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Grain Window confusion

10K views 21 replies 14 participants last post by  surfdog 
#1 ·
I have only been Spey casting coupe of years and after reading several posts on how to properly use the grain window I am confused as I found several opinions on the topic that are 180 degrees apart.

So here goes, the question is simple: Do you add the weight of the sink tip to the weight of the skagit head when trying to stay inside the window.

Here is the confusion. I always thought and have read here on Spey pages you do not include the grain weight of the sink tip since it does not form part of the D loop. But when I read the following from RB Meiser’s website explaining the grain window he wrote the following: “The high end of the grain window for this rod is 600 to 800 + during sustained anchor line management typical of Skagit style shooting heads with extreme sink tips in tow. The grain total managed here would be the combination of head and tip weight. A Skagit shooting head of 600 grain with 200 grains of T-14 in tow would net 800 grains... This would meet the high end of the grain window- grains, and would define the maximum amount of grains that the rod will allow the blank to load efficiently.”

It’s obvious I am missing some. Thanks in advance
 
#2 ·
I'm no deep thinker, and my mind has trouble wrapping itself around certain theories and philosophies, but my take to figuring out lines, heads, tips, leaders, fly weight etc it this - if it works, who cares what the numbers are?

Grain windows are just suggestions for a place to start. There is no right or wrong. Just like recipes, they're just suggestions that someone else came up with. If you don't want to add something to a dish, then for Pete's sake, leave it out, or replace it with something else. If your line casts well, and you're pleased with the way it presents your offering, then who cares what the numbers say.

Go fishing, and enjoy your time on the water! :wink2:
 
#4 ·
I believe that grain window expresses the minimum and maximum weights that should be used with a particular rod. A rod needs a certain amount of line weight to be flexed and loaded properly. The maximum side of the window refers to the most line (and tip, and fly) that can be cast without dangerously stressing the rod (which is a hollow tube of somewhat brittle material, expected to endure thousands of casts during its working life).


Taking the above example, as one goes through the steps of a spey cast, the combined load first has to be moved from the dangle to a proper anchor point (one stress episode), then redirected to make a backcast, then launch the load forward. At the beginning of the D loop backstroke, as the sink tip puddles near the surface, it and the fly aren't adding to the load. But when the cast is stroked forward, all the parts are again loading the rod. So it's best that the line combination not exceed the 800 grain maximum specified by the grain window, if one wants the rod to endure into future generations.

So, an accurately reported grain window is very useful information.
 
#6 ·
You should be careful approaching casting thinking rod "load". Fly line is accelerated and when rod bends it makes us possible to widen casting stroke and it has positive effect to line speed without line loop widening. Too much rod bend for used casting stroke usually results a Tailing Loop.

Fly line casting is always a compromise and for Spey casting biggest compromise comes from the water anchor because it waste energy and to compensate we need to use more force.

Overhead cast has highest efficiency and Sustained Anchor cast lowest but line has effect to Spey cast efficiency. Typical Skagit line which tip sinks fast incease water drag and short leader and proportionally heavy line tip increase weight in bottom of the D-loop and it is what the top of the D-loop needs to pull out of water and accelerate to line loop.

Typical Scandi line when Spey casting is somewhere between OH cast and SA casting Skagit line.

When same weight and length Skagit and Scandi heads are cast overhead Scandi is bit easier to straighten smoothly and from good back false cast the delivery forward cast comes good and although the difference is small Scandi casts bit longer. When casting to strong head wind Skagit might straighten better and cast come longer than Scandi head but I have not test it properly.

When long mono leader is put to both lines and Spey cast Touch&Go and Sustained Anchor there comes very little difference but casts come shorter than Overhead.

When short mono leader is put to both the SA casts come shorter than T&G and I can think there are three reasons. Perhaps biggest effect comes is because there is less weight difference between top and bottom of the D-loop. Short leader also increase "anchor blow" which decrease efficiency. And short leader makes fly line shorter which usually shortens the cast when line loop run time comes shorter.

Esa
 
#7 ·
Ad half the weight of whatever sink tip weight is, as rule of thumb. Was taught this, Ive tried this and it seems to help me. Its a biatch for me to cast t14 with my 425 gn head. Was easier when I went down on the head size to 350. I can do it with the bigger head though its not pretty, and I tire much sooner.
 
#8 ·
You can take Bob's word for it on his rods.

I've purposely overlined and underlined his rods, and I think his recommendations are right on. It's just not efficient casting when you're too heavy or too light.
Over time I've arrived at my own preferences for lining Bob's rod's, and my window has gotten narrower because I'm looking for a specific feel- but my window's always within Bob's recs. Kind of uncanny if you ask me.

They don't call that dude Yoda for nothing!
 
#9 ·
Another thing missing in so called "window grain" is that the same lines ( for example Scandinavian heads) of the same total weight and length can be felt on the same rod somewhat differently. It is all about drain distribution. If a head A is 20-25 gr heavier in the rear 50-60%, then line B it will load a given rod deeper, but not significantly.
 
#10 · (Edited)
There are a number of posts on SP over the years that address this exact issue, so you could also check them out. Ultimately windows are just recommendations, as Bob B says above, so don’t sweat it too much. It’s not that kind of exact science. However it helps to at least understand WHAT is being recomended by the manufacturers, and the confusion might have a little to do with the fact that there are really (at least) two kinds of gain windows out there. Yep, it can be confusing when you first start out.

The main kind in terms of numbers - If you see a grain window that has a range of 100 grains plus/minus a bit that is a grain window that is meant to indicate the weight of the HEADS you use, and the range is meant to encompass what weight range heads are most efficiently castable with that rod. The range typically includes the range in the best weights of different types of lines, AND the natural variations individual’s have in their casting preferences. So for example the weight of a skagit head you like on a particular rod wiil typically be 40-60 grains heavier than the weight of a scandi head you like, and different people (and possibly the same person in a different mood) may have a general preference for lighter or heavier lines in general, so add another 30-40 grains. That is where the range comes from, and this type of window really doesn’t have anything to do with tips which are a whole other thing. There are tips that match the lines you choose, but the weight of the tips does NOT come into this type of grain window, which FWIW is what the vast majority of rod makers out there use. But to not understand this, as even many fly shop guys that don’t spey cast themselves sometimes do not, is a common prescription to get a crap, way too light recommendation on which head to use when sink tips are involved. We have seen this many times from stories posted on here.

Then there are the Bob-Meiser-style grain windows - you will know them by the fact that they are FAR larger - 250-350 grains wide - and possibly by the fact that it is a Meiser rod. There Seem to be far fewer companies that use this type. By all accounts Meiser invented the idea of a grain “window” for a (modern) spey rod, but if I had to guess some of the confusion out there come from his pervasive influence rather than the actual prevalence of these big windows. The big Meiser windows are the full-featured Rolls Royce version of what a grain window can be, fully thought out, and perfectly explained at the proper length on the Meiser web site. That is like a users manual for grain weight. If you haven’t read the Meiser grain window page(s), regardless of whether you own one of his rods, you are still a grain window virgin. ‘Nuff said, go do it.

https://meiserflyrods.com/spey-shop/sgs-scandi-skagit-shooting-heads/what-is-a-grain-window/

https://meiserflyrods.com/spey-shop/sgs-scandi-skagit-shooting-heads/balanced-rod-line-marriages/

There are a few clarifying caveats we could add here ...

- Everyone that does this long enough will develop their own rules of thumb (that work for them) on how to treat these windows, some examples of which have been given above. Try them or ignor them. There is nothing rigorous about any of these shorthands, but hearing them MAY help - that is, unless you are the kind of person that just gets more confused by the lack of a single standardized set of rules.

- Both Airflo and Rio have extensive line charts available online listing many, many rods and the suggested weights of their various lines for each rod. Rio even has an A and B rating - one for those who like lighter lines and one for those who like heavier. I would start there - if you can’t find your exact rod there you will find something close.

- A lot of rods just have one number and leave it up to you to have the knowledge of how to adjust for different style lines and to taste. With one number there can be no confusion about exact instructions - plausible deniability for THEM when YOU muck things up. :) The same thing could be said about the regular narrow widows - a bit of plausible deniability. With the Meiser window (plus the “manual”) all the info is there and the rest is up to your personal tastes.

- From many, many stories (there are lots on here) we know that the guy at your local fly shop it’s not to be trusted out of hand when it come to grain weight. So take those guys with a grain of salt the first time you ask a new one for info. Its not necessarily that they are just trying to sell you something no matter what, but sometimes they don’t spey cast themselves or even fully understand the systems. I imagine things are getting better over time, but if you just walk in to say a Cabelas and ask the first guy you see, and not the one guy that is sometimes there and actually know what he is talking about you are likely to get advise that is bad. If you crowdsource the answer to the question on speypages you typically get far more reliable info.
 
#12 ·
Matching the correct head and tip with a rod is really fun thing to figure out if you have the time (you will have the time). Read Meiser’s write up and apply what he says and go from there. I have found through my research that taper and length of the head count just as much as the grains that most people lose sleep over. Sometimes I need a shorter head (Commando) with a longer tip, sometimes I need a little longer head ( Skagit Compact) with a shorter heavier tip depending on what is tied to the end of the leader. To me the grains are important but length of head, taper, and tip length are also key.
 
#13 · (Edited)
Yes the main thing, if you want to know, about matching a tip is the grains/ft (linear density). That is what controls the smooth transfer of energy forward during the cast. Ideally grains per ft on the tip should be a little less but sort of close the the grains per ft the end of the line. The latter you may have to guesstimate a bit. With a skagit head you can get away with some absurdly long tips if you at least obey this rule, so if you absolutely must have more depth, and you already know the line casts perfectly with say t11, then consider going with more length - you could even connect two together. A long time ago some guys I know did an experiment and published the results where they decided that with a skagit head you could cast almost whatever weight tip (and I think to some degree head) you want, and they came up with a rough rule that you could go to 1/2 the weight of the head itself. I don’t know if they invented that rule, or (as seems far more likely) were merely confirming something that was already around back then, but a quick calculation will tend to convince you this would be a far heavier tip than you are ever likely to use. There is nothing like doing a thorough experiment.

True story, I was fishing for Shad with one of those guys (and I think the other was on the river with us as well) and I needed a lot more depth at one particular spot. All I had was another of the same tip so he convinced me I should just loop two together - so 20’ of what was essentially t8 density stuff. After making a few minor adjustments to my casts it was surprisingly easy with twice the total weight and lenght, and definitely made a tight loop.

These guys have a bunch of their stuff on the site “fly fishing research”. The info is far more that most people ever want to know about the subject, the information is organized “old school” bordering on hard to navigate, and it may be a cautionary reminder where an engineering degree and an obsession can take you. But it is an extremely cool site and there is nothing else like it.

Fly Fishing Research

The other thing a lot of people recommend for understanding this stuff, also something to maybe save for if and when you too become an obsessive, is Al Buhr’s very cool little pamphlet/book on “designing fly lines”.
 
#16 ·
I received the little book by Al Buhr from Poppy at the Red Shed and started reading it last night, very interesting.

I found this little bit of information (can’t remember from were) regarding if your skagit head will turn over T14. Take the grain weight of the head & divide the weight by the length & then multiply that result by 75%. This number is the maximum T material your skagit head can turn over. Example: Using a 420 grain head that is 24’ long, divide that by 0.75 = 13.125. So T14 would be a struggle to cast.

I am one of those guys that once he makes the decision to do something it is 100% full speed ahead. The decision to put down my single hand rod a few years ago and stick to 2 hand rods has been quite the journey. Get ready as there will be more questions coming as I dive deeper into the complexity of 2 handed rods. Full confession though, when the bead bite is on up here in Alaska, my Centerpin setup comes out and shines.
 
#17 ·
Grain window confusion

Take the grain weight of the head & divide the weight by the length & then multiply that result by 75%. This number is the maximum T material your skagit head can turn over. Example: Using a 420 grain head that is 24’ long, divide that by 0.75 = 13.125. So T14.

Do you know where the sink tip length comes in? Or does it?

Pound
 
#19 · (Edited)
Take the grain weight of the head & divide the weight by the length & then multiply that result by 75%. This number is the maximum T material your skagit head can turn over. Example: Using a 420 grain head that is 24’ long, divide that by 0.75 = 13.125. So T14.

Do you know where the sink tip length comes in? Or does it?

Pound
Interesting. Thank you for the info. What about the length of the sink tip?
 
#21 ·
Mad,
If your rod has a listed grain window and its manufacturer has described the meaning of its particular grain window methodology, such as Meiser, follow that.

For the rest of the world I have used the following since 1996, the date three of us at San Francisco's Golden Gate Angling and Casting Club published the seminal article on Skagit line casting, based on casting more than 1,000 rod/line/tip combinations.

For rods 12' and longer use standard length Skagit heads (Rio Max or Airflo Compact) or the long Skagit if you are on big rivers. Use of short Skagit heads with rods over 12' results in frequently torn out anchors.
- 6-wt rod: 450 grain Skagit
- 7-wt rod: 550-600 grain Skagit
- 7-8 wt rod: 550-600 grain Skagit
- 8 wt rod: 600-650 grain Skagit
- 8-9 wt rod: 600-650 grain Skagit
- 9 wt rod: 650 grain Skagit
- 10 wt rod: 750 grain Skagit

The selection of head weight is not critical. Note that a 600 grain Skagit head will cast beautifully with 7, 8 and 9 weight rods.

The weight of the tip is to be ignored in the above recommendations.

Rules of thumb for weight of sink tip that can be cast with a Skagit head.
- Novice to intermediate caster -- 1/3 the weight of the Skagit head.
- Intermediate to advanced -- 1/2 the weight of the Skagit head
- Advanced -- 2/3 the weight of the Skagit head.
See flyfishingresearch.net for the "half out and go" technique for casting heavy sink tips.

A Skagit friendly rod should bend deeply on the forward stroke. Try an old Sage 8150 brownie with a 650 grains Skagit head and any tip for a great feeling and casting rod.
 
#22 ·
Robert Pauli draws attention to another confusing aspect of the grain window conundrum, the spey caster's ability.

Rules of thumb for weight of sink tip that can be cast with a Skagit head.
- Novice to intermediate caster -- 1/3 the weight of the Skagit head.
- Intermediate to advanced -- 1/2 the weight of the Skagit head
- Advanced -- 2/3 the weight of the Skagit head.
I've grown out of certain head/tip combinations as my ability improved. It can happen fast, and you find yourself wondering if there's something wrong with your set up. Turns out, once in a blue moon, it's not you, it's your stuff.

Great thread. Learned a lot. Thanks all.
 
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