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## Covered topics /how it works

Moderator: Torsten

Lasse Karlsson
Posts: 4577
Joined: Wed Jan 09, 2013 9:40 pm
Location: There, and back again
Contact:

### Re: Covered topics /how it works

Hi James

Aren't all models flawed, but some are useful?

Still having a hard time getting my dumb head around this, so if I next week when I get gome, take the 9 wt dt and 4 wt dt out inro the field, false cast 70 feet of each out the tip of the rod, then chop chop bot at 35 feet back from the tip, join the fat end of each (where my scissors met the lines) with a smooth connection (I would probably go with one of these
http://www.sexyloops.com/articles/smoot ... ions.shtml

http://www.sexyloops.com/articles/smoot ... ited.shtml
)

Then I will have a hard time arielising that 70 feet head?
Apart from that sounds a bit like a rio single hand spey line, I can't see why it should be really hard, but I might miss something and would be happy to give it a go if I understand correctly

Cheers
Lasse

It makes no difference at all whether you are in a fishing environment or on a casting court. Technique transcends all casting environments, irrespective of what, and where, those environments exist.

John Waters

James9118
Posts: 1386
Joined: Thu Jan 10, 2013 6:59 pm
Location: N.Wales

### Re: Covered topics /how it works

Yup, as long as the #9 (or the heavier of the two) is at the front i.e. nearest the leader.

I'd be really interested to see how you get on.

Cheers, James.

Graeme H
Posts: 2051
Joined: Fri Jan 25, 2013 2:54 pm
Location: Perth, Western Australia

### Re: Covered topics /how it works

James9118 wrote:
Sun Aug 16, 2020 6:51 pm
To my mind the current models do not predict this effect (unless I've missed something), as such perhaps the models are missing something fundamental.

Cheers, James
Transverse waves.
FFi CCI

nicholasfmoore
Posts: 408
Joined: Tue Jul 16, 2019 1:41 pm

### Re: Covered topics /how it works

Hi Paul,

What's an anchor? A portion of the fly line and/or the leader on the water.

Purpose of the Anchor in roll/speys;

Stops the fly going into trees/bushes, sheep etc behind you by 'anchoring' the tip of the fly line on the water.

It enables you to get all the momentum going in the correct direction (forward cast)

A sliding anchor is inefficient, as the tip gathers too much momentum away from the intended target. When you start going on the forward cast, some energy goes into enabling the tip to move away from the target.

All the best
Nick M

"Memento Piscantur Saepe"

flyfisher666
Posts: 93
Joined: Wed Jan 09, 2013 10:09 pm
Location: Ryd, Sweden

### Re: Covered topics /how it works

Q: How does a loop morph?
A: From big to smaller.

Q: Why does a loop morph?
A: As the loop propagates away from you the tension force acting on the rod leg part of the loop gets more parallell with the fly leg and therefor "pull" the loop tighter.

gordonjudd
Posts: 1448
Joined: Sat Jan 19, 2013 11:36 pm
Location: Southern California

### Re: Covered topics /how it works

To my mind the current models do not predict this effect (unless I've missed something), as such perhaps the models are missing something fundamental.
James,
I expect that Gatti-Bono's equations governing the dynamics of loop generation are quite complete. The problem is they are so complicated (six equations six unknowns that earned her a PhD while developing a technique to solve them) that no one on this forum is going to be able to apply them.

Something more basic to the propagation of a loop in your reversed line set up has to do with the lower tension (positive acceleration force) provided by the rho_l*v_tangential$$^2$$ of the #5 line trying to overcome the larger drag forces and mass of the #7 line behind it.

Gordy

flyfisher666
Posts: 93
Joined: Wed Jan 09, 2013 10:09 pm
Location: Ryd, Sweden

### Re: Covered topics /how it works

James9118 wrote:
Sun Aug 16, 2020 9:08 am
Hi Lasse,

For me yes, it became pretty ugly - a bit like a casting a WF with an abrupt rear taper with too much overhang.

Cheers, James
It's more or less what it is isn't? A wf with no backtaper and a really thick running line. Did you try it the other way around? The #5 closest to the leader?

//Joakim

James9118
Posts: 1386
Joined: Thu Jan 10, 2013 6:59 pm
Location: N.Wales

### Re: Covered topics /how it works

As I've said many times the Gatti-Bono paper is one of the typical unvalidated piles of cack that gets reeled out time and again as being the final word on fly casting. It's not, I doubt she can fly cast to save her life - if she could, she would have got out there and done some actual validation. Incidentally, she ended up working in one of the US labs that is equivalent to the one where I work, I hope she does a better job there than on her fly casting paper. I can't see why solving the differential equations in the paper would merit a PhD, but then again they give them out like bog roll in the US.

My test isn't a 'reversed line set up', it's a bog standard WF with no rear taper. Your statement implies that the #5 is somehow towing the the heavier line - this is nonsense. You haven't asked any questions at all about why my casts failed because you're not interested, you just want to make it fit with your confirmation bias.

James.

gordonjudd
Posts: 1448
Joined: Sat Jan 19, 2013 11:36 pm
Location: Southern California

### Re: Covered topics /how it works

You haven't asked any questions at all about why my casts failed because you're not interested, you just want to make it fit with your confirmation bias.
James,
To the contrary, I would like to see your videos that show the details of why your casts failed.

I was just pointing out that it is easier for heavy section of line to tow a lighter one, rather than the other way around. If that does not make sense to you I would like to lhear about how you see the problem. Videos and data to validate those views are most welcome.
Gordy

Bianchetti Ivan
Posts: 186
Joined: Wed Sep 30, 2015 8:25 am

### Re: Covered topics /how it works

Excuse my ignorance, while the line is in flight the front slows down more than the back, if the tension serves to remove the part that slows down, the rest will probably keep its position and speed?