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Single hand rods fly line standard

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Merlin
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Single hand rods fly line standard

#1

Post by Merlin » Sat Oct 12, 2019 1:23 pm

There are technical reasons which can justify the current confusion about fly lines numbering. The original table, created during early 60s is no more completely followed by manufacturers (e.g. a #5 line is quoted at 200 grains instead of 140 grains – Rio In touch outbound short). Many people blame manufacturers but let’s see why this has likely happened.

When the table was defined, fly rods were only made of cane or glass, and were pretty slow by comparison to actual graphite rods. About ten years later the first graphite rods appeared on the market and since they were made of a single modulus material, they were just on the high side of the speed range. Since the beginning of the 21st century, new stiffer graphite fibers are used and bring the tackle speed above the range of what was produced during the 60s/70s. A race took place for lighter and faster rods. Today some rods are as fast as competition ones. Such rods can be swung faster and allow reaching extra distance for fishermen (I do not speak about competition here). This race caused a change in fly line production and we saw the weight of line increase on average. Although there is a tolerance in the original table, it is hard to find a line in the lower range; they all have weights above the target of the standard.

In fact, the change for a higher level of mass is due to the rise in speed of some fly rods. We all have a preferred speed range for the tackle, and if the tackle appears too fast for us, we can use another line number to compensate for it, even if the rod was not intentionally made for that line. But this is not the only reason. If one wants to make a pretty fast rod, it becomes stiffer and reaching the desired speed means that the corresponding line weight must rise, even if that speed is of a high level. This is also due to the fact that the equivalent mass of the rod goes down as the rod is lightened. Conversely it is for example very difficult to make a soft rod out of a stiff material; you have to choose a material which is soft enough to limit the speed of the rod. This phenomenon brings the line weight upwards for fast rods, although rod manufacturers can take care of using part of the actual specifications to stay as close as possible to the standard.

There is another phenomenon which is directly linked to casting, and which translates into larger tolerances in mass for higher lines by comparison to the tolerances of the table, which go from +/- 10% for the lightest line down to +/- 2.7% for the heaviest. Why that? Was it a question of manufacture tolerances during the 60s? I do not know, but what should be considered here first is the variation of speed of the tackle with the line weight. For example, if I consider that a 1% speed variation is acceptable all along the scale, then that can mean 20 grains variation between the minimum and the maximum specs for the lightest line (the value is 12 for the current specifications), but by 100 grains for the heaviest (and not 30 grains like today). Just the other way around, you see? If I want to match the 12 grains range of the lightest line for the heaviest line it must come up to 64 grains, and not 30.

The actual carry in mass can also bring confusion. If you us a saltwater rod, you likely use a head, they range from 30 to 50 feet (web info). Imagine you want to use the weight of a 50' carry for a 30' head, you just increase the weight of the line for a given number when using the short head (see example at the top). In fact the reference length of the specification (30') should vary with the fishing conditions, but this is too much for customers. Just unpalatable.

The difficulty we are facing is a trend for a rise in line weights, and as I explained above, this trend comes from an increase in speed for some rods, increasing the available speed range of commercial rods. The slow to medium fast rods are suited for the actual line standards, but the fast to very fast rods need a rise in weight, maybe we can say they are 0.5 numbers above as a starting point. However, the range of weight corresponding to a given speed variation enlarges the spectrum and the heaviest line could be in the 0.5 to 2 numbers range above the actual standard for fast rods. This is annoying, I know.

Merlin
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Lasse Karlsson
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Re: Single hand rods fly line standard

#2

Post by Lasse Karlsson » Sat Oct 12, 2019 4:06 pm

Interesting, since the jump in weight of lines didn't follow stiffer rods, but was a sales pitch for a certain brand.

That the outbound weighs more relates back to the original, that straight up told the truth, overweight to cast likely the shootinghead it mimicks. Now the sales blurp has changed, we are after all 15+ years down the line of Rio's copy of a other brands line, and most manufacturers and pseudo manufacturers have followed suit, it sells as most want to buy distance (not competition, that requires skill) and making a heavier short head line is the fastest fix there is, known already in the 60's...

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Paul Arden
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Re: Single hand rods fly line standard

#3

Post by Paul Arden » Sun Oct 13, 2019 5:54 am

It’s a very odd situation and completely backwards. Putting a heavier line on a rod that is too stiff is fine but not ideal. Better would be to buy the line weight that you want and then if you need a softer rod is to buy a rod with a lighter number.

We will be in a much better position once we have measured the true line weights. There are some issues that might be a problem, particularly with regards to head length and weight.

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Merlin
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Re: Single hand rods fly line standard

#4

Post by Merlin » Sun Oct 13, 2019 8:08 am

There is a material issue behind that, carbon fibers modulus can be varied, but not continuously (M33, M35, M40, M44, M48, M55, etc...), and there is a compromise to be found to match an objective. The upwards shift of the line scale is also the effect of a longer/heavier carry for very fast rods. On the paper you can find material characteristics that would fit your goal for speed, keeping the same line scale, but unfortunately, you will not find for sure the material combination to match that objective. And today you may not find the line (who is producing a true WF15?).

All did not came at once (faster rods, heavier lines), it was rather erratic with new line designs departing from the conventionnal specifications. If you want to see an example of upwards shift, which is the reason why I gave a technical look at the issue, look at line recommandations for the new Sector saltwater rods (Scott). Jim is known to stick to the standards, but for this particular series, he looked at available lines first. A practical approach given line weights availability. Tolerances were defined from casting, not from line manufacture, that was also something which draw my attention when analyzing information.

Merlin
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Re: Single hand rods fly line standard

#5

Post by gordonjudd » Mon Oct 14, 2019 7:31 pm

look at line recommendations for the new Sector saltwater rods (Scott). Jim is known to stick to the standards, but for this particular series, he looked at available lines first. A practical approach given line weights availability. Tolerances were defined from casting, not from line manufacture, that was also something which draw my attention when analyzing information.
Merlin,
Do you know what criteria Scott used to come up with their line matching recommendation? Was it based on getting a certain amount of rod loading for a given casting distance of 40-50 feet say, or was it based on getting maximum casting distances using a shooting head?

Just looking at how his min-max grain recommendations for a given 8 foot 10 inch rod series it appears the minimum values are close to the standard AFTMA value while the maximum value match up with AFTMA standard values that are .5 to 1.2 line weights higher.

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Re: Single hand rods fly line standard

#6

Post by Paul Arden » Tue Oct 15, 2019 5:34 am

Yesterday I linked to a page Steve Parton wrote for us 10 years ago! http://www.sexyloops.com/sparton/rodrating.shtml I found it interesting to reread to see how he cast rods - ie without double hauling and trying to cast as crappy as possible :D

As he points out one time we both separately labelled some Shakespeare blanks - about 50 of them. Something he didn’t know was about 10 of them broke in the first few casts!

Cheers, Paul
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Merlin
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Re: Single hand rods fly line standard

#7

Post by Merlin » Tue Oct 15, 2019 8:44 am

Hi Gordy

I do not know precisely, I think the tests are rather extensive. Among the tests there is a 30' load check if I remember well, but there are likely others.

Merlin
Fly rods are like women, they won't play if they're maltreated
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