You won't find one Phil which I think you are well aware of. Why should they have one when they can make you "buy to try". Doesn't mean it can't be measured or that it is unimportant (accelerometer might do for example).

I'm pretty sure I could tie a circle hook on the end of my fly line leader, dress it up with some hackle/feathers/beads.....toss it over the side and let the current float it away.....given enough time some dumb fish will manage to hook itself. No doubt millons upon millions of others could try it and validate my results. Wouldn't mean a "broom stick" makes a good fly rod. Lets be respectful even if methods aren't our "cup of tea", what we deem "sporting", or what has proven to work best for us.

Not like I feel I need to shoot my fish with a bow and arrow....but some do. However I do admit to jumping over the side and spearing them:)

Russ in Hollywood, FL.

I was NOT "well aware of" the lack of any objective measurement of rod "sensitivity". Your comment led me to believe such information is available. I asked an honest question and expected an honest answer naming a source of useful information I could share with customers? BTW: Many tarpon guides have switched to flies tied on circle hooks. The angler doesn't worry about sensitivity or setting the hook, he just holds tight and lets the tarpon hook itself. Guides report a jump in hook-up to hit ratios.

Russell: See article on tarpon fly circle hooks by Dr. Aaron Adams in "Fisherman's Coast".

Russell: See article on tarpon fly circle hooks by Dr. Aaron Adams in "Fisherman's Coast".

The comment was made that sensitivity in a fly rod doesn't matter I disagree I believe that sensitivity and action of the blank make a big difference in the way a fly rod casts. you definitely need to feel the rod load on the back cast and sensitivity also is important when fishing a sinking line, or nyph.

In times past, when the word sensitivity came up, I have tried to stay out of the discussion.

Yes, as David stated - sensitivity and his definition can be measured, and it is clearly a correct term and definition.

However, I often think that when the subject of rod sensitivity comes up - many folks are referring to something other than the classic definition of a physical measurement of sensitivity.

I often think that many folks use the word "sensitivity" to cover all of the aspects of a rod, that allows the fisherman to simply catch more and better fish.

Then, when asked about the rod and why they are catching more fish - simply use the word "sensitive" to cover all of the aspects of the rod. Some of which are really not part of the classic scientific definition of a sensitive rod.

So, when asked about the characteristics of the rod - the person simply says that it is a very sensitive rod.

Hence, my reluctance on engaging on any discussion of sensitive is because of this feeling about rods by some folks.

Good luck

Nobody has mentioned the CCF frequency ratio, and I still have no idea where to find a table listing the CCF ratios of rod blanks. The CCF ratio of a fly rod depends upon the line as well as the rod, making such a chart a tough task. Of course feeling the line "tug" to start the forecast and back cast with a fly rod is essential, but ALL blanks transmit this "tug" - regardless of their "frequency," if the fly line is heavy enough. A sizable percentage of fly casters struggle to cast 50', no matter how "sensitive" their fly rod. A good percentage of fly casters adept at the double-haul can cast a fly line farther than 50' with just their arm and hands, even with gloves on! Not much sensitivity involved there.

Phil, I have no idea if anyone has ever measured and recorded a rod blanks ability to transmit vibrations. I don't need empirical evidence to convince me that some rods, and blanks transmit vibration better than others. I can feel the difference. The word "feel" does not necessarily imply an emotion and therefore make it open to subjectivity.

32 degree air feels colder than 100 degree air is not a subjective statement. It's fact. How much colder does it feel? That's subjective.

The CCF doesn't require a fly line to obtain that measurement. There is no database that I know of at this time, but you can certainly perform the measurement yourself. Of course, you have to have the blank or rod in hand to do so. Pity more manufacturers won't use it and publish the data, but most feel that the ability for fishermen and builders to accurately compare blanks from one company to another might be detrimental to their sales.

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On his online article "The Common Cents System (Simplified)" Dr. William Hanneman wrote under CCF (common cents frequency): ". . . the feel or frequency of one's fly rod outfit is a function of both the rod and the line." He proceeds to explain how a rod's "feel/frequency" [sensitivity?] can be measured and quantified. I am a big fan of data that can be quantified, verified and replicated, as opposed to advertising hype which requires only undocumented belief. I won't buy every blank out there and test its resonance frequency any more than I would buy a blank because anybody says, "It feels sensitive to me." Different strokes for different folks.

If you go back further to the article on how to take the CCF measurement, you'll see that a fly line is not required.

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I don't believe the CCF is a valid measure of sensitivity.
It does measure loaded blank frequency versus gravity.
The load weight is comparable to fly line weight designations.
By supporting the blank horizontally the frequency is damped by gravity in one direction. The rod must be vertical and the force applied perpendicular to the blank.
Sensitivity is the measurement of the differences in vibration between the two ends of the blank.
A fixed vibration is induced in the rod tip and the vibration is measured at the butt. The loss in measured vibration reflects the rods ability to transmit vibration. The only way I can see of measuring this efficiency loss is the use of oscilloscope. The area under the amplitude and frequency curve may be measured at both ends and an efficiency calculated.
The closer the curves match the more efficient the blank.
Multiple section blanks will be less efficient. Poorly designed tapers will be less efficient. Poor mass distribution will be less efficient.
Poor manufacturing technique will be less efficient.
The effects can be measured and quantified, but I don't believe most fisherman or rod builders could accurately analyze the results.
You still have the problem of the subjective nature of the individual with "hands on rod" .

CCF does not claim to be a measure of sensitivity. It is, however, a means of quantifying efficiency, which plays a role in sensitivity.

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A chain is no stronger than its weakest link, and the connection between a reel and a fish is no more sensitive than its least sensitive component. What specific type of fishing lines transmit the most sensitivity and under what conditions, or is there no appreciable difference between lines in terms of sensitivity?

Phil, as a fly fisherman I would imagine you have fished other type of reels and noticed a much more direct connection to the fish with a fly rod. At least I do....and it is directly related to less strecth in a fly line.

But I'm going to submit that all your thinking has been about detecting the strike. For me sensitivity comes into play well before the strike and long after. For example, a live bait can clue me in on when I need to pay extra attention because I can "feel" him getting nervous. Once the fish is hooked up, I can feel his mood/condition in the fight....his head shakes and such....and know when I can apply maximum pressure and when I must slack off and let him run.

Russ in Hollywood, FL.

Russ: I concur about detecting baitfish nervousness. I see it often while my rod is in a sand spike. I wait until rod movement tells me my circle hook has done its job and the fish is taking drag, mosey down to it, lift the rod and tighten the drag. Works for me. I know some freshwater bass fishermen use fluorocarbon monofilament because they feel it is more sensitive than nylon, and apparently gelspun braid also. I do not know of any verifiable charts comparing the sensitivity of different types or diameters of line, or whether this sensitivity changes with water temperature. The differences may be small, but the lack of concrete measurements of rod sensitivity in general are apparently so small or elusive that they can't be measured at all?