Tom Kirkman Wrote:
-------------------------------------------------------
> Building on the spine won't increase performance.
> It won't necessarily degrade performance, but it
> will decrease the blank's deadlift capacity.
>

Wouldn't this depend on the direction of the spining? I always put the soft side up because I want my backswing on a cast to flow naturally into the soft spot and come straight out of it on the forward swing of the cast. If I reversed this and put the soft side down, then I can agree the deadlift capacity might be slightly diminished, but I do it the opposite way with soft side up rather than down, so my deadlift capacity is not diminished this way as I understand it.

If I were to put the soft side down, then when I flow into my backswing on a cast the rod is being asked to bend at one of the strongest places and physics tells me the rod will try and resist going straight into that hard side and will try and skew off to one side or the other in my backswiing and could throw off my aim for my cast- which my muscles would try and compensate for to some degree, but for my way of doing it I prefer soft side up, and I could not care less about any straight axis- that's for selling rods I have read above- so I spine my rods to fit my way of casting more than anything else.

So I agree with you building on the spine will not increase performance, and it won't degrade performance, and my way with soft side up will not decrease deadlift, but it will in my mind give me a more predictable casting accuracy going with the flow of the rod rather than against its natural will to bend at one spot more so than others. And I am comfortable with continuing to do it this way and will never be concerned about any straight axis. And this is the beauty of custom rod building- to each their own and they all catch fish!

And oddly enough, as I listen to Gary Loomis describe how he spines a rod without using the lingo, I find his way is now my way as well. Soft side up. He is very clear on this for his rods...

[youtu.be]

The lever arm effect of the guides determine rod twist, not spine orientation. And no particular spine orientation can offset the lever arm effect of the guides.

Rod blanks do not want to bend in any direction. Bend one on any axis, release it and watch what happens - it'll come back to straight. You have misinterpreted Gary's comments in the video - he's advocating for orienting the blank on its straightest (stiffest) axis, belly down. That's the straightest axis, not the spine. The stiffest axis is never the spine nor the opposite of the spine.

................

And the lesson we have learned today ......... when you challenge and think you may have the legendary Tom Kirkman on the ropes it's only an illusion prepare to be body slammed.

I agreed with Tom except for the decrease in deadlift based on orientation of spine. If soft side was down, then yes there would be a slight decrease, if soft side is up then I can not agree with it. That is the only point I disagreed upon because spine can be used two ways and Tom's response only deals with one way which was the point I was making about it because he did not say how the spine was used.

Tom and I agree, and Gary and I actually agree. He clearly showed how the soft side is kept up. End of story. And this is the point I was trying to make and Gary also made it very very clear.

I use micro guides. There is virtually no such lever effect in operation during the cast. Line flow is right on the blank. Now if the guides were much taller then maybe there would be a little validity to it but a cast is a no load situation once released so what force is causing leveraging and where on the rod is this happening and when and does it matter is the real question? To me, this is not relevant. Micro guides are so short and line so close to the blank this type of concern is virtually non-existent.

It is far more important to Gary Loomis and to me that the rod bend on the backswing into the rod's natural soft spot bend.

Gary clearly showed guides go on side of blank opposite the soft bend side if a spinning rod. No misunderstanding at all. Watch the video... he shows finding the soft side and then says put the guides on the opposite side if a spinning rod and on the top or soft side if a baitcast rod. Very clear. And we agree.

Curious, did anyone see Gary sighting down the rod for straight axis? Nope. He clearly showed how to find the soft side and put the guides on the blank BECAUSE of the location of the soft side. Not one word in video of Gary about straight axis. All about the bend only. He was very clear at least to me.



Edited 2 time(s). Last edit at 04/17/2021 12:28AM by Kent Griffith.

Tom Kirkman Wrote:
-------------------------------------------------------
> The lever arm effect of the guides determine rod
> twist, not spine orientation. And no particular
> spine orientation can offset the lever arm effect
> of the guides.
>
> Rod blanks do not want to bend in any direction.
> Bend one on any axis, release it and watch what
> happens - it'll come back to straight. You have
> misinterpreted Gary's comments in the video - he's
> advocating for orienting the blank on its
> straightest (stiffest) axis, belly down. That's
> the straightest axis, not the spine. The stiffest
> axis is never the spine nor the opposite of the
> spine.
>
> ................

Just saw this comment Tom after the other one...

As I said I use only micro guides which are so short there is no appreciable lever effect. Not possible. On the backswing, the line pulling on the tip of my rod is not held away from the blank far enough to be a lever. It is actually like 1mm away from the blank or less. Any lever effect is so minimal it is nonexistent with the micro guides I use. Now taller guides might be a different story. But with the micro guides I use, this is a non-issue. The distance my line flows from the blank is less than an o in this text.

I disagree with you on rod blanks do not want to bend in any direction. There is clearly one or more places or sides where a blank will bend more easily than others, and Gary Loomis even says this in the video. Very clearly says so. I agree a rod does not bend on its own, but when a force is applied to a rod to bend it, it does usually have a weakest side which is precisely what Gary did this video on to find and locate and goes to extremes to explain how to put your fingers on the blank and twist it and how the blank responds by snapping right back into it preferred bend. Very clear. This is classic spining even though Gary did not want to use that word because of the confusion over what spine even means.

I also disagree Gary is orientating a blank on its straightest axis in the video. To do that would require a tool that is a laboratory reference straight edge to gauge the rod blank against to find that "straightest axis." To me, bending a rod is not finding the straightest axis. On this I disagree. Straight means straight. Bent is not straight to me. Gary bends the rod and finds the location the rod bends most easily and declares very clearly once this soft side is found, now he knows where to put the guides and he says very clearly for a spinning rod put them on the blank opposite the soft side, and a baitcast rod to put them on top or on the soft side.

This is classic spining of a rod and there are numerous videos on youtube showing the precise exact same method for locating this spine effect.

Gary did say there has been a lot written about what a spine is or is not and he did not want to get into that. He said he knows where guides go based on how a rod bends. Not how straight it is.

To me there are 2 sides to spining a rod. It is either soft side up or down. Hard side up or down. Different people have differing takes on precisely what the spine is, and in my book I use the soft side precisely how Gary demonstrated it and I put the guides on my rods precisely how Gary Loomis does it. There is absolutely no difference in how Gary does to how I do it. One and the same. No misunderstanding as I see it.

That's my story and I'm sticking to it.

I transcribed the important parts of Gary Loomis exact words from this video...

Question from man interviewing Gary: "Can you give us your point of view on the spline of the rod blanks?"

Gary Loomis:

"We have a little tag here to show you where it will seek out.

You bend it down like this and then you take your fingers here and rotate the blank and you will find that the blank will find its easiest place where it wants to stay. As you can see I can move it around and it still wants to stay there. If I try to turn it around and get it off that spine (Spline?) of the blank it wants to go right back. What it really says is the blank wants to bend easier this way than it does this way (shows opposite bend).

90% of the time if there is a bend in the rod it will be this way anyway (showing soft side up).

Whether the top is the spine or bottom is the spine I don't care. What I do care about is where the guides go. If its to be a casting rod guides go on the top. If its spinning the guides go on the bottom.

When I cast that rod the energy is going to load it straight and its going to cast straight."

There is no misunderstanding. He is quite clear. And I build all of my custom rods exactly according to this as described by Gary Loomis. Been doing it this way for decades.

Let's also be clear on another point. Gary Loomis said- and for those who think Gary is holding a bent rod and saying he is building on the straightest axis- let's be clear here... Gary Loomis a maker of rod blanks clearly says "if a rod is going to be bent, that 90% of the time it will be be bent towards the soft side he is clearly showing how to find.

Point is, for those who advocate that Gary is claiming he is building on the straightest axis here, in his own words he says 90% of the time this is where the bend will be. But NOT every time -and certainly not 100% of the time. And this is coming from a man who made his career making rod blanks.

He is NOT building on the straightest axis. He is building based on the softest side and he makes this very clear over and over. No misunderstanding about it.

Finding the straightest axis is not found by bending a rod. To get to that 100% every rod will have to be compared and measured against a perfect straight edge so that every single blank can be accurately examined for its straightest axis. Gary makes it perfectly clear that the soft spot and straightest axis DO NOT appear in the same location 100% of the time and he could not have cared less about straightest axis, as he said bend the rod and find the soft spot and build from there 100% of the time.

I have never built a rod on the straightest axis and honestly don't care. I build based on where that rod WANTS to bend the easiest precisely as Gary Loomis shows us and describes in great detail here in this video.

There is nothing really to debate or argue about. Quite simply there are different ideas and different methods on how to build a custom rod. To each their own. I choose to adhere to the Gary Loomis way of doing things and debating what words mean what spine up or down, or is his bent rod demonstration really all about finding the straightest axis is all really moot and irrelevant. Semantics really. Gets us no where except down the rabbit hole.

I pick up a rod. I spine it same as Gary does. And put the guides on the rod same as Gary describes it. Straightest axis, spining, splining, whatever. I want that rod to load into the soft spot because like Gary says it will be straight and cast straight and he makes this point clear and I agree with him on it. And that's it.

Truth is we mostly agree on what we are doing, and it is the words and understandings of them that trip a lot of us up over this. Gary makes that clear as well.



Edited 2 time(s). Last edit at 04/17/2021 01:49AM by Kent Griffith.

Above Kent mentioned straight casting. I read two articles on that same issue regarding spinning the rod. The article said that the rod/blank wants to bend at the spine so putting guides on the spine, either the soft or hard side, that is where the rod bends.

Kent,

The blank's softest and stiffest axis are almost never 180 degrees opposite each other. Sometimes they're close and yet other times they can be at 90 degrees to each other.

You will never load a rod on a cast to the same extent that you will when fighting a good fish. For this reason if utilizing the blank's strongest or maximum deadlift capacity is important to you (it may or may not be) then you want the straightest axis, belly down. This is typically, almost always, the blank's strongest or stiffest axis.

................

There are many people on this site who have a wealth of knowledge. I'm not one of them. I'm here only to learn and be a part of a group. While on here I've noticed butt kissing. Nobody's way of building is "the best" way. We aren't talking religion or politics here. I don't really give a rats fanny how others build on or off or sideways of the spine but I do like to research and gather info and make my own decision based on what I learn. It seems to me from the comments that the people who care most about this issue are the ones that choose not to build on the spine. I say, great for you. The only thing I really care about is that we're all learning and improving and are happy in our lives and grateful for the knowledge and opportunity to build our own rods. Enjoy!!



Edited 3 time(s). Last edit at 04/17/2021 02:04PM by Tom Kirkman.

Has anyone ever calculated the physical* versus emotional difference between building on the spine versus building on the straightest axis or building any which-way?

* something measured in feet or inches or pounds and ounces rather than "Feelings" of "smoothness" or "strength" or "accuracy"?



Edited 1 time(s). Last edit at 04/17/2021 10:18AM by Phil Ewanicki.

QUESTION for you Tom if you are still following - HOW did you attach weight to the blank tip capable of holding 20+ lbs? For UL I just attach weights using masking tape but that is not the most elegant method. I once had a blank tested by a manufacturer and they sent me photos and had some kind of rubber tube that they simply put on the blank tip and the pulling tension tightened it. I could never find that thingamajig. Thanks.


I'm not sure if anyone commented on the illuminating Rodbuilding article Tom shared.

1. I am surprised by how CONSISTENT the blanks are in breaking strength. Every single blank with the natural soft axis broke in the 22+ lbs range. Every blank in the strong axis broke in the 23+ lbs range except for one at 24.1 lbs. The data actually gives me confidence in building. I've always wondered about the consistency of break strength.

2. I build UL and notice that between dozens of the same blank, there can be a noticeable difference in power between different production batches. And building on the soft or stiff axis makes a measurable difference when fishing when using ultralight lures and jigging them. So I build more on what I need out of the power rather than the straightest axis.

3. Thanks Tom for sharing that article on breaking 50 blanks. Kudos for the effort. I am sure that took quite a bit of time as you were suspending and adding in 0.1 lbs increments - for all 50 blanks. Wow.

ps: I'm also surprised that there are 3 pages on spines after so many threads through the years. A hot topic for sure. :)



Edited 2 time(s). Last edit at 04/17/2021 01:30PM by Mo Yang.

Mo -

The only way to suspend that kind of weight from the tip is to securely mount a tiptop to each blank and hang the weight bucket from that. Now here's the interesting part - hot melt glue did the trick and not once did a tiptop slip or come loose from any rod tip under the weight amounts listed.

For the record, the blanks were from St. Croix. I had over 200 of the exact same model so that we could do these tests (see the article on rod breakage as well) with the same make and model rod blank. Otherwise the results wouldn't have been relative to each other. And yes, the quality control had to be excellent for these blanks to all possess roughly the same deadlight capacity per the respective axis. There's really no use conducting such tests on blem or junk blanks.

And finally there seems to be the idea among some that the softest and stiffest axis on a rod blank are 180 degrees opposite each other. They're not. So the idea that you can utilize one on the cast and the other to fight a fish doesn't hold water (no pun intended). You sort of have to choose your priority and go in that direction.

.............

Tom Kirkman Wrote:

> And finally there seems to be the idea among some
> that the softest and stiffest axis on a rod blank
> are 180 degrees opposite each other. They're not.
> So the idea that you can utilize one on the cast
> and the other to fight a fish doesn't hold water
> (no pun intended). You sort of have to choose your
> priority and go in that direction.
>

And likewise there is an idea that if the hard or stiff side is down that this position is the only way to fight a fish. Its not. And furthermore it is not important where the stiffest side is in relation to the softest side. In my view one is more important than the other and here I go into my direction on it... stacking the priorities and why...

I should add that this skewing effect increases with the increased length of the rod. The longer the rod, the more the side to side skewing can be. So for longer rods like fly rods spining them correctly is especially important. Shorter rods not so much.

Multi-sectional rods, spine each piece, mark them, and assemble the entire rod as one correctly spined rod for best results.



Edited 8 time(s). Last edit at 04/19/2021 10:05AM by Kent Griffith.

You may want to delve further into how Gary has oriented his blanks over the years - he has consistently said that he finds the natural curve in the blank and orients it so that the belly is down and the tip and butt are up. This is the straightest axis, not the spine. The weight of the guides are then more easily carried by that stiffest axis and tend to return the rod to somewhat straighter. His take in the video is somewhat different. Just as Dale Clemens went both ways on the matter over the years.

As far as performance, there has never been any data or tests done, to my knowledge, that show a rod built on or opposite the spine to outperform a rod built on any other axis. Nor does spine orientation prohibit blank twist under load. We know that for a fact.

The article I linked to in the library simply shows that if you want the maximum deadlift capability from your rod blank for use in fighting a fish, you'll want to build on the straightest axis, belly down, tip and butt up.

None of this is intended to prove that one way or the other is better. It is simply a matter of providing data from actual tests (not theory) and providing that data to the rod builders so they can determine if the information is something they can use in their rod building endeavors. The conclusions drawn from the article were intended to confront the idea that rods built off-spine would somehow be less durable, less strong or fail sooner than rods built on spine. Here is the conclusion from that article:

Conclusion
The two blank groups in our tests exhibited less than a 6% difference in typical deadlift capacity. Additional tests with other blank models would be required before we could state that this figure would be true across the board for all blank models and types. It may not be, although it is almost certain that some difference would be recorded in all cases.

From a purely technical standpoint, it is therefore reasonable to state that a rod built on stiffest/straightest axis has a greater deadlift capacity than a rod built on the effective spine. The idea that rods built off-spine will fail sooner than rods built on the spine is incorrect. In fact, exactly the opposite is true. Having the cumulative thicker wall predominantly on the compression side of any blank flex results in greater lifting capacity before failure.

So does the slight difference between having the stiffest or softest axis on the compression side make any practical difference to the rod builder or angler? Considering that few styles of fishing allow for casting and fighting on a single axis, any great concern over blank orientation would appear unwarranted. However, the reader is left to draw his or her own conclusions as needed for their personal requirements.

.............

Tom Kirkman Wrote:

> As far as performance, there has never been any
> data or tests done, to my knowledge, that show a
> rod built on or opposite the spine to outperform a
> rod built on any other axis. Nor does spine
> orientation prohibit blank twist under load. We
> know that for a fact.
>

This is an interesting point to consider since a rod is loaded twice differently. Once in the backswing of a cast, and secondly when a fish is on.

It seems to me that when a rod loads up in the backswing, if there is any twisting effect caused by any guides that it is not a detrimental twist, but can in fact unload in the forward swing and add extra propelling force forward to enhance the cast.

In other words, the cast is enhanced not only from the rebound of a loaded rod in the backswing, but can also receive some added boost from the throwback twisting effect also unloading into the forward swing. So I don't see it as detrimental in the cast.

And since I use only spinning rods, and Cagey Hook Wrapped rods or spiral wrapped, both with micro guides, twisting is not an issue to me when a fish is on, and I doubt I really get any benefit from a backswing twist in the cast either since the guides are so short the line flow is almost directly on the blank anyway.

But it is interesting to consider.

Tom Kirkman Wrote:

> The article I linked to in the library simply
> shows that if you want the maximum deadlift
> capability from your rod blank for use in fighting
> a fish, you'll want to build on the straightest
> axis, belly down, tip and butt up.
>

Yes sir, and this is not something I really want or need or care about. I might think differently if I were building rods for 8 foot long sharks, or huge marlin, but for bass fishing, snook, redfish, etc. 6% is not enough to make much difference to me, and I'm far more concerned about where the soft spot is for casting predictability and this is what Gary was explaining and demonstrating as well and I just wanted to expand on it since this issue of spine keeps coming up and discussion is all over the place while pure physics never changes.

Like you said, each person has to choose for themselves what is their priority and which direction to go in.

Tom Kirkman Wrote:
-------------------------------------------------------

> The idea that rods built off-spine will fail
> sooner than rods built on the spine is incorrect.
> In fact, exactly the opposite is true. Having the
> cumulative thicker wall predominantly on the
> compression side of any blank flex results in
> greater lifting capacity before failure.
>

This is also not an issue for me. I don't go around breaking rods on a regular basis. I still use rods that are 30 plus years old and still like new.

But to your point, placing the soft spot up every time is basically the same as saying the thinnest portion of the rod is also up, and the thicker sides are below it. This would tend to follow your explanation of having the thicker wall predominantly on the compression side.

So doing it how Gary Loomis described and demonstrated is right in line with this.



Edited 2 time(s). Last edit at 04/17/2021 03:43PM by Kent Griffith.

Just remember that if you were blindfolded and a rod was spined according to the way you and Gary do it and another identical rod was built on the straightest axis it would be impossible to tell them apart since the performance would be identical the only difference is the one built on the straightest axis will appear straighter than the other when sighting down the blank & one will have slightly more lifting power.


Building according to the spine has absolutely nothing to do with accuracy or performance . The only possible way building according to the spine might be favorable is if you were able to fish a rod on the exact same plane as the spine which never happens.

Gary Loomis is very old school and a genius rod designer but just one man , he's a master of manufacturing rod blanks but his expertise pales by comparison and isn't anywhere remotely close to the experience Tom has when it comes to over half a century of testing, evaluating & documenting rod guide layout's , rod setup's & performance differences with countless best selling books on the subject and the world's # 1 rod building magazine . Gary even uses Tom's article on rod breakage on his NFC site . When Tom Kirkman speaks the entire rod building world listens , some people just don't realize how fortunate they're to have access to the worlds leading rod building expert .



Edited 1 time(s). Last edit at 04/17/2021 03:54PM by chris c nash.

chris c nash Wrote:
-------------------------------------------------------
> Just remember that if you were blindfolded and a
> rod was spined according to the way you and Gary
> do it and another identical rod was built on the
> straightest axis it would be impossible to tell
> them apart since the performance would be
> identical the only difference is the one built on
> the straightest axis will appear straighter than
> the other when sighting down the blank & one will
> have slightly more lifting power.
>

It might be impossible to tell them apart just looking at them, but if one rod flows into the sweet spot on the backswing and the other one does not and you can feel it, then you just may be able to tell them apart.

As to your description of a rod "looking" straight, that don't catch fish. And the fish don't care if the rod is straight or not. That is for rod sales more than anything else.

As to your point on having ever so slightly more lifting power... so what? If the soft spot is up, that can only mean the harder or stiffer sides are down under where they also give more lifting power, but just maybe not as much as if the stiffest side were placed on the bottom just for lifting power while casting predictability and ease of operation are thrown out the window.

Doing it how Gary described in the video does in fact put greater lifting power on the compression side.

chris c nash Wrote:
-------------------------------------------------------
>
> Building according to the spine has absolutely
> nothing to do with accuracy or performance . The
> only possible way building according to the spine
> might be favorable is if you were able to fish a
> rod on the exact same plane as the spine which
> never happens.
>

Nothing to do with accuracy or performance? So Gary Loomis was not telling the truth as he described where to put the soft spot and why and then declare how important that was to straight into the backswing and straight out of it? I'd say that was clearly performance related so let's agree to disagree. Spining is done for purely this reason alone. Always has been and always will be until they can build a rod with no spine.

Your last point can not be quantified without limiting factors like define spine and what direction of spine are you referencing to make that statement? This is what got me started on this thread in the first place when Tom said something about lift and spine without directional references.



> Gary Loomis is very old school and a genius rod
> designer but just one man , he doesn't have
> anywhere close to the experience Tom has when it
> comes to over half a century of testing,
> evaluating & documenting rod performance with
> countless best selling books on the subject and
> the world's # 1 rod building magazine . Gary even
> uses Tom's article on rod breakage on his NFC site
> . When Tom Kirkman speaks the entire rod building
> world listens , some people just don't realize
> how fortunate they're to have access to the worlds
> leading rod building expert .

We realize! Just some of us like a challenge and to push it some! Tom gets it!

Differences are what makes the world go round! If we were all the same this would be one boring place!

Speaking of which... gotta hook up the boat and run. Its fishing time. Time to put some of this techno mumbo jumbo to good use.



Edited 1 time(s). Last edit at 04/17/2021 03:57PM by Kent Griffith.

Chris,

Thanks but I don't consider myself the world's leading rod building expert. Lots of knowledgeable builders out and about.

...............

Kent, I grew up building rods before Clemens or Pheiffer ever spoke about rod spine. I have always built on the straightest axis and my rods have never exhibited any of the stuff you diagrammed. And they cast predictably ---- the lure goes exactly where I cast it. When it goes into a tree it is not because I built off the spine...

No matter what Tom says, and I do not doubt his opinion whatsoever, and whatever we might believe, you will not see any factory or instructional video that does not show how to spine/spline a blank. They simply believe the process is important to what their customers have been led to expect is proper rod construction. Eyewash. It will be an ongoing issue long after my ashes are broadcast over the lake. You can't fix stupid.



Edited 1 time(s). Last edit at 04/17/2021 07:34PM by Lynn Behler.