Terminology

[Tangled]

A pretty difficult task.

Yes it seems that way but it's important to try I think. From my discussions with others, people are awfully confused about it. Manufactures use terms like "traditional action" and "fast recovery rate" and the retailers simply copy them in the marketing blurb as though everyone is thinking the same thought when they read them. It must make a newbie's head spin.

In 1979 Fly Fisherman published a review of tackle manufacturers' opinion on rod characteristics (like action, speed, etc.). Makers were Russ Peak, Harry Wilson, Walton Powell, Howard Steere, Tom Maxwell and Jim Green.

In 2004 Fly rod & Reel did quite the same with Jason Brunner, Jim Bartschi, Tom Dorsey, Sam Druckman, Steve Rajeff, Jim Rowinsky, Jerry Siem and George Swanson.

Don't suppose any of those are available online?

If we write a terminology, I'm sure that it will be impossible to get an agreement in between a reasonable number of people from this forum

Since when has this placed concerned itself with lack of agreement? :-)

But actually I'm not so sure, having read quite a lot of the site I suspect there's not much difference amongst you. That's a recipe for disagreement in itself I guess.

[Tangled]

I suppose I could start us off. These are definitions culled from either here or roadbuilding.org.
Frequency is a sentence from Daniel Le Breton on November 24, 2014 in Casting Mechanics but could be expanded.

Rod Action
Where most of the initial flex in a rod blank takes place. Fast Action rods will flex mostly in the upper 1/3rd of their length. Moderate Action rods in the upper 1/2 of their length. Slow Action rods flex along their entire length. *See also "Progressive Action."

Progressive Action
Term used to describe a rod blank that continues to bend farther back towards the butt end as load upon it is increased. As the load is increased, the blank responds by shifting the load onto the larger, more powerful area towards the middle and rear of the blank. (Also called a traditional or slow Action)

Parabolic Action
An old term originally used to describe the regular curve of some bamboo rods under load. (Also often called a Progressive, Traditional or Slow Action)

Action Angle
A relative measurement (in degrees) of rod or blank's action. Originated with the Common Cents System.

Fast Tip
Normally used to describe a rod with a very fast action. A rod with a powerful butt section and a much softer tip.

Modulus
"Modulus of Elasticity," refers to the relationship between stress and strain. In more simple terms relative to rod building, it usually defines the stiffness to weight ratio of the fibres used to construct the rod blank. Generally speaking, the higher the modulus of the fibres used to make the blank, the lighter the resulting blank can be for any given stiffness.

Power
A rod or blank's stiffness or resistance to bending. [A rod marked #6 is more powerful than a rod marked #5 - in the same model range]

Rod Frequency
A fly-rod has a natural frequency which is the number of vibration cycles per unit of time. It is usually expressed in Hertz in the technical domain: 1 Hz (Hertz) = 1 cycle per second. Rod frequency determines Recovery Time.

Recovery Time
How quickly the bent rod returns to its natural, straight position.

Rod Feel
How a rod feels to the individual when casting. It’s the combined effect of all the attributes of a rod listed above. Plus a bit of magic dust, desire, expectation and confirmation bias. [Tangled]

Sources
https://www.rodbuilding.org/glossary
https://www.sexyloops.com/flycasting/te ... nyms.shtml
http://fly-fish-guide.net/blog/fly-rod-frequency/

[Merlin]

I contributed to John Symonds’s blog for a couple of years.
To me there must be some technical background for all the definitions used. If you are interested I published an article on parabolic rods in Powerfibers magazine (downloadable). To make things simple it is a deep butt action (the deepest likely).

In your list there are a few arguable definitions, just taking a few:
• Progressive action: technically all rods are progressive, if you consider their amount of bend as line length is increased. To my knowledge it was E.E. Garrison who introduced the concept, but he was referring to the fact that energy in the rod goes progressively through the rod, it starts from the butt and ends in the tip at some speed. It was also called semi parabolic action later on.
• Rod feel is just impossible to quantify, it is very personal and the subject has not been sufficiently investigated (what do casters feel when using the same outfit?).
• Modulus relates to material (cane, glass, graphite) and not to rod characteristics per se.
Ideally someone should have some casting capability to ease his understanding of rod terminology.

Merlin

[Tangled]

I contributed to John Symonds’s blog for a couple of years.
To me there must be some technical background for all the definitions used. If you are interested I published an article on parabolic rods in Powerfibers magazine (downloadable).

I'm interested! Do you have a link?

• Progressive action: technically all rods are progressive.

Yes, it's rather meaningless, I alway took it to just mean slow.

• Rod feel is just impossible to quantify, it is very personal and the subject has not been sufficiently investigated (what do casters feel when using the same outfit?).

That one was tongue firmly in cheek.

[Merlin]

I’m away from home for a dozen of days. I can’t find the link but I can send you a copy when I’ m back, thanks to send me a mail adress through Sexyloops mail facility.

Merlin

[James9118]

I've got an overwhelming feeling that those who coined the phrase 'parabolic action' in the past in relation to fishing rods didn't actual know, or bother looking up what a parabola is.

I very much doubt that anyone can show me a rod bend profile that you can't fit a parabola to, unless they're talking about stuff with flat spots where the joints are. As such, 'parabolic action' is just marketing BS, no different from today's statements offering superior tracking, lightning fast recoveries etc. All rods bend, and all of those bends could be described by a parabola.

James.

[Paul Arden]

Arguably they are all progressive too. In fact I woukd argue that is one of the most important attributes of any fishing pole.

Cheers, Paul

[Merlin]

The name "parabola" comes from the reference to the stress curve of a cantilever beam made by Everett Garrison, a rodmaker having an engineering degree. The cantilever beam is an analogy with a rod of little taper which was promoted by Charles Ritz (rod designer for Pezon & Michel). Ritz took the name and called the action of such rods "parabolic". Pure marketing for sure.

Then people started to speak of parabola for the bends of rods, for rod tapers, etc. The article I wrote tells the story of the "parabolic" rod.

Merlin

[James9118]

The name "parabola" comes from the reference to the stress curve of a cantilever beam made by Everett Garrison, a rodmaker having an engineering degree.

Merlin

I think you're a couple of thousand years late with your reference. Look up Apollonius in the BC era.

James

[VGB]

I think you're a couple of thousand years late with your reference. Look up Apollonius in the BC era.

So apart from inventing fishing rods, what did the Ancient Greeks ever do for us?