"Missing" the spine

[JasonGotaProblem]

I was in the store looking at rods this weekend. These were not super fancy ones. Or fancy at all really, all were under 50. I tend to test actions by grabbing a rod with 2 fingers, just below the tip and pulling down. What was interesting is that when you do so, some rods tend to wanna twist in hand while bent, others don't. One actually turned about 120 degrees in my hand when doing so. I went home and tried this on some of my slightly nicer rods, and they didn't twist. Is this a sign that the makers of the ones I looked at in the store failed to line the hardware up with the spine on the blank?
Furthermore how does one properly locate/identify the "spine" on a blank?

[thrasher]

I put the butt on the ground and lay the tip on my right fingers, with my left hand I put a flex in the rod and spin it a bit with my right hand.  It should snap back to it's natural bend.

It wouldn't surprise me if cheaper rods don't find the spine at all but it's so simple to do I don't understand not doing it. I've even heard people say it doesn't matter but I always do it

[Midway Tommy]

It does matter but you set the spline different (just the opposite) for spinning or casting configurations. There are plenty of examples on YouTube showing how to determine and place the spline. Most makers of cheap rods do not take the time to find and position the spline. Also, it is near impossible to locate a spline once the guides, and especially the handle are intact. The handle will usually keep it from rolling into the correct position.  

[oldmanjoe]

 Just add to Tom`s post  if it is a 2 piece pull it apart and check , the top section is heart  of the stick.
  I like to hold the stick  at the front grip and thump the bottom of the stick just ahead of the front grip.
There is a harmonic vibration that i look for .   When you go through the rack of the same  stick you feel one that is just rite or the best of the bunch.

[JasonGotaProblem]

Interesting stuff. So am I correct in thinking that where the blank rolls to is the spine? Or is that natural point 180° away from the actual spine? That may be a dumb question but I'm trying to grasp the concept.

I have a cheapo rod that no longer gets used as the quality of my collection has increased. I always noticed the rod bent a bit to the left on an otherwise straight cast. I'm now thinking its related.

I guess to clarify the question, the spine defines the natural bend direction, or the opposite of it?

[thrasher]

Wrap a piece of masking tape around the blank, bend and find spine and mark it on the tape. Align reel seat and guides along that line for a spinning rod and 180 of the mark for a conventional.

[philaroman]

what about an old Conolon (Live Fiber?)...  sloppy practice build -- not, restoration
looking for excuses to keep original brass ferrule as is (otherwise, stripped blank)
would the small male half interfere w/ sp[L?]ining the tip section, significantly?
should I roll on table edge, so only blank right above ferrule makes contact & brass is in the air?

[Ron Jones]

Interesting stuff. So am I correct in thinking that where the blank rolls to is the spine? Or is that natural point 180° away from the actual spine? That may be a dumb question but I'm trying to grasp the concept.

I have a cheapo rod that no longer gets used as the quality of my collection has increased. I always noticed the rod bent a bit to the left on an otherwise straight cast. I'm now thinking its related.

I guess to clarify the question, the spine defines the natural bend direction, or the opposite of it?

The spine always goes on the bottom. For a spinner, the eyes and seat are aligned with the spine, for a conventionally wrapped conventional (see what I did there?) the eyes and seat are 180 degrees from the spline.

As posted above, once a rod is wrapped there are things that muddy the waters and makes it very hard. The rods you were messing with may have a flat spot on the but or a hard line through a cork grip that may imact how the rod rolls more than the spine.

Ronald Jones

Ronald Jones

[oldmanjoe]

 Lets see if this helps ,  pictures of two different rod tops . first picture is the top section at rest .    the second picture is pushing down in the middle and the spline is on the bottom , and the guides are 90 degrees from the spline .
  Third picture is another top section , bent  ,  spine on the bottom and the guides are 180 degrees  .  Some spines are more pronounced than others , when i push on the middle the guides pop up with no trouble.      These were the best 2 of about 15 stick on clearance for 15 bucks, Tsunami shock waves.

[Jeri]

A lot of wisdom about spine of blanks is not always correct, and the way I have found to explain this to clients is as follows:

Imagine a piece of paper wrapped around a pencil, exactly 5 times, such that everywhere except the very point of precise overlap has 5 layers of paper. At the point of overlap there are 6 layers - this is the spine. So, because it has 6 layers it is marginally stiffer in that exact plane than the rest of the blank. So, having determined the spine of a blank with the rolling method, you are actually finding the point opposite to the stiff/spine side. Having marked this, you now have decisions to make. #

There is conventional wisdom about spine position on spinning and conventional rods, but the opposite is equally true and valid, depending on the exact action desired by the client. Back in the days when my wife and I did line class boat fishing, she would prefer a slightly softer action to the rod, while on the same blank I would prefer a slightly stiffer action, and as such we would build both rods on opposite sides of the spine.

In surf rods for clients, I have often found that using the soft side as the favoured side during the loading phase, allows less powerful anglers to get more power into the rod, because it is slightly softer, while more powerful people can load the rod easily with the spine on the harder side.

Basically, at the end of the day, any blank can be built in just 2 positions, and 358 degrees of wrong positions. A classic case was a client that came in to have 6 client rods refurbished, and one was marked with red electricians tape around the handle - with a note saying this one was 'his', as it was so 'sweet' to cast. On stripping all the rods down and checking, just that 1 out of the 6 had been built either of the 2 planes of the spine, the others were all over the place. Phoned him up and asked if he wanted the other 5 corrected with new reel seats, and now he has 6 'sweet' rods.

[Dominick]

Great explanation Jeri.  I like that paper and pencil analogy.  Dominick

[jurelometer]

Here is a very old video of a very young Gary Loomis.  A good demo of spine finding at the beginning.



A couple more personal observations from my limited experience::

1. On a multi-piece blank, spine each  piece separately, and then spine the whole assembled blank withe the individual spines aligned.  If the spine moved, starting with just the top two pieces assembled, rotate the bottom pice until the assembled spine aligns with the top piece spine.  Repeat for remaining sections.  This will favor the tip section, and therefore the casting (vs. fish fighting)  effect of spine alignment..

2. On  thin walled, light whippy blanks (like fly blanks), there is often a secondary spine, so it can get confusing.  Just choose the more dominant spine.

3.  For some applications the spine can really matter, especially if it is prominent enough.  Jeri's surfacasters sound like one good example.   For most general purpose freshwater  usage, not so much.   Think about how often  you are casting /flipping, or playing  a fish with the line off angle from the centerline of guide placement.  

It does not cost much to spine a blank  properly, and the process could easily be automated, so if it made a big enough difference, spine aligning would be a more common practice on factory rods.  

But in the end, it never hurts to build on the spine, so why not?

4. The older, cheaper, or  heavier/stiffer the blank, the more likely it  will have  a more prominent spine.

5. A fun science experiment would be to test with a scale, and see how much the load actually differed bent on both sides of the spine and 90 degrees using both light casting and full useful load (90 degree bend), and then repeat after adding guides in the proper spined location.  Just requires a flat smooth surface, a c-clamp, masking tape, sharpie, and a pull scale.

---
Regarding the question of spine finding with a stamped brass male ferrule:

Some of those old ferrules are not exactly round, so it might be a bit more difficult to find the spine.   Your plan of using a table edge to avoid the ferrule seems like a good idea to me.

-J

[JasonGotaProblem]

This is turning into a great thread, and I'm learning a lot. As usual.

Out of curiosity I went and googled the rod that was the biggest offender. And I was surprised to find its an $80 rod!  So there were a bunch of $30 rods on the rack that got it right. But the $80 one got it wrong. And now I'm annoyed.

Would there be any benefit to having the 2 spines of a 2 piece rod 180° apart from each other?

[oldmanjoe]

       Next time you are in isle 4 , take the top of one stick and try it base of the other stick .     You can build a rod before you buy it !!!

[Midway Tommy]

A decade or two ago there were some that thought if you put the guides on a spinning blank on the convex side it would eventually straighten the rod out. That will never happen with a graphite blank because of the way the sheets are wrapped on the mandrel. I tried that concept on a couple of my first builds. They were fairly light compared to many rods out there, 6-12# sticks. I hated the way they acted. They always wanted to twist with a light load and they never straightened out. I have since then built all my under reel rods with the guides on the inner/concave side.