Fishing The Fly Scotland Forum

Ben Dixon

Robs line weight question
« on: 19/02/2013 at 18:56 »
Hi Ben,
Not sure I grasp what you mean regarding being shorter thus lighter

Take a 5wt trout line for example, approx 140 grains at 30' to "load" most #5 rated rods. Think about a SA ED line (head 67'4" in a #5) the weight of the head is 276 grains and it feels right on most rods rated #5 when all of it is being cast.  Condense that 276 grains into 30' and it would feel very heavy indeed, likewise, stretching 140 grains over 67'4" would feel very light.  Does that make sense?

Cheers

Ben

Rob Brownfield

Robs line weight question
« Reply #1 on: 20/02/2013 at 09:40 »
Take a 5wt trout line for example, approx 140 grains at 30' to "load" most #5 rated rods. Think about a SA ED line (head 67'4" in a #5) the weight of the head is 276 grains and it feels right on most rods rated #5 when all of it is being cast.  Condense that 276 grains into 30' and it would feel very heavy indeed, likewise, stretching 140 grains over 67'4" would feel very light.  Does that make sense?

No, because what you have just told me is that 1 ton of lead weighs more than 1 ton of feathers  ??? unless you are talking about spey casting, then it makes sense because I realise its all about the belly giving the weight, and a shorter line would concentrate the weight more.

If you aerialise (because you talk about the SA line I presume you are) 140 grains at X feet and 276 grains at Y feet, you are still loading the road with the respective weights. Just coz its longer cannot mean it is lighter, it weighs what it weighs if flying through the air.

Ben Dixon

Robs line weight question
« Reply #2 on: 20/02/2013 at 11:17 »
No, because what you have just told me is that 1 ton of lead weighs more than 1 ton of feathers  ??? unless you are talking about spey casting, then it makes sense because I realise its all about the belly giving the weight, and a shorter line would concentrate the weight more.

If you aerialise (because you talk about the SA line I presume you are) 140 grains at X feet and 276 grains at Y feet, you are still loading the road with the respective weights. Just coz its longer cannot mean it is lighter, it weighs what it weighs if flying through the air.

Ton of feathers weighs no lessthan a ton of bricks Rob.  Not got time to re-explain this just now mate, thought I was clear first time around, will come back to it later  ZX2  :z4

See Rio's lines on their website, the THE TOTAL WEIGHT OF OF THE HEADOF A LONG BELLY WILL BE MORE THAN THE TOTAL WEIGHT OF HEAD FOR A SHORT BELLY THAT WILL WORK THE SAME ROD!  Think about it Rob.......

Cheers
Ben

Rob Brownfield

Robs line weight question
« Reply #3 on: 20/02/2013 at 12:42 »
Ton of feathers weighs no lessthan a ton of bricks Rob. 


Thats my point. Just because something is bigger in volume does not mean it is bigger in weight and visa versa..

Anyway, I will try the line..if its too heavy, its too heavy.

Ben Dixon

Robs line weight question
« Reply #4 on: 20/02/2013 at 12:58 »


Thats my point. Just because something is bigger in volume does not mean it is bigger in weight and vice versa..

Anyway, I will try the line..if its too heavy, its too heavy.

If that really is your point Rob, I'm very worried ZX2
We are not talking about densities here. it is the weight of line relative to the length

Again, in case I was not clear enough second time around I'll use DH lines, you may find the comparison easier to grasp. 

Go look up weights for Rio Power Spey in a 10/11, then do the same for the Uni Spey and AFS in the same size.  In the order I listed them, you will see a decrease in head weight as the length decreases, they all still work a 10/11 rod at the lengths they are designed to be cast.

From memory a power Spey 10/11 weighs 825 grains at 71', a 10/11 AFS weighs 640 grains.  If you stick a 640 grain (8/9) power Spey on your 10/11 rod, it will feel far too light likewise, if you stick a 10/11 (640 grain)AFS on your 8/9 rated rod it will feel too heavy.

If this still makes no sense, get Cas to read the whole thread and maybe she'll explain it to you   :z4


Cheers

Ben

Iain Cameron

Robs line weight question
« Reply #5 on: 20/02/2013 at 13:03 »

... most of the rods in the UK at least were being used as short two handed rods by anglers chasing salmon or sea trout on smaller rivers or on the larger rivers in low water conditions therefore, it makes sense to line them for that purpose.  The aim was to produce a line that would cast well two handed on 10'6" - 11' 6" rods and allow delicate presentations on long tapered leaders with small flies, also lump gear about, cast well over a range of distances and, be manageable on that length of rod for Spey casting in confined spaces.  ....
....

Really looking forward to this hitting the market, anyone want to buy a Beulah Elixir from me?

Will you give me a refund on the Beulah Elixir you flogged me first... :-)
(It's a very nice line, I've been happy with it, so if the Barrio Switch improves on it, then that'll be great)

Nice post Ben - very informative, and sounds like you & Mike have been very clear about the objective - a line for light double-handed work. Grand.

cheers
iain

Loxiafan

Robs line weight question
« Reply #6 on: 20/02/2013 at 13:17 »
Jeez I'm glad I fish for trout, my heid is hurting wi a' this grains, grams, heids, belly's  :z4

Ben, when you told me the GT90 was a "light line", is this in reference to the point you are making here - if so, even I can understand it.....just !  :z4

L

Ben Dixon

Robs line weight question
« Reply #7 on: 20/02/2013 at 13:42 »
Hi Linsday,

The total weight of the head on the GT90 #5 will be greater than the total head weight of the SLX #5 but, over the first 33', the SLX #5 will weigh more than the GT90 #5.  That is probably what I was getting at when I told you the GT90 was a light line.  The GT90 is a true to standard AFTMA #5 line and as such weighs approx 140 grains over the first 30'.  Does that answer your question?

Cheers

Ben

Iain Cameron

Robs line weight question
« Reply #8 on: 20/02/2013 at 13:47 »
using my lunchtime to do some brain training...

I think (??) it boils down to comparing the grain weight per foot (which gives a common measure, getting away from the concern about comparing elephants and shoelaces...)

Rio chart at http://www.rioproducts.com/skin/summit/pdf/Spey%20Weight%20Chart%202013.pdf

For 10/11 rated lines:
Powerspey: 850 grains, 71 foot head - average grains per feet is 11.9
uni spey: 750 grains, 64 foot head - average grains per foot is 11.7
AFS: 640 grains, 40 foot, 16 - average grains per foot is 16

(average grain weight per foot ignores the obvious differences caused by tapers etc)

So yes, the overall head weight decreases (850, 750, 640) for shorter heads but the average weight per foot (11.9, 11.7, 16) rises. Science fact!

I guess this is where the confusion arises (head gets lighter overall, but each foot of the head is heavier)

i'm getting back to work now...
iain


Loxiafan

Robs line weight question
« Reply #9 on: 20/02/2013 at 14:17 »
Hi Ben,

Thanks for that reply, that was exactly my understanding about the GT90 being a 'light' line !  :z16

Cheers,

Lindsay

Rob Brownfield

Robs line weight question
« Reply #10 on: 20/02/2013 at 14:51 »
using my lunchtime to do some brain training...

I think (??) it boils down to comparing the grain weight per foot (which gives a common measure, getting away from the concern about comparing elephants and shoelaces...)

Rio chart at http://www.rioproducts.com/skin/summit/pdf/Spey%20Weight%20Chart%202013.pdf

For 10/11 rated lines:
Powerspey: 850 grains, 71 foot head - average grains per feet is 11.9
uni spey: 750 grains, 64 foot head - average grains per foot is 11.7
AFS: 640 grains, 40 foot, 16 - average grains per foot is 16

(average grain weight per foot ignores the obvious differences caused by tapers etc)

So yes, the overall head weight decreases (850, 750, 640) for shorter heads but the average weight per foot (11.9, 11.7, 16) rises. Science fact!

I guess this is where the confusion arises (head gets lighter overall, but each foot of the head is heavier)

i'm getting back to work now...
iain



Totally get that for DH, but not overhead as used in the first explaination.

Ben Dixon

Robs line weight question
« Reply #11 on: 20/02/2013 at 15:06 »
Totally get that for DH, but not overhead as used in the first explaination.

So this would differ when casting overhead would it?  It applies for all lines Rob, why wouldn't it?


Rob Brownfield

Robs line weight question
« Reply #12 on: 20/02/2013 at 15:23 »
So this would differ when casting overhead would it?  It applies for all lines Rob, why wouldn't it?

Ok, because I am presuming that to cast, the whole head needs to be out the tip ring...so a longer, heavier head will load a rod more than a shorter, lighter line, when all the head is out, because it is in the air, not laying on the water.

If you are talking about only the first 30 feet, then yes, I can see how it would work.

Ben Dixon

Robs line weight question
« Reply #13 on: 20/02/2013 at 15:37 »
Ok, because I am presuming that to cast, the whole head needs to be out the tip ring...so a longer, heavier head will load a rod more than a shorter, lighter line, when all the head is out, because it is in the air, not laying on the water.

If you are talking about only the first 30 feet, then yes, I can see how it would work.

Dude,

If you are serious about trying to understand it, go start a new thread in the casting section and I'll try to help you out with it tonight when I get home.  We're just jamming up the switch thread here!!

Ben

Hamish Young

Re: Robs line weight question
« Reply #14 on: 20/02/2013 at 17:49 »
Your wish is my command - new thread created  :cool:

Irvine Ross

Re: Robs line weight question
« Reply #15 on: 20/02/2013 at 19:16 »

See Rio's lines on their website, the THE TOTAL WEIGHT OF OF THE HEADOF A LONG BELLY WILL BE MORE THAN THE TOTAL WEIGHT OF HEAD FOR A SHORT BELLY THAT WILL WORK THE SAME ROD!  Think about it Rob.......

Cheers
Ben

Ben

I don't get this either. Tell me where I am wrong.

A rod rated for a #10 line is designed to feel loaded with 30' of "standard" fly line outside the rod tip when overhead casting. However when you are Spey casting and form a D loop, half the weight of the head is lying on the water so it is only the half of the head nearer the running line that is loading the rod. Therefore a 60' Spey head could be double the weight of the "standard" 30' head and the rod will still be loaded as we are only casting half the head. I'm ignoring compound tapers hear for the sake of simplicity.

So, with a Powerspey with the whole head out we are effectively casting 425 grains (half of the full head weight of 850) and the rod feels loaded. With an AFS with the whole head out we are effectively casting 320 grains (half of the full head weight of 640). This is only 75% of the weight of the Powerspey so how can the rod feel equally loaded?

The only explanation I can figure out for myself is that the tapers are radically different and the AFS has 425 grains in the lower part of the head and only 215 grains in the first half of the head.

 :z8

Irvine

Loxiafan

Re: Robs line weight question
« Reply #16 on: 20/02/2013 at 20:36 »
However when you are Spey casting and form a D loop, half the weight of the head is lying on the water so it is only the half of the head nearer the running line that is loading the rod.

My knowledge of casting is mince so forgive me if I am way off but is the "pick up" from the water not the first loading move on the rod tip, therefore the weight of the anchored line and it's relative drag on the water that would still have a loading effect ?

All very interesting so looking to be enlightened !

Lindsay

Ben Dixon

Re: Robs line weight question
« Reply #17 on: 20/02/2013 at 22:49 »
Ok, because I am presuming that to cast, the whole head needs to be out the tip ring...so a longer, heavier head will load a rod more than a shorter, lighter line, when all the head is out, because it is in the air, not laying on the water.

If you are talking about only the first 30 feet, then yes, I can see how it would work.

Hi Rob,

The AFTMA number refers only to the first 30' of a line and gives no description of what happens after that point.  We will have to accept here that there is no rod rating system, rod manufacturers will make a rod and it will be assigned a line rating based upon what they think it casts well for the application in which they intend it to be used. 

Forget Spey casts for a minute and think about a DT7 single handed line and overhead cast where the length of line concerned is aerialised and straightened out behind the rod as it would be if we had just made a back cast, we are not shooting line to reach our target or hauling.

So, we have 30' of DT7 line weighing 185 grains in the air behind the rod which we will deliver to our target say a trout on a still water.  Fish doesn't take the fly, it has moved 10' further out, this time we aerialise 40' of line.  The total weight of line in the air has increased, it has to as we have increased the length of line. Does it still work your #7 rated rod that casts nicely with exactly 185 grains at 30'?  I'd expect so.  The rod will bend a little more as we're accelerating it against a little more mass but that's fine, we just increase the stroke length and arc a bit during the cast.

What would happen if we decided that the rod needed 185 grains period and would not cast anything else but we still needed to aerialise 40' of line? To accomplish this we would have to put on a DT5.  Fish has moved another 10' from us so we'd need to put on approx DT3.5 to be casting approx 185 grains.  185 grains stretched over 50' is going to feel very very light, it will feel a lot lighter than 185 grains at 30' and we are going to have to move the rod very quickly to get the same bend in the rod.
If we were consistently fishing with 50' out of the tip we may go down a line size to a DT6 but 50' of line weighing 185 grains

Then look at it the other way, we aerialise 10' of line that weighs 185 grains, that's about a 15wt line.  How do you think that would feel as we increased it at 10' increments longer than that?  Again, if consistently fishing at less than 30' we could possibly go up a line size or two but we would not always want to keep the mass of line to 185 grains regardless of length.

Does that make more sense?

Cheers

Ben






Rob Brownfield

Re: Robs line weight question
« Reply #18 on: 21/02/2013 at 08:57 »
Hi Ben,
Many thanks for the reply.

I think we are now talking about two different things  :z4.

The question came about because you stated that the Elixor was a shorter line than the Barrio Switch, and therefore lighter. I can understand that after your first ecplaination, but then somehow we got onto OH casting and it appeared you were suggesting that the same principle applied as you started to talk about the SA line and head length etc. Perhaps I picked that up wrong?

I fully understand your latest post, those principles have never been in doubt in my mind and I have used lighter DT lines on heavier rods in the past to get extra distance. (Before WF lines were that popular or indeed really understood..lol)

Anyway, useful information for everyone, many thanks.


Ben Dixon

Re: Robs line weight question
« Reply #19 on: 21/02/2013 at 09:51 »
Hi Rob,

What I hoped you'd get from the above is that for a given rod, a longer line for that rod needs to have more weight to feel "right" when casting (to a point) than a medium length of line on the same rod or a short line on the same rod.  Therefore, it should follow that, in the case of WF lines (or shooting heads) where we are casting generally the whole head, that a short head for a given rod must weigh less than a long head for the same rod.  This explains the difference in weights between the Elixir and the Barrio switch lines.

Whether we are talking about Spey casting here is really irrelevant.  We are still casting a length of line with a flexible lever, the same principles generally hold for Spey or overhead casts, it's just easier to visualise a straght length of line behind the tip rather than a D loop.  How much mass is effectively levered by the rod during the stroke will change slightly for a Spey cast but that is really a different topic.

Cheers

Ben

Marc Fauvet

Re: Robs line weight question
« Reply #20 on: 21/02/2013 at 13:38 »


Whether we are talking about Spey casting here is really irrelevant.  We are still casting a length of line with a flexible lever, the same principles generally hold for Spey or overhead casts, it's just easier to visualise a straght length of line behind the tip rather than a D loop. 

 :z16

Marc Fauvet

Re: Robs line weight question
« Reply #21 on: 21/02/2013 at 13:51 »
My knowledge of casting is mince so forgive me if I am way off but is the "pick up" from the water not the first loading move on the rod tip, therefore the weight of the anchored line and it's relative drag on the water that would still have a loading effect ?

Lindsay

hey Lindsay,
that's a very common misconception (but don't worry, it's the kind of thing that's repeated ad nauseum all over the place even though it's false)

A to B, (the D loop) is the weight we are applying force against (combined with the caster's movement and rod weight)  to bend/load the rod for the forward roll. we don't load against the anchor, it's just there to keep the line tip/leader to swing backwards during the forward stroke.
the best and most simple test to have a once and for all confirmed view of this is to do a roll cast on a smooth dry surface. there  is no real anchor because there isn't water tension to hold the line but the rod is perfectly loaded and the cast still works. (it's not ideal but it's to prove a point)
watch this :)
http://vimeo.com/aitorc/anchor-and-loading
cheers,
marc

Loxiafan

Re: Robs line weight question
« Reply #22 on: 21/02/2013 at 14:45 »
Thanks Marc, totally get it there with a Spey/Roll, but that wouldn't be the case in a conventional 'pick-up' where we are actually plucking/lifting the leader and line from the water as in a side or overhead cast would it ? Or would it !  :oops

Cheers,

Lindsay

Marc Fauvet

Re: Robs line weight question
« Reply #23 on: 21/02/2013 at 15:15 »
Thanks Marc, totally get it there with a Spey/Roll, but that wouldn't be the case in a conventional 'pick-up' where we are actually plucking/lifting the leader and line from the water as in a side or overhead cast would it ? Or would it !  :oops

Cheers,

Lindsay

hi Lindsay,
that's the 'lift', this is how a lot of us like to consider this part.
from the SexyLoops Fly Casting Model - Core definitions http://www.sexyloops.com/flycasting/definitions2.shtml

Lift: An upward Sweep.
The primary purpose of Lift is to begin to clear line from the water prior to a further line positioning movement or Casting Stroke.


as such, it's not included in the casting stroke (or what some refer to as 'the loading move')
sure, the rod is bending but only a little. definitely not what we can consider 'loaded' and definitely not enough to cast the line past the rod tip and form a loop.

have a good look at the link above and don't hesitate if some things aren't clear.
hope this helps,
marc

Ben Dixon

Re: Robs line weight question
« Reply #24 on: 21/02/2013 at 15:28 »
Hi Marc,

IMO, the diagram you posted only really holds for short heads and even then I'm dubious about the position of point B.  If you look at high speed stills of a Spey with a long belly, the rod has often hit RSP1 (straightened at the end of the forward cast) and the leader has not moved.  I would say point B is, in many cases, closer to the apex of the D loop although I am fully prepared to be convinced otherwise.

Agree 100% about the anchor, it is simply there to provide tension and hold the front end of the line in place until it is picked up by the back end of the head and carried into the top leg of the forward loop.
Having no anchor is in effect just like making an over head forward cast before the back cast has fully straightend.

Cheers

Ben

 




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