One thing that continues to be misrepresented here, is that the blank wants to bend along a particular axis. That is not true. It doesn’t want to bend. If you bend it and release it it will come back to straight. It does not want to bend that’s why it will function as a fishing rod. It is the resistance to being bent or flexed that makes it work. So this idea that you want it to band along the softest axis doesn’t make sense. You want it to resist bending as much as possible and I believe this is why the data shows that the straightest axis gives you the greatest lifting strength that the blank can offer.



Edited 1 time(s). Last edit at 09/09/2020 08:46AM by Mike Ballard.

Mike Ballard Wrote:
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> You want it to resist bending as much as
> possible and I believe this is why the data shows
> that the straightest axis gives you the greatest
> lifting strength that the blank can offer.


I get it now... at first I was not correlating straight to spin orientation lingo, but now I am up to speed on it, but still a little unsure, but I will keep reading and take it all in and see if I can come around to this new way...



Edited 2 time(s). Last edit at 09/10/2020 08:39AM by Kent Griffith.

The data indeed shows that rods built on the spine will fail under less load than rods built on the straightest axis. The article and test data was provided earlier in this thread. And the reason is quite simple. It has to do with the fact that carbon rod blanks, when loaded to failure, will fail on the bottom first, with a resulting collapse of the entire structure. Using the straightest axis, with any curve placed so the butt and tip are "up" and the belly is "low" puts the thickest cross section of the tube on the bottom. This is why rods built in this fashion will withstand greater load before failure. Their deadlift capacity will be greater when built in the orientation.

...........

Thanks! Reviewing it now. I agree with that, but not the "straight" claim. Straight does not control nor affect lift capability was my point, but I see now the use of the term "straight" also carries with it other implied meanings I was not previously aware of until now... trying to get up to speed.

I do find this quote matches my comment opinion:

"When a rod blank is oriented in such a way that the majority of the thickest wall is on the compression side of the flex, the blank will exhibit its maximum deadlift capacity. When the blank is oriented so that the majority of the thinnest wall is on the compression side of the flex, the blank will exhibit it's minimum deadlift capability."

So being straight does not affect lift capability I gather. Spine does from what I am reading...

Where I went wrong is in assuming the reverse of the "soft" side was 180 degrees opposite. The articles says this is rarely the case. I found that most interesting as well as the following conclusion:

"The idea that rods built off-spine will fail sooner than rods built on the spine is incorrect. In fact, 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."

It makes sense that forcing the bend towards the thickest section or strongest section of the rod blank will cause to want to come apart more readily than if going with the easiest bend point in the thinnest section.

I can see where this would matter more to saltwater rods which are put under greater stresses than I ever see in my bass fishing rods. It is not as much of an issue there.



Edited 3 time(s). Last edit at 09/10/2020 08:43AM by Kent Griffith.

You will find that the straightest axis is generally in line with the thickest cross section of the blank. Try it for yourself and I think you'll agree.

It should also be noted that building on the spine, while it will result in slightly less deadlift strength, does not necessary create a "weak" rod. It simply doesn't put the blank's maximum capacity in play when fighting a fish.

...........

Kent G- I agree.

I set up the guide train and reel seat location as follows; I permanently attach the rear grip (orientation is cosmetic and not critical) I check for the straight axis and locate the spine. The reel seat is installed (in line with the straight axis) and taped to the rear grip. The guides are taped on to the blank and the tip is taped in place.

The reel is mounted and I take the rod out and work it, checking for accuracy in casting and distance, I make any adjustments to the guides and/or reel seat until the rod functions effortlessly. I actually fish with it and if I am satisfied with the results I record and mark the location of all the components and prepare for the final assembly.

At this point the position of the guides relative the position of the spine is what it is.

YES, YES, it is tedious, time consuming, aggravating and certainly not practical for mass production, However it is my best assurance that the rod will perform and "feel right" after final assembly.

I have always struggled with the concept that there is never enough time to do a job the first time but there is always time to do it over.

Bottom line from experience location of the straight axis and the spine are usually close enough not to pose an issue and guide placement is a matter of personal choice.

i recall about seventy years ago going down to the creek and cutting off a tree branch, tying a white string on the thin end, tying on a hook and stabbing on a worm..wading out into the creek and swinging the worm around and hitting spots exactly along the bank catching what ever..that branch-rod had twists and bends in it but nothing bothered my accuracy..like Tom said, the cast goes in the direction the tip goes..lol.

Its called being taught by doing an expensive course under the tutelage of a very experienced rod builder
Much like anything really
But thanks for questioning an angler with 40 years experience anyway

Do NOT tell me what I felt and carefully tested (for several days across multiple rods) with my hands is wrong
Some unspined rods are absolutely HORRIBLE and torque twisty to use
= FACT

I believe the rod should always be built with the guides aligned in the plane of least resistance
And I mean the WHOLE rod, not just the top section
Its the whole rod you use, after all, not just the tip!

You are trying to tell me my judgement, hands, and feel are wrong
And you hae no idea how many hours I spent testing different rods
My eyes, hands, and experience do not lie!
You obviously work for a major manufacturer and are happy to repeatedly spout rubbish about how the spine doesn't matter
IT DOES, and you have met your match mate because you talk generalistic rubbish on a daily basis

Fantastic post. Thankyou for talking above this crowd of sheep.
I PM'd you mate

It is far from being that simple
And by ''far'' I mean you are hundreds of miles off
You are just believeing rubbish that has been fed to you and have obviously not studied the subject for yourself in any way or don't know how to

Professionally trained means that I spent a lot of money learning from a very experianced rod builder
What is the problem people have with that!?
Good point re: strong spines versus weak ones
Obviously a strong spined rod must be built with the utmost care and a weak spined one can be built however you choose
I would have got to that had people on my thread, in general, not been so defensive about the reactionary rubbish they spout and quick to try and condemn a topic that goes back absolutely decades and has been systematically rubbished time after time
The fact is that I would have to be paid myself to use MOST rods in circulation rather than test them first or (God forbid) pay for them!!!!!!!

It seems the reply function here is a bit odd
I expected it to quote the message I was replying to!? (That would seem fairly logical)!!?

Let me help you people

The non spine built rod with strong spine I tested twisted HORRIBLY, OBVIOUSLY and REVOLTINGLY under load
My hands and eyes do not lie!!

It was a short spinning rod
The spine gets more and more important the shorter the rod is
And the spine itself is of MASSIVE importance to the FEEL of the rod
I don't want to play fish sideways, I want the FEEL going straight down to my hand!!
This is not about physics, it is about FEEL (although I am not sure a scientist can tell a fisherman of 40 years experience what is right and what is not)!!!

As much as I am fascinated by vague, undocumented claims by people who refuse to reveal their test procedures and test results [if any] to prove their claims I think I'll continue to build blanks on their straightest axis. Still, I would switch in an instant if anyone revealed actual, measured test results proving rods built on the spine perform better. I don't put any faith in undocumented hearsay - a strategy which has served me well over a long life.

"Feel" is subjective. Numbers aren't.

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

WOW! Egos are are being ruffled.

When sharing ideas or passing on information I really don't think brandishing ones qualifications to drive a point home is necessary, if what is said is factual and accurate no other validation is necessary.

I am not impressed and I become wary when someone tells me they have 40 years of experience, There is a big difference in truly having 40 years of experience or repeating your first year 40 times.

I have offered my input and I have read all the responses, now it is up to me to decide based on my experience, experience of others and whatever empirical data is available which is the best solution for me.

There are a lot of folks out there with 40+ years of experience and some can rival many "Professional Rod Builders" but are too modest to mention it.

I place myself in the class with the guy on the Farmers Insurance commercial "I seen a lot and done a lot"

"RUMP BARUMP BOMP BOMP BAR RUMP"

In conclusion, I start my build along the straight axis and adjust from there.

This topic is one of the things in Rod Building as other things are in other situations.

But, without a doubt - if you wish to build on the spine, build on the spine of the blank.

But, if you want to build on the straightest axis, then build on the straightest axis.

Or, If you don't care about the spine nor about the straightest axis, just plunk down the rod blank and build it on which ever side you wish.

I suspect that at the end of the day, all three methods will do a wonderful job of catching fish.

Best wishes.

i can handle almost any flaw in a rods construction but looking down a rod and seeing it curve to one side or the other makes me ill..it,s just got to be built on the straightest axis..i couldn,t care less about spine..it,s just a lot of clap-trap..and boy this hobby has a lot of that for some reason..