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### Fly rod deflection

Posted: Sat Aug 20, 2016 9:52 pm
Has anyone read or watched the video explanation of the above by Tobias Hinzmann all about fly rod deflection? My questions are: Do you agree with his findings? How can understanding this information help me become a better fly caster and last could some one explain his findings in the simplest lay term ways http://www.passionfliegenfischen.de/exp ... eflection/ I sorry you have to recapture the link Thanks in advance slack

### Fly rod deflection

Posted: Sun Aug 21, 2016 12:33 am
if that's what you are talkiing about. I can't watch vimeo for some reason unless they are imbeded.

I don't understand what the point is of what he is saying.

It seems to me that he is saying that a rod which is straight at the beginning of a casting stroke starts bending with the center of the grip on the rod being on the diameter of a large circle. As the cast progresses the diameter of the circle roughly described by the rod bend rises up the rod towards the direction of the fly leg and its diameter decreases as this is happening. The center of the shrinking circle follows, generally, the trajectory of the cast.

I have no idea how this would help anyone's casting or to understand better what they should be doing to make this occur in the most effective way.

Perhaps someone else can explain it to us both.

### Fly rod deflection

Posted: Sun Aug 21, 2016 1:32 am
Thank you WJC. Lets hope someone picks this up and can watch the video and explain the merits of understanding it and can explain in simple language the benefits of knowing and using this information and if they agree with his findings. To future participant's thanks in advance. slack

### Fly rod deflection

Posted: Sun Aug 21, 2016 3:01 am
I think I understand the points Tobias is making but I can't put them into simple terms and I certainly can't find a way to make the ideas into something that will help me (and my students) cast more effectively. I can't find a way to relate upwardly progressing and diminishing circles to a person's casting faults.

Cheers,
Graeme

(BTW, I disagree that the circle disappears as the rod straightens. The circle is transferred to the line and becomes the centre of rotation of the loop. The tighter that "centre of rotation circle" on the rod becomes, the tighter the loop is.)

### Fly rod deflection

Posted: Mon Aug 22, 2016 3:10 pm
To me it looks like there first was an observation which actually seems to be there which then lead to a theory which is not there. If rod has a full action this circle size change ends bigger.

Esa

### Fly rod deflection

Posted: Mon Aug 22, 2016 4:05 pm
Tobias, Franz Joseph and I met in Berlin about one year ago to discuss our views. To me their approach looks like the inertial effect, viewed from a different angle. Maybe there is a mix with the harmonic oscillator mechanism too. I hope they can succeed in having a specific study made with a graduate of their University, this was their intention at least. For the time being, I still have difficulties with this approach, I hope I can see some theory / equations / principles written sometimes, that will help to catch their point. As it is, it appears quite subjective to be easy to understand for laymen, whislt it could carry some interesting concepts.

Never underestimate the value of the unexpected.

Merlin

### Fly rod deflection

Posted: Tue Aug 23, 2016 8:34 pm
Thanks all who tried to help me understand the video. slack

### Fly rod deflection

Posted: Wed Aug 24, 2016 9:46 am
Have you seen the video which comes next on Youtube? It is another one from Tobias, and it may help you to see what is meant. If I caricaturize the approach, it would be possible to transfer all the kinetic energy travelling through the rod to the line. In that case there would be no counterflex. The remaining energy in the rod at the end of the cast would then be negligible, but this means that the equivalent mass of the rod would be negligible, or that the tip speed would come to zero at RSP, or both. In such a case, the max line speed must have occured well before RSP. To me this does not correspond to what takes place, but maybe the potential study from the Berlin University will allow clarifying that point.

Merlin

### Fly rod deflection

Posted: Wed Aug 24, 2016 2:26 pm
Here is the link to that second video

Merlin

### Fly rod deflection

Posted: Wed Aug 24, 2016 2:36 pm
I think there are a number of implications.

One is that effective rod length is not just the distance from the handle to the rod tip since the center of rotation moves. This would also mean that the fulcrum point moves if you want to consider lever action. It also affects our understanding of how to achieve slp and why large casting arcs are reasonably efficient for distance casting.

Another has to do with measuring the moment of inertia of the rod because the center of gravity moves throughout the cast.

It could also affect the choice of rod actions - full flex vs tip flex.

There are other stuff as well but it requires more time to think about and put into words than I have available.

It is an interesting video. Thanks for pointing it out.