MWithell wrote: ↑Sat Oct 22, 2022 6:19 pm
As I understand it, the weight of a fly line is in the line itself, so the load on the rod depends on the length of line out from the rod. The rod will work best when the optimum weight is in the air, so it's not quite so straightforward as matching the official line rating on the rod to the line with the same number. I haven't done fly fishing for ages, but I seem to recall that the AFTM is based on a standard length of line out from the tip ring. I can't remember the length - possibly ten yards, but it might be more.
…and that is how I have also considered it.
Iasgair has made the complete technical analysis on this-and selecting your own perfect match in another thread, which I have to confess, find parts of rather above my own dyed-in-the-wool ways of thinking..Sorry Sir!
Will stand corrected of course, but think that AFTM meant the American Fishing Tackle Manufactures and when some kind of standards were being worked out for line weight to rod ratio, it was factored in that the average cast was about 30 feet-so yes, ten yards.
When fly lines were all solid-mostly oil dressed silk-and tapered at the ends, it is clear that weight reduces pro-rata to line diameter and since silk weight was a known quantity, a series of letters were given to set diameters and everyone knew (more or less) where they were. The letter “A” being the thickest and “J” being the thinnest. A slight complication set in when a thicker diameter bellied salmon line was required so the decided on “AA”.
Cane rods of certain lengths were matched with set tapers; for example, the average 8’ rod was usually happy with a double tapered line designated “HDH” and a 9’ one with “HCH” .
A really heavy weight-forward salmon line could be “GAAF”!
It all worked fairly well but as you say, was not set in stone and if you only made shorter casts, the rod would work better with a size bigger.
You are also quite right in saying that there was-and still is-a “sweet spot”, an optimum distance where the rod and line -not forgetting the leader length-all cast in perfect harmony. Even with the newer “#” method of matching, which replaced the letters when “ bubble “ lines became popular, there has to be this distance; it’s the law of physics, but we constantly vary our casting distance so some kind of compromise has to be found…
…which is where Iasgair’s analysis comes in.
Being an “Old School has-been fly fisher, I find the various types of carbon fibre rod taper / action, plus the innumerable permutations of fly line tapers available today absolutely terrifying and almost beyond comprehension.
It’s rather like modern coarse fishing tackle . I can honestly say that I went into a large fishing tackle shop in Launceston, Cornwall whilst visiting their garden centre last year, to buy some spools of Rio tippet material and whilst there, had a browse through the carp/ coarse tackle division. I can hand on heart say that I did not have even the slightest clue what much of it could ever be used for..!
I came away with the growing feeling that there was little if any connection between the fishing I had known and what it has developed into..
Somehow, it seems to have lost it’s way and gone from being a simple pleasure to a box-ticking scientific technical exercise.
I just cannot relate to why this is …
…but must say, I’m rather glad!
wm+