Anybody know the modulus/strain rates for different blanks. I know this answer could fill a book but just looking for a few of the popular blanks around the 45 million range, 50+ million, and 60+ million.

Also whats the highest strain rate blank available for rod making? I know Bass Pro Shops makes an 85 million modulus rod but as far as I know the blank is not available to rod builders. Shikari had a 65 million modulus blank but they arent manufacturing it anymore. Also G.Loomis has the GLX around 65 million but the best Ive seen G.Loomis selling in blanks is the IMX at 55.

I know strain rates arent everything, but they are something. Unfortunately many people think the Modulus rating is all that matters.

Higher modulus fibers give you the ability to make a rod that is lighter for the same stiffness, in most cases, but there are so many other variables that you just can't go by modulus alone. And, as has been pointed out here many times, the modulus for the prepeg as it winds up being used in the rod isn't going to be anything like that advertised for the fiber itself. For the most part, modulus ratings were used by companies for marketing purposes. Most companies have backed off that sort of thing to a great degree these days and few even list the particular fiber or modulus ratings for the fiber used in their rods anymore.

Generally they will speak of the "generation" of graphite fiber used. First generation is usually in the 30 to 33 million range and was the standard for many years. The advent of IM6 brought about what most refer to as second generation fibers and falls in the range from anything above 33 million to maybe 45 million. Anything above that is usually referred to as third generation fiber. (Different companies may give you slightly different values for each generation than I have, but I think these are pretty close off the top of my head.)


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Thanks Tom, I know the general strain rates for the IM8, IM7, IM6, standard, and a few of the other lesser known like RX8, RX7, and the lower end G.Loomis and Shikari blanks, I'll post what I know below. But do you know the strain rates for the higher end G. Loomis, St. Croix, or other better blanks?


Standard- Typically 33 million.
IM6 - around 38 million, but some manufactures Ive seen as high as 43 million.
IM7- originally around 42 million.
IM8- Usually about 45 million

G. Loomis IMX - 55 million
G. Loomis GLX - 65 million
Shikari SHXi - 65 million (discontinued?)
Shikari SHX - 57 million
Batson RX8 - 51 million
Batson RX7 - 43 million
Batson RX6 - 34-35 million

First of all, you're not listing strain rates here - you're listing modulus. I had a sheet at one time that listed the strain rates for most of the popular fibers but I can't put my hands on it right now.

At one time, as the modulus went up, the strain rate generally came down, but that's not always true with the more modern fibers. It's not neccesarily a linear relationship across the board. I think IM6 was the first graphite fiber used in fishing rods that sort of "broke the mold" in this regard.


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Edited 1 time(s). Last edit at 03/31/2005 02:20PM by Tom Kirkman.

Ok, its modulus rating. Does anybody know the blanks with the highest modulus rating that are available to rod builders for spinning or casting?

Jay,
The modulus of elasticity number is for the graphite fibers alone not for the rod. Modulus of elasticity is stress over strain. This stress over strain relationship is linear up to the tensile strength ( the modulus number is actually for tensile modulus). To increase strain either the tensile strength must be increased or the modulus lowered. The term strain rate is a bit different but generally it is refering to the speed at which the blank can be flexed. Tensile strength drops as the speed the blank is deflected increases.
I think that someone has given you some bum dope about the modulus numbers you have. I was told by Loomis that IMX is actually made from standard graphite, modulus about 33 million, but it is light because it has graphite scrim while almost all other blanks have glass scrim. Every other layer in the material is scrim.
Also I do not believe that the 85 million modulus is a real number unless the percent of graphite is lower and the percent of glass scrim is increased. The reason I believe this is that the strain energy or toughness drops as the modulus increases. A blank built with graphite that had that high a modulus, unless the glass content is increased is going to be very, very easy to break.
To answer your last question directly, it is virtually impossible to know what blank has the highest modulus because the manufacturers do not tell you what the percentage is of glass and resin in the material (prepreg) that is used.
There is one additional issue that further complicates things and that is that some of the highest performance blanks being made today are actually being built from several different materials with different modulus of elasticities. The result is that the modulus varies in the blank as you go from the butt to the tip.

I certainly don't but I would be cautious of any claims for blanks that claim to have something like 85 million modulus fiber. They may well have some fibers in there that have such a rating, but I doubt the fiber content in those rods with that rating would be 100% of the make up.


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The Johnny Morris rods you mentioned have some 85 mil graphite "core" in them than a 1k low modulus overwrap. If you look at the Bionic Blade rods they have a lower modulus core, but the overwrap is of 3k higher modulus. Doing this dramatically drops the modulus of the blanks, anyone's blanks, there is a chance that the end modulus of both blanks may be very close. That's one reason why the St Croix, G Loomis, and Shikari blanks cost more, they use quality stuff throughout in the right proportions that ultimately makes a better rod. They try to maximize the blank using materials in the best known ways, and leave the hype and chasing the numbers game to others.

To totally make a rod out of a fiber that has an 85 million modulus rating, at least with today's technology and prepeg state of the art, would require a very small diameter and very, very thick walls. At which point you've pretty much negated why you moved to a higher modulus fiber or prepeg to begin with.

After a decade of "modulus wars" most of the better manufacturers have settled on fibers and prepegs which offer great performance with reasonable toughness. There is still a range with some rods being more efficient and a little less tough, and others tougher and a little less efficient, but overall most makers have settled on materials and designs that provide good performance with some manner of reasonable durability. When I see ads touting rods from fibers in the 70 million and up area, I tend to believe that most of what the maker is after is a little extra marketing gimmick. Not that such rods can't be any good, but I doubt they'll perform any better or even as good as many rods made from lower modulus materials with a little better design or production timeline behind them.

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There is one more point that should probably be added. We use the term modulus of elasticity as if it were a property of a blank but it was pointed out to me a year or so ago by a knowledgeable materials person that modulus of elasticity is a property of the material not of the blank. A blank has stiffness, power or spring constant, weight, resonant frequency, damping factor etc. all of which are effected by the modulus of elasticity of the material but a blank does not really have a modulus of elasticity.
At one time I thought that the blank manufacturers were being a bit deceptive in not providing the overall modulus for their blanks rather than just for the graphite fibers being used. But I now think that they are just being a bit more rigorous than we rod builders in their use of the term.

I've never used the term modulus as if it were a blank property. I never thought that it translated well to the final structure because the blank is not a material but rather the result of a combination of material and how it is used to create the structure. But I have seen at least a few builders argue that a rod or blank has its own modulus.

I would agree with your materials person that modulus is a property of a material, but not of a structure.

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