Lifting the line (principle 2) of Kreh's book

ShawnT · 03-20-01, 04:48 PM

Regarding Modern Fly Casting Method (1991) yet again . . . (If I've exceeded my question limit, apologies. If I even get one answer, I'll be happy . . .)

Regarding principle 2 of Kreh's methodology, he states
<BLOCKQUOTE>quote:</font><HR>On the back cast, the end of the line should be lifted from the surface of the water before the cast is made.<HR></BLOCKQUOTE>

I'm probably being a little dense in this part. But I find it hard to comprehend, particularly on long casts, being able to lift the line from the water before the cast is started -- particularly if you're working with sinking line. Or is he specifically talking about the acceleration portion of the cast? (And is it the acceleration part where he is talking about the "dart throw" as Kent once described it, or earlier in the cast?)

Later in the book it seems that he's describing lifting the line at the same time as the back cast which would make sense. But that seems contradictory to the information in the "principle" itself.

Any thoughts?

dredger · 03-20-01, 07:08 PM

The point is to get the line straight before beginning the cast. Start with the rod tip low and strip line until the line is straightening on the water. At this point, beginning the cast by lifting the rod tip will cause all of the line to start moving at the same time.

Here is an analogy. Watch a line of cars starting off at a traffic light when it turns green. All of the cars do not start moving at the same instant in time. Driver two starts moving after a reaction delay, and driver three after a reaction delay to driver two's movement. If those cars are points on a fly line, a bad cast will follow. Every point on the fly line should start to move AT THE SAME TIME when the rod tip starts up, otherwise part of the casting stroke will be wasted, and the all of the line will not accelerate as a unit.

In this first part of the stroke, the line speed is increased slowly. After the line starts to clear the surface of the water (the amount will vary with the length of line out, line weight, rod action, etc), the acceleration part of the stroke begins.

Back to physics 101. Force = mass x acceleration. Acceleration is the rate of change of velocity. If the rod tip is moving at a constant velocity, there is no acceleration.

The first part of the cast gets the line in a straight line so that it can be accelerated in a straight line. Once a sufficient amount of line has cleared the water, you can begin accelerating without causing a water spray that will spook fish. The line that remains on the water is resisting the motion because of the surface tension of the water. This resisting force, and the inertia of the fly line cause the bending of the rod tip as the rod is accelerated. This bending of the rod tip is called "loading the rod".

Energy is being stored in the rod when the rod is being bent. This energy will be released to the line at the end of the casting stroke and continue to accelerate the line until the rod finishes flexing in the opposite direction. This is referred to as the rod "firing".

Lefty calls the acceleration phase of the stroke the "speed up" part. Remember, you are not accelerating unless the speed continues to increase (A note to the engineers and physicists, I am using speed here, a scalar, instead of velocity, a vector, for the sake of simpicity. Acceleration also occurs if speed remains constant, but direction changes.)

You want all of the points on the line to accelerate at the same rate and in a straight line.

When you get toward the end of the stroke and approach the "stop", the tip of the rod must move in a slight downward arc to form the "loop". If the rod tip moves in a perfectly staight line and then suddenly stops, the line will crash into it. This is one of the causes for "tailing loops". Tailing loops can also be formed by accelerating too soon.

The size of the loop is determined by the distance the rod tip drops at the end of the stroke.

A good exercise is to tie about 6 feet of ribbon onto a stick or rod tip. Wave it around like a gymnast in the olympics and watch what the ribbon does. If you make circles with the tip of the stick, the ribbon makes a circle. If you make s curves with the tip of the stick, the ribbon makes s curves. If you move the tip of the stick in a straight line, the ribbon moves in a straight line. Your fly line will act in exactly the same way!!!

Stinkbait · 03-20-01, 07:08 PM

I saw Lefty talk about this at the Shallow Water Expo. What he is saying is start your backcast with your rod pointing toward the water and your line tight. Then you will be lifting the line from the water in the slow initial start of the cast and the energy from the acceleration portion of your backcast will be imparted to the line instead of wasted lifting the line out of the water. It is difficult to cast a sinking line without first retrieving it to the surface.

ShawnT · 03-20-01, 07:48 PM

Well, a classical language background doesn't translate all of this very well . . .

BUT

It struck me as this was one of the primary parts that I needed to pay attention to:

<BLOCKQUOTE>quote:</font><HR>"The first part of the cast gets the line in a straight line so that it can be accelerated in a straight line. Once a sufficient amount of line has cleared the water, you can begin accelerating without causing a water spray that will spook fish."<HR></BLOCKQUOTE>

Has this been my biggest problem?

Most of what I have learned so far has been to use the pressure of the water on the backcast to load the rode to give it the flex and spring. But the Kreh book seems to indicate that I shouldn't be using the friction of the water on the backcast at all.

Or perhaps have I been misunderstanding that concept the entire time?

Kent · 03-20-01, 07:49 PM

More than a few Lefty fans here, huh, Shawn. And I think you've gotten your answer.

The line is lifted before "beginning the cast" (read casting motion) to 1) -prevent ripping line from water & spooking fish and 2) - to free it from the surface tension so that casting motion is not wasted in pulling free from surface tension. On one hand, you could consider this part of the cast as you begin to move the rod up very slowly til it clears the water (or at least until only the fly & part of leader is on the water). If you have a very long line out, it can help to lean forward and down and lower the rod parralel to and almost down to the water, the begin raising the rod to waist height still parralel to the water, then meld immediately into the (pre)casting motion to clear the line from the water. This is all one motion (if it's not the line will begin to drop slack between the tip and the water), but the actual casting motion doesn't start until the line is lifted from the water.

With sinking & sinktip lines, you can decrease the amount of line that must be retreived by roll casting ( sometimes more than once) to bring the line to the surface.

With big surface poppers, a roll cast may be the only way to free the fly from the surface tension (short of retreiving almost all of the line).

The principle here is the same - you must get the end of the line moving (read the entire line moving at the same speed) before you can make the cast.

One note on loops - the size of the loop is determined by the distance of the speed-up-and-stop. It can be opened by dropping the tip at the end of the cast, but it can only be tightened by decreasing the length of the s-u-a-s.

------------------
Kent
Flyfishing West Georgia & Beyond

Kent · 03-20-01, 07:54 PM

Shawn - you got there before me.

No, generally speaking, you should not use the friction of the water to load the rod. There is a "water haul" - but that's another subject and is usually reserved for the forward cast.

The problem with it is that you get the shock effect when the fly rips lose from the water, not the smooth acceleration you want. Plus you may spook the fish.

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03-20-01, 04:48 PM	#1
ShawnT Native Join Date: Jan 2000 Location: Columbus, GA Posts: 324	Regarding Modern Fly Casting Method (1991) yet again . . . (If I've exceeded my question limit, apologies. If I even get one answer, I'll be happy . . .) Regarding principle 2 of Kreh's methodology, he states <BLOCKQUOTE>quote:</font><HR>On the back cast, the end of the line should be lifted from the surface of the water before the cast is made.<HR></BLOCKQUOTE> I'm probably being a little dense in this part. But I find it hard to comprehend, particularly on long casts, being able to lift the line from the water before the cast is started -- particularly if you're working with sinking line. Or is he specifically talking about the acceleration portion of the cast? (And is it the acceleration part where he is talking about the "dart throw" as Kent once described it, or earlier in the cast?) Later in the book it seems that he's describing lifting the line at the same time as the back cast which would make sense. But that seems contradictory to the information in the "principle" itself. Any thoughts?

03-20-01, 07:08 PM	#2
dredger Native Join Date: Jun 1999 Location: Lula, GA, USA Posts: 209	The point is to get the line straight before beginning the cast. Start with the rod tip low and strip line until the line is straightening on the water. At this point, beginning the cast by lifting the rod tip will cause all of the line to start moving at the same time. Here is an analogy. Watch a line of cars starting off at a traffic light when it turns green. All of the cars do not start moving at the same instant in time. Driver two starts moving after a reaction delay, and driver three after a reaction delay to driver two's movement. If those cars are points on a fly line, a bad cast will follow. Every point on the fly line should start to move AT THE SAME TIME when the rod tip starts up, otherwise part of the casting stroke will be wasted, and the all of the line will not accelerate as a unit. In this first part of the stroke, the line speed is increased slowly. After the line starts to clear the surface of the water (the amount will vary with the length of line out, line weight, rod action, etc), the acceleration part of the stroke begins. Back to physics 101. Force = mass x acceleration. Acceleration is the rate of change of velocity. If the rod tip is moving at a constant velocity, there is no acceleration. The first part of the cast gets the line in a straight line so that it can be accelerated in a straight line. Once a sufficient amount of line has cleared the water, you can begin accelerating without causing a water spray that will spook fish. The line that remains on the water is resisting the motion because of the surface tension of the water. This resisting force, and the inertia of the fly line cause the bending of the rod tip as the rod is accelerated. This bending of the rod tip is called "loading the rod". Energy is being stored in the rod when the rod is being bent. This energy will be released to the line at the end of the casting stroke and continue to accelerate the line until the rod finishes flexing in the opposite direction. This is referred to as the rod "firing". Lefty calls the acceleration phase of the stroke the "speed up" part. Remember, you are not accelerating unless the speed continues to increase (A note to the engineers and physicists, I am using speed here, a scalar, instead of velocity, a vector, for the sake of simpicity. Acceleration also occurs if speed remains constant, but direction changes.) You want all of the points on the line to accelerate at the same rate and in a straight line. When you get toward the end of the stroke and approach the "stop", the tip of the rod must move in a slight downward arc to form the "loop". If the rod tip moves in a perfectly staight line and then suddenly stops, the line will crash into it. This is one of the causes for "tailing loops". Tailing loops can also be formed by accelerating too soon. The size of the loop is determined by the distance the rod tip drops at the end of the stroke. A good exercise is to tie about 6 feet of ribbon onto a stick or rod tip. Wave it around like a gymnast in the olympics and watch what the ribbon does. If you make circles with the tip of the stick, the ribbon makes a circle. If you make s curves with the tip of the stick, the ribbon makes s curves. If you move the tip of the stick in a straight line, the ribbon moves in a straight line. Your fly line will act in exactly the same way!!!

03-20-01, 07:08 PM	#3
Stinkbait Native Join Date: Jul 1999 Location: Atlanta, Ga, USA Posts: 635	I saw Lefty talk about this at the Shallow Water Expo. What he is saying is start your backcast with your rod pointing toward the water and your line tight. Then you will be lifting the line from the water in the slow initial start of the cast and the energy from the acceleration portion of your backcast will be imparted to the line instead of wasted lifting the line out of the water. It is difficult to cast a sinking line without first retrieving it to the surface.

03-20-01, 07:48 PM	#4
ShawnT Native Join Date: Jan 2000 Location: Columbus, GA Posts: 324	Well, a classical language background doesn't translate all of this very well . . . BUT It struck me as this was one of the primary parts that I needed to pay attention to: <BLOCKQUOTE>quote:</font><HR>"The first part of the cast gets the line in a straight line so that it can be accelerated in a straight line. Once a sufficient amount of line has cleared the water, you can begin accelerating without causing a water spray that will spook fish."<HR></BLOCKQUOTE> Has this been my biggest problem? Most of what I have learned so far has been to use the pressure of the water on the backcast to load the rode to give it the flex and spring. But the Kreh book seems to indicate that I shouldn't be using the friction of the water on the backcast at all. Or perhaps have I been misunderstanding that concept the entire time?

03-20-01, 07:49 PM	#5
Kent Hall of Fame Member Join Date: Sep 1998 Location: LaGrange, GA Posts: 1,489	More than a few Lefty fans here, huh, Shawn. And I think you've gotten your answer. The line is lifted before "beginning the cast" (read casting motion) to 1) -prevent ripping line from water & spooking fish and 2) - to free it from the surface tension so that casting motion is not wasted in pulling free from surface tension. On one hand, you could consider this part of the cast as you begin to move the rod up very slowly til it clears the water (or at least until only the fly & part of leader is on the water). If you have a very long line out, it can help to lean forward and down and lower the rod parralel to and almost down to the water, the begin raising the rod to waist height still parralel to the water, then meld immediately into the (pre)casting motion to clear the line from the water. This is all one motion (if it's not the line will begin to drop slack between the tip and the water), but the actual casting motion doesn't start until the line is lifted from the water. With sinking & sinktip lines, you can decrease the amount of line that must be retreived by roll casting ( sometimes more than once) to bring the line to the surface. With big surface poppers, a roll cast may be the only way to free the fly from the surface tension (short of retreiving almost all of the line). The principle here is the same - you must get the end of the line moving (read the entire line moving at the same speed) before you can make the cast. One note on loops - the size of the loop is determined by the distance of the speed-up-and-stop. It can be opened by dropping the tip at the end of the cast, but it can only be tightened by decreasing the length of the s-u-a-s. ------------------ Kent Flyfishing West Georgia & Beyond

03-20-01, 07:54 PM	#6
Kent Hall of Fame Member Join Date: Sep 1998 Location: LaGrange, GA Posts: 1,489	Shawn - you got there before me. No, generally speaking, you should not use the friction of the water to load the rod. There is a "water haul" - but that's another subject and is usually reserved for the forward cast. The problem with it is that you get the shock effect when the fly rips lose from the water, not the smooth acceleration you want. Plus you may spook the fish.