I understand Graphite Modulus and all of that. Are we getting to the point int he rod building world where this is not even a factor due to resins and scrim along with the graphite? There has been some rumor that even some of the higher end blanks are lower modulus then some in the middle or lower end blanks? Can someone clarify this with accurate information?

Thanks


David Banaka

Modulus will always be important. Always has been, always will be. The point, however, is that it is not the only important facet of blank construction.

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Would someone summarize modulus and the trade offs. Higher is better? Always? Im sure there are a great many details with many variables. Just the nut shell version.

The higher the modulus the more efficient the blank can be. The same stiffness but at less weight. However, there are trade offs. A less substantial structure (you don't need to use as much material) and thus less durability (unless you reduce diameter and thicken the walls, at which point you lose the very reason you went to the higher modulus material to begin with).

Overall, modulus is certainly important but it does not dictate the entire story of what a rod blank is going to offer. The diameter, wall thickness, taper, etc., play equally major roles in how the blank is going to perform.

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David,
Higher modulus is not the only characteristic of a blank that is important. We use carbon fiber for blanks because it has a combination of characteristics that make it better suited to fishing rod blanks than any other material. It has high modulus of elasticity but also because it has low weight reasonably high toughness and reasonably high tensile strength. For example, some alloys of steel actually are better than carbon fiber in all respects except weight. You are right that the resins and the scrim have improved and the ratios of scrim and resin to carbon fibers is very important but the carbon fibers are still the most important material in the blank.
Higher modulus will result in a rod that is lighter and more sensitive which is important in many applications but in some applications the higher toughness of a lower modulus blank is preferable, a heavy boat rod for example. The higher the modulus the lower the strain energy or toughness.

You mentioned the modulus of a blank and we all do that and generally understand what we mean but actually the modulus of elasticity is a property of the material that the blank is made of which translates into the blanks stiffness and weight. A blank does not really have a modulus of elasticity.

To answer the other half of your question, generally the higher modulus blanks will be more expensive because the material costs to the manufacturer are higher but manufacturing cost and price are not always directly related, particularly with some of the high profile, big name, blanks.




Edited 1 time(s). Last edit at 03/01/2006 09:56PM by Emory Harry.

Tom,
You and I must have been typing at the same time.

Thank you folks.

David Banaka

David,
Do you have a library of the past issues of RodMaker? This subject, like most of the subjects that come up, has been covered in a lot more detail in past issues of RodMaker. I think that custom rod builders would all do themselves a favor by having a library of the past issues of RodMaker to use as reference.