line outside the rod tip. Imagine also that you could move this rod (through a vacuum) at a constant speed of 500 miles per hour. Because the rod and line are both traveling at the same speed, the rod will not

top “Top.” The fly caster uses the weight“Middle.” Stopping the rod abruptly“Bottom.” After the rod unloads, and inertia of the fly line to pull theforces the rod out of its bend. Thethe airborne fly line continues to soar rod into a bend. This is called loadingenergy stored in the bent rod getsforward. When the fly line passes the rod. Loading the rod stores poten-transferred into the fly line, pro-over the rod tip, a loop forms. Nar- tial energy in the rod.pelling it forward (or backward, for arow or tight loops are desirable be-

top “Top.” The fly caster uses the weight“Middle.” Stopping the rod abruptly“Bottom.” After the rod unloads, and inertia of the fly line to pull theforces the rod out of its bend. Thethe airborne fly line continues to soar rod into a bend. This is called loadingenergy stored in the bent rod getsforward. When the fly line passes the rod. Loading the rod stores poten-transferred into the fly line, pro-over the rod tip, a loop forms. Nar- tial energy in the rod.pelling it forward (or backward, for arow or tight loops are desirable be-

back cast). Forcing the rod out of itscause they transfer energy more effibend is called unloading the rod.ciently than wide loops.

bend. For the rod to bend, the rod tip must always be moving slightly faster than the following fly line. It’s not speed itself that loads a rod, it’s the gradual increase in speed: the acceleration. All good fly casts begin slowly. What’s important is that they gradually, continually gain speed over the entire stroke. An efficient fly-casting stroke be- gins loading the rod as soon as the rod tip begins to move through the casting arc. At no time during the casting stroke should the rod move at a constant speed. To load the rod properly, you must accelerate it smoothly throughout the entire stroke. Once you’ve loaded the rod, unloading it properly will ensure that you transfer all the energy from the bent rod into the fly line. The proper way to unload a fly rod is to stop the rod abruptly, which trig- gers the release of energy in the loaded rod: the rod tip springs for- ward (or backward, for a back cast), and the rod’s energy is transferred into the fly line to propel it. Affecting a positive stop is critical to unloading the rod properly. If you bring the rod to a gradual stop, the rod will begin unloading while you’re slowing down. If the rod decelerates before coming to a stop, much of its power is lost. Imagine an automobile traveling at 50 miles per hour. If the driver were to apply the brakes, the car would come to a gradual stop over a distance. Imagine this same automobile moving at a speed of 50 miles per hour and then hitting a brick wall. The car would stop dead, and every object in the car that wasn’t fastened down would be- come a projectile. That’s essentially what’s happening when you un- load the rod properly: the abrupt stop transforms the fly line into a projectile. What makes the fly-casting stroke difficult to learn is that it’s dif- ferent from almost every other stroke you can imagine. A proper fly- casting stroke seems to go against common sense. When serving a tennis ball or driving a golf ball, you hit the ball hard and follow through with power. When pitching a fastball or throwing a javelin, you follow through with power. The fly-casting stroke is different from virtually every other sports stroke in that it concludes with an abrupt stop. Many beginners (as well as many experienced fly-fishers) have trouble at this stage, I believe, because they envision the fly-casting stroke as a throw. They use the rod simply as an extension of their arm to “throw” fly line as they would throw a ball: following through with power. Even if they load the rod well, these fly-fishers sabotage their casts by failing to stop the rod abruptly to unload it properly. They bypass the rod’s spring-flex action and simply hurl line forward and backward. If you bypass the rod this way, you might eventually be able to throw 40 or more feet of fly line—but it will never be effort- less, graceful, or precise. In short, you’ll never be able to “throw” line as well—or as far—as you can “cast” it.

All good fly casters, regardless of their “style” or “method,” have learned to load and unload the fly rod properly. This is the foundation upon which all other fly-casting skills are built. As I’ve said, loading and unloading the rod is the single most difficult aspect of fly casting to learn. Once you learn it, however, everything else will be relatively easy.

Forming the Loop

As I explained in the previous section, a good casting stroke enacts a smooth, continuous acceleration and concludes with an abrupt stop. When the rod stops on the forward stroke and the rod unloads, the airborne fly line, which you’ve been pulling from behind you, continues to soar forward. The line is anchored at the rod tip, and when the following fly line passes over the rod tip, a loop forms (see illustration on page 10). The bottom leg of this loop remains anchored at the rod while the top leg continues to unroll forward. To become a good fly caster you must learn how to form tight loops. A tight loop is the most efficient way to transfer the rod’s en-

straight path

The cast will assume whatever shape the rod tip has traveled. If the rod tip moves along a straight path, the cast will assume a narrow or tight loop . . .

ergy toward the target, because a tight loop focuses all of the energy from the cast into a very narrow area. Forming a tight loop is critical to distance casting: the tighter the loop you can form, the farther and faster your cast will travel. Also, tight loops are less wind resistant than wide loops and are a must for casting into a wind. The size of the loop is determined by the position of the rod tip relative to the path of the following fly line at the conclusion of the casting stroke. In a good fly cast, the rod unloads just beneath the path of the following fly line. The fly line that is anchored at the rod tip forms the bottom leg of the loop. The rod tip, when it recoils back into a straight position, is only several inches beneath the path of the following fly line—that is, the top leg of the loop. A good loop looks like a narrow U or V that has been tipped on its side. If, at the end of the casting stroke, the distance between the rod tip and the path of the following fly line is significant, then the loop will be wide. Wide loops transfer power inefficiently; they don’t travel as far, or nearly as fast, as narrow loops. Also, wide loops are more wind resist- ant than narrow loops and are ineffective when casting into the wind. To form a tight loop you must accelerate the rod tip along a straight-line path throughout the casting arc, and then drop it only curved path . . . but if the rod tip moves in a curved or convex path, the cast will assume a wide loop or nonloop.

slightly at the end of the stroke as you stop the rod to unload it. It’s important to remember that the cast will assume whatever shape the rod tip has traveled. If the rod tip moves along a straight path, the cast will assume a narrow or tight loop. But if the rod tip moves in a curved or convex path, the cast will assume a wide loop or nonloop (see previous page). As we’ve said, a good casting stroke begins slowly and accelerates smoothly. If you use too much speed at the beginning of the stroke, you’ll shock the rod and destroy the cast. Very often a short, jerky casting stroke causes the rod tip to move in a concave path. This, in turn, causes the rod to unload above, rather than below, the path of the following fly line. This results in what’s known as a tailing loop or

A short, jerky casting stroke often

causes the rod tip to move in a con-cross-loop: the legs of the loop are crossed rather than open-ended. cave path. When this happens, theTailing loops can tie knots in your leader (fly-fishers refer to these as

wind knots, although they have nothing to do with the wind). In severe cases, tailing loops can also tie knots in your fly line. On short

rod will unload above, rather than below, the path of the following fly line. This causes what is known as a

tailing loop or cross-loop; that is, thecasts, tailing loops are most often caused by jerky casting stokes. Re- legs of the loop are crossed rathermember that on a good casting stroke the rod accelerates smoothly.

The loop of line is the single best piece of data to analyze your cast, for it always tells you exactly what the rod tip did during the casting

than open-ended. Tailing loops are responsible for so-called wind knots and, in severe cases, can even tie knots in your fly line.stroke.