It should be noted that not everyone agrees with the importance of spine.
It surprises me that so many people say finding it is of utmost importance but can't agree on where to put the guides in relation to it. Some say on it, some say 180' to it and others say at 90' to it. Can they all be correct?
Many people, including many major rod manufacturers say it doesn't make any difference, This is what Dr Steve Harrison of Harrison blanks says about it
"Spines.
Ok, back to spines, excuse the pun.......... First, what is the spine?
Rod blanks are made by rolling a pattern around a mandrel. Like a swiss roll, there is a start and an end to the "roll" and they can produce a hard and soft side to the blank. That is, if you roll the blank whist slightly bent, there can be a feeling of almost a bump in stiffness in one part of the blank. If you hold the tip in one hand and twist with the other, whilst keeping the rod bent, you are most likely to feel this. Holding the rod tip against a wall or floor whilst rolling the rod will do the same. Often the spine coincides with a slight bend in the blank, as ths spine tends to pull a slight curve during the cure. Many builders would say find the stiffest side of the blank, mark it and put the rings in relation to it. But they dont agree where! Some say at 180 degrees to the spine, some say at 90. One going for the stiffest plane, one for the preffered plane of bending. There are arguments for both. I have listened to all the arguments, spent more time thinking about them than most, and I feel I have as good knowledge of the subject as anyone, but I cannot offer you a simple answer. But I do say the following, and this I know is right. Instead of twisting the flexed rod bent over a hand or some other artificial fulcrum, you hold the rod at the handle end, with a weight hanging from the other. That is you load the rod at the tip and hold it at the butt like you do when fishing. Now roll the rod through 360 degrees, and voila, the sensation of the spine has disappeared. Yes, if you do this in a special jig you will detect a tiny variation in the apparent test curve due to a spine, but it is so small you will not detect it in real life. The spine as many rod builders detect it is an artefact of an artificial test. But like a lot of rodbuilding questions, there are no strightforward answers, so talk to someone else about the spine. However, if you want my advice, for what it is worth! Put the blank together and rotate and adjust the sections until the rod is as straight as possible, any natural curve in the rod bending upwards, then place the rings on the underside."
Rod manufacturers such as Sage and Winston follow the above advice. I find it hard to believe that these manufacturers don't know about spine and given the work that goes into making the rods can it be that they just cant be bothered to spend 30 seconds checking for the spine. No, I am sure they think that it doesn't matter.
Lastly Tom Kirkman, top American custom rod builder, writer of many books on the subject and owner / editor of rod builder magazine has also stated that spine makes no real difference and that you should build on the straightest axis.
Tin hat donned
Over to you
