Fly line tension

I've often wondered about the "climbing loop". I think it might/must be due to the shape of the cast. If the cast "nearly enough" resembles a cross-section of an airplane wing, even off plane, wouldn't the fly leg have lift? We know that wings of many different lengths have lift. Why not a wing that is only the length of the thickness of a fly line as it moves through the air?

Back on subject: I think the Kinetic energy of the cast is stored for the length of the cast at the VERY point of turn-over from rod leg to fly leg. That is the only point where energy is being transferred after the movements of the cast have been completed.

You may be correct with your statement on energy, however, Kinetic energy is energy being released as work is performed ...not stored energy which is usually referred to as, Latent energy. Gordy

"If the tension is zero at the fly, then what pulls the fly in the direction of the cast ? Gordy"

Good question. I was assuming a weightless, volumeless fly - the sort of fly that won't catch a big fish. Put a real fly on and you increase the Tension in the system.

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In the real world, there is not a fly which is totally weightless and/or volumeless.

As I see it, it is simply a matter of degree. Even a # 32 sparsly dressed midge has some mass and inertia. Therefore, I feel that at least a tiny degree of tension is needed to move it. Much more with your example of the large fly.

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Maybe I am chiming in late, but the use of the term tension has broadened since my last check. When we use tension to describe the changes in loop shape during transition from fly leg to rod leg, or in the existence of tension when the line is affected by counter-flex and rebound, there seems to be an expansion of the terms definition. This might be a good juncture to define Tension to prevent any over-use or mis-use of an otherwise simple term/definition for the MCCI candidates.

I understand that tension can be considered any pulling of the line, as in making a forward casting stroke with the line following the direction of the rod tip. I like what Jim V. said: " Rod moves the line forward under tension".

I understand that there is a great degree of resistance in not shooting the line that accelerates the loops transition, and it sounds like this may be considered tension.

I understand the definition of counter-flex & rebound, and how both pull against the line to some degree; and maybe this is now also considered tension.

In shooting line, there is some degree of resistance due to friction and redirection that may decrease the efficiency of the 'shoot', and now this is being considered to be tension, possibly.

No. You are throwing a mass of line. After Rebound, the rod forgets everything about the weight it just cast. The unfurling of the loop does not effect the speed of the shoot as much as the increase of mass that occurs by virtue of the rod leg becoming greater over time, and this having direction (SLP) gives the line pull or shoot momuntum, not the momentum of the loop in transition.

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Well, I look at tension as the result of the application of force between two connected masses moving at differing rates or between one mass which is moving and another which is stationary.

Websters dictionary definition is: 1. The act of stretching or straining. 2. The state of being stretched or strained.

Mech: a. The longitudinal deformation of an elastic body that results in its elongation.

Perhaps, then, one might deduce the amount of tension by measuring the deformation or change in length of the slightly stretched fly line legs during loop travel. I'm sure nobody has done that or actually measured the involved forces. I remember, years ago, somebody making videos of zebra striped black and white fly lines during a cast . Perhaps the change in the dimensions of the stripes would give us some information as to stretch produced by tension (?????)

I think you may be correct in that it is more accurate to look at the momentum of the rod leg which is increasing as the loop unfurls yielding tension which pulls the line out of the rod guides & tip top as line is shot.

Tension can exist between the rod tip and the fly line in different directions, too ...... I think it exists briefly in small increments as counterflex and rebound slightly deform the rod leg acting almost perpendicular to the tension between the rod leg and the rod tip.

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Seems to me it is easy to determine if there is tension on the rod leg without cutting up our fly lines,

Make a forward cast and release the line at whatever point during the cast you are interested in ( early …late etc.).

I would submit the line would shoot, admittedly with less and less energy as the cast fades( energy dissipated) but it would shoot!

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