Understanding Fly Lines

ohanzee

Well-known member
Joined
May 7, 2010
Messages
41,429
Well, from learning to fish with that "junk" to fishing with some of today's rubbish has to be a marked improvement. There's still the subject of understanding fly lines to resolve... :cautious:

Sakes, ok, I will be objective on the subject :p
 

ohanzee

Well-known member
Joined
May 7, 2010
Messages
41,429
I object to that..subjectively..

Not actually sure where you go with this next, I think if Tangled can link profile to function clearly the job is pretty much done, maybe just thrash out the bits that don't look right or...take it to the next level....what is the next level?:unsure:
 

James9118

Well-known member
Joined
May 26, 2009
Messages
2,198
Location
Hampshire
Could it be be that I'm asking - quite unreasonably - for proof beyond subjective opinion and hearsay? I'm prepared to accept the received wisdom of the experts but objective proof would be great too and find it odd that it hasn't been produced.
Ok, let's start with distance - do you accept the results from the last few years of #5 distance casting competitions that indicate the winner has used one of only two lines as objective proof that those particular tapers are the best for distance?
 

tangled

Well-known member
Joined
Dec 28, 2015
Messages
5,024
Ok, let's start with distance - do you accept the results from the last few years of #5 distance casting competitions that indicate the winner has used one of only two lines as objective proof that those particular tapers are the best for distance?

Well, not knowing anything at all about those competitions, I'd say that those results could provide a good hypothesis for proper testing. It really depends on how the thing is structured. Do you have some data? Or is there a website that shows the various results?
 

James9118

Well-known member
Joined
May 26, 2009
Messages
2,198
Location
Hampshire
There is a website with the results, unfortunately it doesn't list the fly line used. However, I personally know every winner and know what tackle they used.

The structure is that you turn up with any 9ft #5 outfit (with a line that conforms to the AFFTA spec) and you have a set time to cast as far as possible. I couldn't tell you what all the competitors use, but I know for certain what the winners did. Quite telling that over the years I looked (I could have gone back further) only two lines have been used to win.

Next question, have you looked up the scientific papers (all peer reviewed and printed in respected scientific journals) on why whips 'crack' and the role the taper has in making this happen?
 

original cormorant

Well-known member
Joined
Jul 3, 2016
Messages
1,200
There is a website with the results, unfortunately it doesn't list the fly line used. However, I personally know every winner and know what tackle they used.

The structure is that you turn up with any 9ft #5 outfit (with a line that conforms to the AFFTA spec) and you have a set time to cast as far as possible. I couldn't tell you what all the competitors use, but I know for certain what the winners did. Quite telling that over the years I looked (I could have gone back further) only two lines have been used to win.
Yeah but it's a self selecting sample, how many turn up without MED or GT?

However that does mean that the most competent casters have selected these lines.
 

shortcircuit

Well-known member
Joined
Apr 18, 2016
Messages
212
Guys, a bit of a TL-DR here, I haven't gone through the pages of debate about profiles etc.

I just want to say thank you to Tangled for his original post. It is really well written and makes great sense from my point of view. I wish it had existed five years ago when I started out!
 

James9118

Well-known member
Joined
May 26, 2009
Messages
2,198
Location
Hampshire
Yeah but it's a self selecting sample, how many turn up without MED or GT?

However that does mean that the most competent casters have selected these lines.
I'd say the majority use different lines. However, on any given day you know who the contenders for winning are - and this group are likely to be using certain lines that maximise distance for them.
 

tangled

Well-known member
Joined
Dec 28, 2015
Messages
5,024
There is a website with the results, unfortunately it doesn't list the fly line used. However, I personally know every winner and know what tackle they used.

Can't do anything without data. But if you know what line profiles were and the rods used and the results then you have a start.

The structure is that you turn up with any 9ft #5 outfit (with a line that conforms to the AFFTA spec) and you have a set time to cast as far as possible. I couldn't tell you what all the competitors use, but I know for certain what the winners did. Quite telling that over the years I looked (I could have gone back further) only two lines have been used to win.

It would be interesting to see that in a useful form.

Next question, have you looked up the scientific papers (all peer reviewed and printed in respected scientific journals) on why whips 'crack' and the role the taper has in making this happen?

I have read a couple yes, but if you have a list, I'd be interested. I'm not a physicist but I'm very used to reading scientific papers
 

tangled

Well-known member
Joined
Dec 28, 2015
Messages
5,024
Some light reading (a couple of the diagrams may look very familiar...).
I believe that the current thinking is that it is the loop of the whip that creates the sonic boom not the tip but it still explains it well.


Ok thanks, that's straightforward enough - in that it explains line acceleration - but it doesn't deal with tapers, which is what we're interested in (it assumes a level line). The maths will get considerably more difficult with compound tapers.

Of course it follows that as a line reduces in mass as it extends, line speed must increase (assuming constant energy input) and we use this feature in tapered leaders and the front of a fly line (to varying extents) to turnover our fly.

But a key design feature of fly lines is that they are actually not designed like whips. Whips use a continuously thinning taper

1606919796513.png
while our fly lines start thin, increase in thickness, flatten out (usually) then decrease in thickness.

1606919838716.png
(I just happened to be looking at the MED line, comparing it to the Ballistic)

So, following the logic, that line would slow down along the majority of its length until it hits the forward taper, then, so long as it's got any energy left it's going to flick over the thinner section. All suggesting that you have to put a hellovalot of energy into it to keep it in the air.
 
Top