A "Table of Effects of TRIMMING or EXTENDING a ROD BLANK" can be ffound at: [www.rodbuilding.org] . This subject came up over the weekend. Hopefully, this will conveniently provide some general guidelines.

In summary: “If you want a SHORTER version of the rod with the same action, trim from the BUTT. If you want a STIFFER version of the same rod blank, carefully trim from the TIP. If you want a LONGER version of the rod with the same action, EXTEND from the BUTT The most dramatic alteration of a rod blank's properties would be by trimming its tip. Trimming or extending the rod blank from the butt end has a less pronounced effect on the rod blank's action / taper.”

-Cliff Hall, Gainesville, FL-USA +++

Very good Cliff -- short and sweet.

Thanks, Bill - I'm working on it ! "KISS", -Cliff Hall +++

Shortening any rod blank from either end will result in a slower action. How much depends on how much you trim.

Extending any rod blank from the butt (with a piece at least as stiff as the rod butt section) will create a faster action.

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From: Emory J. Harry
The Effect on Resonant Frequency from Trimming or Extending a Rod Blank:
- Shortening by cutting from the tip will increase the resonant frequency.
- Shortening by cutting from the butt will slightly increase the resonant frequency.
- Lengthening by extending the butt will lower the resonant frequency.

From Billy J. Vivona:
- Shortening the rod from Butt or Tip will give you a shorter rod
- Extending the rod from the butt will result in a longer rod.
Billy 1:40

Touche, Billy !

I may be wrong but aren't action and resonant frequency two different things???

I am no expert in the "resonant frequency" factor of rod properties, but I think I can answer this question without introducing more confusion. (LOL!)

Q: Aren't rod ACTION and "resonant frequency" two different things?
A: Yes. They are two different things. But they are related; they are not entirely independent of each other. A faster action rod is likely to have a higher resonant frequency. Trimming a given rod blank from the tip will increase the resonant frequency of that rod, because that reduces the rod's overall length, overall mass and the mass at the tip.

Please refer to Emory Harry's article in RMM-8(3), page 22-29, "Guide Weight and Rod Performance" for a fuller discussion of this subject. -Cliff Hall+++ ... (Should I have stopped here?)

Epilogue:
Resonant frequency is affected by rod length, overall rod mass, and the point distribution of that mass and additional masses (like guides and thread wraps) along the rod. Increasing the point masses (more guides or thread and epoxy) reduces the resonant frequency. Trimming the rod tip reduces the rod's length and mass at the rod tip, both of which tend to increase the resonant frequency. Changes in mass near the rod tip have a much greater affect on resonant frequency than a change in mass of the same magnitude at a location nearer the rod butt. This is a matter of lever arm length.

So, trimming the tip of a given rod will technically produce a more moderate action and will alter the rod taper. The tip-trimmed rod will always become stiffer. And that will translate into an increase in the rod blank's resonant frequency. And that may make the new rod feel more sensitive. Beyond that, I am reluctant to comment, because that's about as much as I understand about resonant frequency at this point.

How my senses of touch and alertness respond to a given resonant frequency is still a very relevant factor here that is very hard to quantify and integrate with this knowledge of a raw resonant frequency. Would I (or you) be able to better detect a subtle "bump" at one frequency than another? Would some fisherman better detect an impulse at a lower frequency than at a higher one? Would a certain range or specific frequency be better than another for a certain type of quarry or certain range of lure weights or type of lure or method of fishing? Surely, every fisherman who ever touches a rod is looking for his fit to these questions and parameters. And they are as varied as the fisherman themselves. (So, I'll quit while I'm still ahead.)

Please refer to Emory Harry's article in RMM-8(3), page 22-29, "Guide Weight and Rod Performance" for a fuller discussion of this subject. -Cliff Hall+++

"...Would I (or you) be able to better detect a subtle "bump" at one frequency than another? Would some fisherman better detect an impulse at a lower frequency than at a higher one? Would a certain range or specific frequency be better than another for a certain type of quarry or certain range of lure weights or type of lure or method of fishing? Surely, every fisherman who ever touches a rod is looking for his fit to these questions and parameters. And they are as varied as the fisherman themselves. (So, I'll quit while I'm still ahead.) "

I'm sure Emory will weigh in on this once he sees it. I'd need to think it over a bit more, but generally a rod with a higher RF will be more sensitive than one with a lower RF. Not such much because of the frequency itself - but because the things that cause one to have a higher RF are the same things that generally cause a rod to be more sensitive. Then again, I'm not sure we've ever gotten a handle on what we all refer to as "sensitive."

For practical purposes, I think fishermen should try to relate resonant frequency to how quickly a rod reacts and/or recovers. Rods with higher RF react more quickly to your input. They also stop oscillating or vibrating more quickly than those with a lower RF. So as far as what RF range would provide the greater feel for an angler, you can envision which of your current crop of rods is the most sensitive for you and consider its action, power and material make-up. I may be off the mark, but I doubt many would choose an older glass rod, with perhaps a moderate or slow action and heavy steel guides as the most sensitive in their stable. I'd have to say that the rods most fishermen would likely select as their more sensitive models would have higher, rather than lower RF.

I would also suggest the same thing Cliff did - read Emory's article for a more thorough discourse on RF and how it relates to action, power and material.
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