There have been numerous posts on this Board, both pro and con, concerning the use of a spiral wrap configuration on fishing rods. During the manufacturer's panel in Charlotte technical representatives of Lamiglas, American Tackle, Batson, St Croix and Pac Bay described the present state of the art concerning blank design. The St Croix blank design engineer described the use of a high speed computer simulation program used for blank design that had the capability of predicting the results for a chosen set of variables

I am a small builder of salt water popping and bass rods. Most of the failures on the popping rods have been due to owner misuse. The bass rods, guides on top, have a failure rate that is troublesome. Nearly all of the failures have occurred in the heavy end of the blank just above the first guide. Nearly all of these failed blanks the "fisherman" told me the thing snapped while setting a hook. I have not had a spiral wrapped bass rod fail in this manner.

Do you have or can easily obtain information that deals with the following.

1. Can the computer simulate bending until failure with the spine on top with 0 degree tip rotation. Where is this failure most likely to occur?

2. Can the computer simulate bending until failure with tip rotation at 90 degrees and 180 Degrees. Does the direction of rotation when condidering the direction of the cloth fibers have any effect? Where are these failures most likely to occur?

I have not seen a position statement by any of the blank designers concerning the use of the spiral wrap system. If you have or know of some printed information, with real hard data, that could be used when talking with a potential custom rod customer could you please share it.

If you have any non- proprietary information or other comments on the reduction of blank failure rate by the spiral wrap methods employed by custom rod builders they will be greatly appreciated. Yep, I would even like to see the information if you truly feel there is no advantage to the methodology pertaining to blank failure rate.

Thanks Gon Fishn



Edited 2 time(s). Last edit at 05/08/2005 02:31PM by Bill Stevens.

Bill,
I do not know what simulation software that St Croix is using but there is software called Finite Element Analysis that virtually every mechanical engineer is going to be familiar with that can do just what you are asking. If you know or can get in touch with a good mechanical engineer that is a fisherman and interested he will more than likely be able to give you what you want. However, he will need to know quite a bit more about the material in the blank and the blanks dimentions than is normally available from the blank manufacturers. If you can get from the manufacturer the particular prepreg that the the blank is made of I think that the characteristics of that prepreg is available on the web. Plus you may have to destroy at least one blank by sectioning it to get all of the sectional dimentions that will be needed.
I doubt that there is simulation software that is designed specifically for blanks or rods but Finite Element Analysis has been available for a lot of years and there are probably versions of it now that will run on a good PC.
Maybe there is an ME that will see this and respond.

Rod blanks are made to withstand some amount of torsional stress. There is at least one manufacturer that employs a rotating load device to test blanks throughout a 360 degree rotation to ensure that the blank is equally strong on all axis'.

If you take a rod and clamp the butt so that it cannot turn. Then install a top or something on the tip so that you can gain a good hold and then twist the tip around a full 180 degrees, you'll be surprised to find that most blanks can withstand this without breaking (some cannot, and will fail on you the first time you try this). Length and power also play a role here, insofar as which can take this kind of abuse and which can't. You are not going to twist a rod beyond 180 degrees in an actual fishing situation.

Is such twist good for a rod? Not hardly, but I don't have any data to provide you with that would show how much, if any, a rod is weakened each time you twist it to such a position. I suspect it could break a rod down over several seasons if this happened routinely while fishing, but I cannot state for sure that it would. Minor twisting here and there isn't likely to damage it, however.

If you're asking if a spiral wrap somehow weakens a rod - it does not. A rod that does not twist is never going to break from being twisted. Another advantage of spiral wrapping.


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I am seeking test or computer modeling information confirming or denying that torsion of standard guides on top will add additional forces to a deflected blank that will contribute to failure. I did not intend to imply that spiral wrapping contributed to failure. Just looking for hard data in case someone has it.

Gon Fishn



Edited 1 time(s). Last edit at 05/08/2005 08:54PM by Bill Stevens.

A rod with the guides on top will not fail prematurely due to torque under normal circumstances or normal fishing conditions. The torsional strength of a blank is not as high as the strength under tension or compression but the torsional stress and strain are also not as high as the stress and strain under tension and compression. There is normally not nearly as high a torsional stress or strain on a rod.
I will sure admit that normally there is likely to be higher torsional stresses with the guides on top than with them on the bottom but there can also be significant torque on the rod when using a spiral wrap. Think about the situation when the load (fish) is off to the side at a high angle. In this case the torque can actually be higher with a spiral wrap then with a conventionally wrapped rod because the line will be riding in the guides at a point that is farther from the center or neutral axis of the rod and torque is this distance (moment arm) times the applied force.

Bill,
If you are, as you say, only seeking information that will support a belief that you already hold then no computer modeling or simulation software will do that for you.

No, with both rods in the same position and the fish at the same angle, any torque on a spiral wrapped rod must be less than it would be on a conventionally wrapped rod. Unless of course, it's a flying fish and has left the water and is somehow managing to stay high in the air during the fight.

A high angle? The fish will always be below the rod. It would not even be possible for the load to be at 90 degrees unless you pushed the rod down to the water's surface and the fish was at the surface itself.

On a conventionally wrapped rod, the load will always be coming onto the guides from a very substantial angle. Not so with a spiral wrapped rod. In fact, on a conventionally wrapped rod, the angle of the load to the guides will always be greater than 90 degrees, on a spiral wrapped rod, it will always be less than 90 degrees. Unless that flying fish is back on the hook again.

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Edited 2 time(s). Last edit at 05/08/2005 10:15PM by Tom Kirkman.

Tom,
Lets say that the load (fish) is off at a 45 degree angle. With a conventionally wrapped rod, the guides pointing up, the line will tend to ride at about a 45 degree angle to vertical, relatively low in the guide or toward the bottom of the guide. Now lets rotate the rod 180 degrees or spiral wrap the guides so that the guides are now on the bottom of the rod, pointing down. The line will again tend to ride at about the same 45 degree angle, but now toward the top of the guide or in the guide at a point farther from the rod because the guide ring opening has some diameter. How much farther will depend on the size of the guide. Because the line is riding at a point on the guide farther from the center of the rod there is a larger moment arm. If the force is the same in both cases the torque will be higher with the guides on the bottom. In this case the torque will be higher for a spiral wrapped rod then for a conventionally wrapped rod.

"You are not going to twist a rod beyond 180 degrees in an actual fishing situation. "

Tom - that might not neccesarily be true. Hypothetical situation - Guides on top rod, which hooks into a large fish. Fish makes a run straight down under the boat - assume the rod tip twists and the first 2 or 3 guides are now towards the bottom - basically the tip has been twisted 180 degrees, assume clockwise. The fisherperson lifts the rod to try and stop teh fish, but he doesn't lift straight up, he turns teh rod slightly counterclockwise for whatever reason. TEH tip of the rod will still be pointed straight down, but now the but of the rod has been twisted teh opposite direction, making the entire rod twist more than 180 degrees.

Emory,

I knew you would return with that argument (And I'm sure you're also aware that as the rod twists, the length of the moment arm changes as the line changes position within the guide ring). But even in that situation, the rod is only going to twist or turn until the guides are nearest the direction of load. So even in your scenario, it is the conventional rod that will attempt turn or twist the most. At a 45 degree load, which would be fairly extreme, the spiral wrapped rod will attempt to move or turn just 45 degrees. But the conventionally wrapped rod will attempt to turn or twist by 135 degrees. I know which rod I'd rather have in my hands.

We did this same test on the device I had in Charlotte. In any practical application of load, the spiral wrapped rod never had to move much to stay in line with the direction of load. The conventional rod, on the other hand, would not stay upright. It required effort on the part of the fisherman to remain upright. There is simply no valid argument that somehow a conventional rod will ever be anywhere near as stable as a spiral wrapped rod (or a fly rod or a spinning rod). Unless and again, that pesky flying fishing is back on our line. Nor is a spiral wrapped rod ever going to be subject to the the kind of torsional stress on a blank that a conventionally wrapped rod wil bel. Whether or not that stress is harmful, we don't have any data on.


Billy,

You're correct. I suppose you can do all sorts of things that might take a rod through more than a 180 degree twist. And as I'm sure you also suspect, when that happens you often have a rod failure. Most rods can withstand some torsional stress but when you start to make a full circle, it's going to bust.

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Edited 1 time(s). Last edit at 05/09/2005 08:59AM by Tom Kirkman.

I'm not a blank designer but if I was a fishing judge I would sentence Emory to a full day's bottom fishing for either Halibut or Grouper. Big ones. Then I'd stipulate that he'd bring up the first few fish on a conventionally wrapped rod and after that, just one with a spiral wrapped rod. I feel pretty sure he'd have a quick change of mind on which rod works better no matter what the numbers and figures say.

I also offer the contention that a rod that has had the guides wrapped along the top is a very poor engineering design to begin with. It's like trying to cross a cable by tightrope walking rather than suspending yourself underneath. Every other similar contraption that operates on the same principles puts the load supported underneath, not on top. Someone once said that "guides belong on the bottom of all rods" and those of us that have fished both types under a pretty wide variety of conditions would agree. From an engineering standpoing it's the better design.

Tom,
You knew I would come back with that agrument?? I agree with your point when the rod twists and I would also agree that the spiral wrapped rod can not twist as far. But the question was the amount of torque on a spiral wrap versis a conventional wrapped rod. I think that you will have to agree that under some circumstances the torque can actually be higher on a spiral wrap.

Denny,
You do not have to sentence me to the terrible fate of a days Halibut or Grouper fishing. In that type of fishing I think that the spiral wrap would be a definite advantage. And I completely agree with your point that the spiral wrapped rod will tend to be more stable. That was not the issue. The issue was torque. It has been said here a number of times that there is no torque with a spiral wrapped rod and I was just attempting to point out that this is not really true. That in some cases the torque can actually be higher with a spiral wrapped rod.

Now the question becomes how much torque is there really. I think that in the example that you have picked the torque could be significant but I think that in many types of fishing situations the amount of torque is insignificant.

Bill, I am just a rod builder so I am just going to stick with the basics, In the vast majarity of the cases where the rod broke where yours are being broken the fisherman has gotten hung up and grabed the rod at the broken area[ he thinks he is supporting it] creating a shear point and then yanks on it breaking the rod. Fishermen being the "Machoman" is never going to own up to doing something stupid so they make up a story about how the rod just "broke". Jesse

Torque won't hurt a rod unless it causes the rod to twist. And I think that's what we were discussing here (at least I was). If the amount of torque on a spiral wrapped rod was greater (and yes I agree the force could be greater in some scenarios), and that on the conventionally wrapped rod was less, the one that suffered the most damage would still be the one that twisted or turned the farthest, not the one that simply had the most torque on it.

If you twist a blank around far enough, it will break (you can try this at home). So at some point rod twist is a bad thing. I think what Bill wants to know is at what point does such twist become detrimental to a rod's health.

I think it would more than safe to say that any torque applied from a normal fishing situation will never hurt a spiral wrapped rod but could possibly harm a conventionally wrapped one. You will never see a spiral wrapped rod damaged due to twist under actual fishing situations. You may see conventionally wrapped rods damaged from twist, however (I have seen some break although these were extreme conditions). And conventional rods certainly require more effort on the part of the angler. The amount is certainly linked to the size of the quarry, but just as we try to minimize weight near the tip of our rods to maintain as much performance as possible, the ability to reduce angler effort by any amount should at least be considered. Most bass fishermen I know claim that they can tell a difference in effort required to fish the two rod types and bass really don't get that big.



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I don't think I buy this. If you could put a measurement device at the very butt end of both type rods and then mimic an approximate fish pulling load on a line through the guides and out the end of the rod, I don't think that a spiral wrapped rod could ever be under the type of torque that a conventional rod would be. The line moves in the guides so it can't 'grab' them and hold onto a certain point. By the nature of the guides on a conventional rod ALWAYS trying to get to the bottom, that rod is going to be under more stress and torque no matter what. I hate to argue with so called facts and figures, but somebody isn't applying them correctly. You don't have to do very much to try both rod types and see which one puts less torque on the fisherman. The difference is huge and even quite noticable on even the lighter freshwater rods.

Denny,
Exaggerate the size of the guides and then think about where the line would be if the guides were very large say a foot in diameter. Now you can see that the line will be much farther from the center of the rod when the guides are spiral wrapped. How far the line is from the center plane times the force is the torque so any force that is off axis, like a fish pulling to one side, will result in higher torque with a spiral wrap.

I can't imagine I would ever build a fishing rod with exagerated guide sizes. Are we talking about real life fishing rods, or screwball scenarios to prove a point??? Even if the torque would be more you would still have less rod twist. What fishermen don't want is to have to fight rod twist. It takes more effort to fish a conventional rod than one with the guides on the bottom. That's a fact. Maybe in most light freshwater cases it's just a little more effort while in heavy saltwater it's a lot more effort. But either way, it's more effort.

Rods with guides on the top are based on a very bad design. You've spent the past year trying to come up with supposed disadvantages of a spiral wrap but there really are none that any of us users can see. They cast just as far, they don't twist, they are easier to hold and fight a fish with and they don't break any more often than any other kind of rod. They're just better all the way around.

For the record, I really don't mean any offense but it's starting to get silly. Anyone who has fished the two types of rods knows the difference and to try and sway anyone with outlandish scenarios or figures that don't matter to actual fishing use just use up board bandwidth. IMHO anyway.

Denny,
I do no have to prove anything to you. I only used the exaggerated guide size in an tempt to make the point clearer to you so that you would understand. I will not make that mistake again.

I have built a few spiral wrapped rods to complement the 100 spinning/casting rods I already have. The first two that I wrapped I must have screwed up on. Everything seemed fine, but when I fished them, I was dissapointed. I ended up with more friction (by the sound of the line on the guides and how loose my drag had to be to lighten the load on the rod/line when fighting a big black drum. The last one turned out much better.

The one thing that I have noticed more than anything, is that on my rods I wrapped with lightweight rollers (which I love), any slight turning of the wrist/reel when fighting the fish ends up with a major twist in the tip of the rod. It gets so bad that sometimes I have to physically turn the rod to keep the line perfect on top of the rollers. It looks fine at the butt but twist towards the top.

Sounds like a good point for the @#$%& rollers for me.

Phil