Define 'Parabolic'

[Mike McGuire]

A parabolic rod is a rod whose taper is exactly a section of a parabola or falls very close to one. It has frequently been asserted otherwise, but as I eyeballed some plots of tapers of rods called parabolic, that's what they did look like. So I figured out how to do a parabolic regression using an Excel spreadsheet. What this does is find the parameters of a parabola that falls closest to a taper that is input to it, and then plots it.
Here is the result for a Para 15 as given in George Maurer's book.


Here's another version of the Para 15 from the RodDNA database


There is a bit more variation with respect to the best fitting curve but it's still a decent fit. In the RodDNA database I went through all the Para series tapers and some of the Pezon et Michel tapers with parabolic in their names and found similar results. The Powell A and C tapers are exactly sections of a parabola, a consequence of the recipe for constructing them. I have an article up on my web site that discusses all this and has the spreadsheet available for download--warning--for mathematically mature audiences.

Mike

[SideChannel]

Mike,

Thank you for your informative post.

Greg

[thramerrods]

no......



sorry, couldn't help myself.

i suppose saying they are full working rods that cast out of the butt and you know one when you are using it would be no real help though
aj

[mer]

Mike, I believe it's the stress curve approximates a parabola, not the dimensions. My understanding is that a parabolic rod will have dimensions a little skinnier in the butt section, a little fatter in the mid than a straight line taper for the same butt and tip dimensions. I think Ray Gould has a good explanation.

[czkid]

Like AJ says... you'll know it when you cast it. I've got a couple extreme paras that I love handing to a "hot shot" graphite kid and watching the expression on his face when all he ends up with is a pile of line at his feet... priceless.

Ralph

[Mike McGuire]

Mike, I believe it's the stress curve approximates a parabola, not the dimensions. My understanding is that a parabolic rod will have dimensions a little skinnier in the butt section, a little fatter in the mid than a straight line taper for the same butt and tip dimensions. I think Ray Gould has a good explanation.

I don't think you have understood the plots in my post above. The blue line is the taper, the red line the closest fitting parabolic curve. The green line is the stress curve of the actual taper and the magenta line is the stress curve of that closest fitting parabola. Neither of those stress curves looks anything like a parabola.

I have both of Gould's books, and find they have a lot of useful information in them. However his explanation of parabolic is all wet. He assumes without justification or proof a stress curve which is parabolic and obtains a taper from that which he then names parabolic.

Mike

[quashnet]

You could take a small arc of the red line, locate an axis of symmetry for that arc and call it a parabolic arc. I guess it's possible that this arc tells us something about the rod, but Charles Ritz, who developed the parabolic rod, would not recognize it. As Ritz wrote, "This is the action which I have called 'Parabolic,' though the term is only a figure of speech, and the curve of the rod has absolutely nothing to do with a parabola." (A Fly Fisher's Life). Ritz made his first parabolic rod in 1933, and first brought one to the USA in 1937. He described in detail his definitions and working methods in an interview with Al McClane, published as "The Parabolic Rod" in the August 1948 issue of Field and Stream. Ritz did not use equations and curves. Ritz literally built oversized prototypes and then filed them down at streamside to get the action he wanted, after which the resultant rod was re-measured, and he would then try to build something yet closer to the ideal. It was very much a hunt-and-peck style that I suppose would be considered primitive today. Young was influenced by Ritz and at first called his rods "Modified American Parabolics" because they were based on the originals from France. Young's ideas are primarily written up and illustrated in his catalogs, as well as some letters. All of this is getting far away of course from the OP's desire to have people describe in their own words what parabolic action means to them, and so it is perfectly valid to say that for you it means a curve that appears on a graph. But the only curves I have seen from either Ritz or Young were drawings or photographs of how a finished rod bent under static load or casting stresses.

[Mike McGuire]

You could take a small arc of the red line, locate an axis of symmetry for that arc and call it a parabolic arc. I guess it's possible that this arc tells us something about the rod, but Charles Ritz, who developed the parabolic rod, would not recognize it. As Ritz wrote, "This is the action which I have called 'Parabolic,' though the term is only a figure of speech, and the curve of the rod has absolutely nothing to do with a parabola." (A Fly Fisher's Life). ...

Quash

Here is the big picture of the parabolic fit to the Para 15 shown above.

It is a real parabola, not some hack of "taking a small arc and locating an axis of symmetry." However I have no problem believing as you say that Ritz, Young and the rest came up with their tapers by a trial and error process which didn't intentionally use parabolic curves. The fact that these tapers do fit rather closely to parabolas then is a matter of life imitating art.

The way I came around to this is being a west coast guy, I favor E. C. Powell's approach to taper design. The basics of it were described in an article in Best of the Planing Form 2 by Ed Hartzell. From it, I was able to show that his A and C tapers were both exactly sections of parabolas, the C taper being parabolic and the A taper anti-parabolic in the sense of this discussion. The article gave a good idea of a suitable range of parameters for A tapers, but not much on C tapers. So what I did was "reverse engineer" tapers like the Para 15 by fitting parabolic curves to them which gave me workable C taper parameters. I have since designed and made several rods using this approach and found them quite pleasing. If you make it out to the Bay Area and the Golden Gate Casting Club again, I would be delighted to have you cast them.

Mike

[quashnet]

It would be exciting indeed to find synergy between what Ritz started eighty years ago via trial-and-error and your modern idea of envisioning the taper as fitted to a parabolic curve (actually, Ritz only rediscovered the taper and called it "parabolic." Genio C. Scott perfectly described parabolic action in his 1869 book, and Gnome has pointed out that the action was known a century earlier from the Castle Connell rods, and who knows how long before that).

The tools available to earlier generations of rod makers were limited, but their creativity was boundless. So much the better if your methods help to showcase and perhaps further their achievement. Many, many years ago I had some long-distance communications with Ed Hartzell, and may still have a letter or two of his drifting around the file cabinet. If I have opportunity in the future to be anywhere near the Golden Gate Casting Club, I would very much enjoy casting the rods you have made.

[Mahseer]

I believe that the great British angler Fred Buller MBE referred to this taper as a "pair of bollocks" - but I have no idea of what he meant by this...

[2S1Squirrelgrip2]

NEVER MIND THE BOLLOCKS!

[mattcliff]

According to Hoagy Carmichael's book, Everett Garrison claimed to have originally coined the term "parabolic" to describe the Ritz rod developed after the famous bicycle accident. He clearly did not mean it as a compliment. He says he remarked to Ritz that if you just took a straight plank of uniform thickness, anchored one end of it to a wall, and hung a weight on the end, "the stress curve would be a true parabola." Ritz, apparently oblivious to the irony, responded: "That's it! This is the Parabolic Rod."

All this is related on page 238 of "A Master's Guide."

[Mike McGuire]

According to Hoagy Carmichael's book, Everett Garrison claimed to have originally coined the term "parabolic" to describe the Ritz rod developed after the famous bicycle accident. He clearly did not mean it as a compliment. He says he remarked to Ritz that if you just took a straight plank of uniform thickness, anchored one end of it to a wall, and hung a weight on the end, "the stress curve would be a true parabola." Ritz, apparently oblivious to the irony, responded: "That's it! This is the Parabolic Rod."
All this is related on page 238 of "A Master's Guide."

This is what you will find at this link to the article on beam theory in Wikipedia (warning--heavy math content). However the stress curves of rod we consider parabolic, e.g. the Paul Young Para series don't look much like parabolas at all while the tapers do--apparently not by intent, but that's what they are. The effect of Garrison's crack, considering his heavy influence on rodmaking, has been to seriously muddy the waters on just what parabolic means. This for example led Gould astray.

Mike

[bluesjay]

Hi Guys, Man, differentially quadratic. [Or is it quadradically differential? I can't remember, or tell.] I find the rods are mostly fast taper rods with no taper into the grip. They cast great! Jay Edwards

[deeply shallow]

In the July 1998, issue of "The Bamboo Fly Rod" magazine, Per Brandin wrote an extensively researched review called "Bamboo Rod Action and Design". In the article he credits Charles Ritz with principally developing the parabolic action. Ritz is quoted from his memoir "Flyfishers Life" as being a self proclaimed "jerky jerky" caster. Mr. Brandin goes on to say that people who like to apply power to a rod very suddenly often do well with a parabolic action because the soft spot resulting from the regressive taper above the grip (as opposed to a swelled butt leading to a progressive taper) will absorb the shock and store it momentarily, delivering the energy to the tip at the end of the casting stroke where it belongs.

I've posted this before but it is also probably worth referencing.
Ernest Schwiebert, in "Trout Tackle - Part Two" writes that when Charles Ritz came to the U.S. in 1936 , he had Ed Payne build him the first American rod in the true parabolic action.
"Parabolic action means literally this: the working portion of the rod is the lower one-third, next to the grip. The middle one third acts as a lever, to deliver the power created by the lower rod, while the top one third imparts the power to the line. The upper and lower third do most of the bending during the cast. The middle third of the rod bends very little, since it functions as a lever."
Schwiebert also then opines "True parabolic action is not satisfactory for the average angler."

[hoagy b carmichael]

Gentlemen:

In an effort to add some clarity to this interesting subject I would like to quote from a letter written to me by Alfred Miller (Sparse Grey Hackle) in 1977 on this subject. I certainly do not intend to injure our friends in France, or anywhere else, but Sparse was in the middle of all this and I feel his recollections important to the subject matter here. I quote:

"Later, Jack [John Alden Knight] sucked Garry [Everett Garrison] in a little on his "parabolic" taper a brand-new invention by the great Knight - according to him. Of course, one Enright, an Irish maker of the famous Castleconnell type of salmon rod, had come over in 1909 to the Anglers' Club national casting tournament, and had beaten the pants off all the competition in the two-handed salmon event. He was a big, powerful bruiser and yet the only member of the Anglers' Club who could cast with it was the diminutive George LaBranch; so Enright gave that rod and a similarly designed trout rod to George, and after George's death his widow gave them to me and I gave them to the Anglers' Club collection."

"Garry cut a few rods to Jack;'s modified (parabolic) tapers to see if Jack could sell them, but nobody bought them after trying one or two casts; one had to fish nothing but parabolics and get used to that slow, top-heavy action. Jack finally sold Charlie Ritz, who soon found he had to make some fundamental modifications; I think he still retains the name or something like it. He's such a horse.... artist that you can never tell just what Charles Ritz does mean."

Sparse goes on in a different letter to refute the largely baseless story that Mr. Ritz apparently made up. "I think the Ritz story about about the messenger boy (his fly rod was broken in the spokes of his bicycle), etc. is so much horse..... Ritz was a good merchant and a money maker, and he needed a few things to make Pezon & Michel unique and desirable."

So, there from Sparse is his version of the origins of the "parabolic" taper design. Jack Knight was not an engineer, as was Garrison, and the term "parabola" was probably not in Mr. Knight's vocabulary. Did Mr. Garrison first coin the term "parabolic" to the 8'0" rods made for Knight? I think so. It certainly was not Mr. Ritz....

H. Carmichael

[quashnet]

Now there is a good story! Many thanks!

Ritz's bicycle accident story is always in the back of mind when reading John Alden Knight's story of how he started with a loose and limber 10'6" rod and cut it back bit by bit, trying it out for size and action, until he had a 9'6" rod that became the basis for Leonard's Knight 99 bass bug rod (Black Bass, 1949).

Could it be that Ritz's story was a deliberate jab at John Alden Knight's less-than-scientific method (among whose other claims to fame was the Solunar Tables, consistently spoofed by Ed Zern)?

According to Knight, in 1937 Ritz gave him the first Luxor spinning reel ever brought to the USA.

[JeffG]

Where would you attach a reel to a 'Trebuchet' Boo, I am totally interested have you ever seen a "Smugglers Trebuchet"? would definately come in handy for some of the small streams I fish.
I am picturing some very rapid parabolic tendencies and potential dislocation to come from such a device.
but I will try anything once, twice if I survive the first attempt.. Ha ha,
Jeff

[bassman]

Parabolic... and angler who is unseady on their feet, generally a poor wader with a drinking problem....

...Also they can drool a bit and slurr their speech when confronted streamside so care must be taken when approaching these "parabolics" for questioning.
J.

I have to go back to this post on page 1 to find anything I can really understand. Page 2 might have some humor in it, but it buzzed over the top of my head if there was.

[bassman]

Like AJ says... you'll know it when you cast it. I've got a couple extreme paras that I love handing to a "hot shot" graphite kid and watching the expression on his face when all he ends up with is a pile of line at his feet... priceless.

Ralph

And Ralph, pray tell how this differs from every 4th or 5th cast I make regardless of rod composition or action?