I have had some discussions with others about topics ranging from sprial wrapping to building on the spine. I'm surprised, to put it politely, by some of the remarks.

Has anyone had a rod failure from torsional forces? If so, do you think where the guides were located relative to the spine had any bearing? Tom, in your recent destructive testing were any blanks subjected to torsional forces?

I have never had a rod fail from torsional forces and any rod the failed in the top 1/3 or so was from an impact. I think casting with a conventional reel amounts to more (dangerous type) torsional forces than fishing fighting.

The spine plays no role in torsion or twist. If the guides are on top of the rod, it will attempt to twist, or will twist, if it is loaded from below (a fish or snag). If the guides are on the bottom of the rod, there will be no twist (unless the load is coming from somewhere other than the water). This remains true no matter where you put the guides relative to the spine.

One of the breakage scenarios we performed was to simply twist rods a full 180 degrees full length. In other words, the same thing that could happen if you were in a fishing situation and managed to have the rod twist a full 180 degrees. Not a single rod broke. Nor could we confirm any damage - subsequent overload tests showed that those rods that had been twisted broke under the same load as those that had not been subjected to twist. And, we twisted some rods (180 degrees) while the near maximum load was on them. No difference.

Over shorter lengths, however, we did manage to break rods from such twisting. You can't twist just the last couple feet 180 degrees and not do some damage. And, if you lock the tip down and start turning the butt, going a full 360 degrees, you'll certainly damage the rod and it will fail later under load. Surprisingly, to actually get the rod to break while twisting, we had to perform a minimum of 3 full revolutions to actually get the rods to split and fail.

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Thanks Tom. Pretty much confirms my thoughts and experiences. Were the breaks caused by twisting 3 revolutions quite different looking from other types of breaks?

Yes, and very easily to identify. In fact, even before they broke there were spiral lengthwise splits in the surface of the blanks.

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A half turn of twist may not damage a rod but I doubt it does it any good. I wonder if you performed that half twist a few hundred times and then loaded the rod to failure what the case would be. I have no way of knowing, but I tend to think that each time you give it a half twist it might do just a teeny tiny bit of damage and after a few seasons maybe all that twisting would add up enough to then reduce the power or strength of the rod to the point where it would fail at less than its design load.

I build all my baitcasting rods in spiral wrap fashion. I'm not taking the chance.

You may be correct, I don't have tests nor data to say otherwise. Obviously every time you stress a rod blank in any way, even just a simple straight bend, you weaken it even if by a miniscule amount. Repeated twisting over the course of many fishing hours would certainly cause additional fatigue. But I can't say by how much, how soon or if it makes any practical difference - we didn't perform any tests along those lines.


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Tom, I made a comment in the thread just above this one. I may be way out in left field. Seems to me every time we make a forceful cast with a conventional reel we are putting the tip top through several degrees of twist. The guys doing the big time pendlum casts have that tip all over the place. When the rod is straight back and fully loaded, and then fully forward right at the point of release of your thumb from the spool...I could see more than 90 degrees rotation happening.

Have I got it all wrong?

You're not wrong at all. The rod will always at least attempt to turn towards the direction the load is being applied from. Whether it becomes an issue that creates a problem over the long haul is another matter I think.

Most good graphite rods will take a lot of hard use before any fatigue becomes noticeable. So I'm just not sure this is an issue we need to worry about. I do know a lot of surf casters that honestly feel they can literally wear out a glass rod in a single season, but those glass rods fatigue much, much more quickly than a graphite rod does.

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