The trouble with reading through the forums on this topic is that no proper solid explanation is given as to what ''spine'' we are talking about

Please let's sort out what it is we are actually discussing!

Let's talk about a standard tip section from a freshly cut blank, as on these sections the spine is very apparent as opposed to the thicker butt section where not only is the spine harder to feel but also probably matters less:

When you roll a blank in your hands, tip up, with the base of the section on a flat smooth hard surface, you feel two or three obvious things: A (sometimes) very sharp, pronounced ''bump'' or hard spot that the rod is desperate to roll away from (this point obviously being the thickest and strongest part of the blank)..

Then there is often another ''bump'', this being a second spine, but far less pronounced and obvious than the first

Then there is a ''flat spot'' where the rod likes to settle comfortably and also bend more easily, and maybe, again, another less obvious one..

Ok so now the bit where things get confused communication wise between individuals and (especially) nationalities..!

In the UK (generally) we would (or may if we were a custom builder and thinking that we were getting ''one up'' on mass produced rods), find the hard, pronounced, dominant ''bump'', call THAT the ''SPINE'' and put the guides UNDERNEATH that. The thinking being that that is the part of the rod that will be taking most of the strain of the rod's working life, and taking the brunt of playing hard fighting fish. That is the side of the rod that will be getting BOTH COMPRESSED AND ELONGATED, while the side with the guides on is being COMPRESSED ONLY

I don't want to get into talking about different styles and reel use, please imagine for arguments sake that I am talking about sitting by a lake static bait ledgering using a fixed spool reel UNDERNEATH the rod

The SPINE that seems to be discussed on American forums like this and by golf firms is not in my opinion actually the spine, it being the point of easiest flex and settlement, i.e the weakspot of the blank where twist issues would be least

You can see how this topic can be confusing enough without people discussing an entirely different ''thing'' or concept in the first place
So please can we ''tidy this up'' after all so that people may start really understanding the subject and be able to make an informed choice as to what we are actually banging on about















Over to you



Edited 3 time(s). Last edit at 07/29/2017 05:36AM by Tommy Bee.

"Let's talk about a standard tip section from a freshly cut blank, as on these sections the spine is very apparent as opposed to the thicker butt section where not only is the spine harder to feel but also probably matters less:"

Whether the handle section matters less or not is really a matter of the power of the caster vs the power of the rod. I have a 14' tournament rod that has a fast action. To spine the handle, two soft bound books are placed of the floor about 5 feet apart and the handle is placed across the books. Your hands go on the blank and then your knees go on your hands. It is an easy and fast method. A friend is a very powerful caster and although the blank is fast action, when he casts it is almost a perfect C curve. A UK caster inquired about this same matter. After he adjusted his rod, he reported more comfortable casting with less cause to fight handle twist and greater casting distances. These casts are usually low reel with a multiplier.

<Edit - The above technique should only be used on a powerful blank with a parallel handle. These blanks often employ a spigot.>

Don Becker



Edited 1 time(s). Last edit at 07/29/2017 07:13PM by Donald Becker.

Yes fine more spine opinions, ok,

but more to the (whole) point of the thread:

What exactly are you talking about being the ''spine''?????

i don,t know and the more it,s talked about the less i know....i rscall Tom Kirkman saying it was not a thing and that it was an effect. so far that makes the most sense to me.

Many times when you you spine a rod you will feel the rod 'jump' in two different locations, and these locations are usually not a180 degrees apart. Does this mean that the rod has two stiff spots? Are these double spined rods a problem? To me the answer is no! I have built thousands of rods over the past 47 years and have come to believe that the importance of the rod spine is a myth. I now build on the straightest axis and have never had any casting or fish fighting problems. Some will agree with me and others, like yourself, will not, so discussion about the rod spine will continue. My advice to you is to do it the way you want to, because it will make little to no difference in rod performance. Many people who do spine their rods like to put the soft side (concave side of the bend) of the rod towards the fish. If you have a double spined rod you just have to figure out where the soft side is located.
Norm

Maybe we can next discuss the number of angels that can dance on the head of a pin?

More seriously, when I "spine" a rod or rod section I am not concerned with the "bumps". My mission is to find the softest "flat spot" on which axis the guides for a fly or spinning rod might be mounted. The spine is thus assumed by personal definition to be opposite the softest "flat spot" regardless of whether or not the most pronounced "bump" is 180 degrees opposite the softest "flat spot".

Now, about the angels and pin thing . . .

Angels are big, so:

none

Spine has nothing to do with rod twist. Guide orientation dictates if a rod will twist under load or not.

You find some value in this: [www.rodbuilding.org]

..........

I would bet that in a double-blind experiment no angler could reliably distinguish whether or not a rod was built on the spine. However, fishing is an activity founded in faith, hope, and trust - even superstition! If building on or off the spine or imagining you are doing so increases your satisfaction and confidence why not do it?

i was wondering, with the new high pressure blank roller machines is the spine effect as strong as it used to be or is the jump as strong as it used to be in todays blanks.

I think with modern rods the spine is slightly less obvious
I just got some nice old glass blanks and the ''bump'' in the tip section is very pronounced

But people are still missing the point of this thread

It is to establish exactly what people are talking about when they refer to the ''spine''

In my understanding the 'bump's one feel when spinning a blank are the edges of the carbon fibre cloth. The more distinct one must be the straight initial edge of the prepreg from which it is adhered to mandrel and the second must be the 'end' of the prepreg. I my understanding the plane of the 'spine' would change if one cuts the section shorter as carbon fibre blanks are manufactured the way they are. Has anyone done this?

I also hesitant to believe that the 'spine' (meaning the stiffest plane of the blank) is where the most distinct bump is because right by this seam there is one round less material. The actual strongest point of the blank must the somewhere near this point in relation to where the end of the prepreg happened to end and the effect of the whole structure. Any thoughts?

Cheers!

-Miki-

In the U.S., most refer to the "effective spine" as the point where the blank will come to rest and want to stay, when pressured.

Spine is a not physical thing but an effect caused by various manufacturing anomalies. The edge of the prepeg pattern does not run along a single axis - it tends to spiral along the length of the blank. Sanding is another aspect that can contribute to the effect. Blank warp or curvature also contributes. But the lever arm effect of the guides will always overcome any spine effect.

But we don't have these conversations as often as builders did 20 years ago. Many, if not most, disregard spine and build on the straightest axis.

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

Tom Kirkman Wrote:
-------------------------------------------------------
> Spine has nothing to do with rod twist. Guide
> orientation dictates if a rod will twist under
> load or not.
>
> ..........


Please explain what causes rod twist when you cast a conventional and the guides follow the rod during the cast.

Don Becker

Two of the more accurate bits of information:

" If you have a double spined rod you just have to figure out where the soft side is located."
"The spine is thus assumed by personal definition to be opposite the softest "flat spot" regardless of whether or not the most pronounced "bump" is 180 degrees opposite the softest "flat spot".

Generally:
I find the softest spine and use it for reference.
There is usually a secondary spine about 180 degrees from the primary spine. Most are in the 175 to 185 degrees from the primary. Extremes can be as much as 135 to 225 degrees.

For more powerful rods, you will want to check the spine more deeply into the blank. This means you want to support the tip section perhaps 18 inches down the tip and provide pressure at a lower point.

A question about fiberglass rods came up. Rod twist causes the fiberglass transverse fibers to break. This in turns decreases the circular strength of the blank and allows it to go oval. I had a composite commercially made rod turn into a noodle in less than a year of use. This was not due to the breakage of the co-linear graphite or glass.

Don Becker

Donald Becker Wrote:
-------------------------------------------------------
> Tom Kirkman Wrote:
> --------------------------------------------------
> -----
> > Spine has nothing to do with rod twist. Guide
> > orientation dictates if a rod will twist under
> > load or not.
> >
> > ..........
>
>
> Please explain what causes rod twist when you cast
> a conventional and the guides follow the rod
> during the cast.

..........

The guides are lever arms.

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

Tom is correct. For a casting rod, guide orientation has more importance on whether or not the rod will twist under load than the spine. Read this article from the the library. [www.rodbuilding.org]
With the guides on top, the rod will twist no matter if the spine of the rod is on the top, bottom left or right, the lever action of the guides cause this to happen. If the guides are on the bottom of the rod, the rod with not torque no matter where the spine is located.
Norm

Mr Kirkman - How can the 'inner' edge of the prepreg (from which it has been adhered to the mandrel as a starting point for turning) spiral if it has been adhered straight to the mandrel? Very difficult to sand the inside of the blank as well to fully eliminate the edge - or atleast have never heard of any company doing this? I am not trying to be a smart ass here, just a very interesting topic.

I naturally understand that the outer edge of the prepreg does not run along a single axis. I wonder is any companies apply a sort of a one extra turn of prepreg to sand it down a certain amount?

Cheers!

-Miki-

Tom Kirkman Wrote:
-------------------------------------------------------
> Donald Becker Wrote:
> --------------------------------------------------
> -----
> > Tom Kirkman Wrote:
> >
> --------------------------------------------------
>
> > -----
> > > Spine has nothing to do with rod twist. Guide
> > > orientation dictates if a rod will twist
> under
> > > load or not.
> > >
> > > ..........
> >
> >
> > Please explain what causes rod twist when you
> cast
> > a conventional and the guides follow the rod
> > during the cast.
>
> ..........
>
> The guides are lever arms.
>
> ............

OK, I will restate.

"Please explain what causes rod twist when you cast a conventional and the guides follow the rod during the cast."

Please explain what causes rod twist when you CAST a CONVENTIONAL (guides mounted on top of rod and the reel is a LP, bait caster, or other conventional style reel) and the guides follow the rod during the cast (meaning the guides are in line and following the motion of the rod, IOW the guides do NOT precede the rod.).

Don Becker

Don,
Don - I did read your comment, and I personally feel that the spine of the rod has little effect on casting or fish fighting performance. For example, Do you always cast in one plane? Maybe if you are a distance caster, but it in most cases fishermen cast in may different planes. in addition, some cast with reel positioned up, others with the reel positioned to the side, and this can change depending on the type of cast you want to make. I used to build using the spine and still do if the blank is straight, but in many cases the spine does not define the straightest axis. I do not like the rod tip veering off to the left or right so I started building on the straightest axis, and found no difference in the way the rod performed whether it was on spine or off spine. However, in your fishing situation if you believe the spine is important then by all means use the spine. I am not saying what you are doing is wrong, nor advocating for you to change anything you are doing, I just feel that the importance of the spine is overstated and questionable. Hope this clears up my comments, I am not giving any disrespect just my opinion based on my experiences.
Norm