Rod Design
The buzzword for rod making today is "Modulus"
which is just a term for the shear strain testing of the
graphite fibers used. Most consumers believe that the higher
the modulus rating in a rod the higher the quality must
be. Yes the higher modulus fibers help to add certain positive
performance qualities to a blank. Qualities like quick recovery
time, crisp actions that cast well with more precision and
less effort. But, the higher modulus rating comes with a
price. The blank will be very brittle and prone to failure.
A more important factor, and ignored feature of modern graphite
fabric is the "Strain-Rate". This is just a term
that relates to the amount of stretch a fiber can take before
it breaks. High modulus graphite fibers have a low strain-rate
and are prone to failure where most Intermediate fibers
have a high-strain rating. This creates a problem for rod
makers. How to design a rod that has a light physical weight,
high modulus, and a high strain-rate. The answer is engineering
and design. We have engineered a rod design that uses a
mixture of graphite materials and resins, placed just right
in a pattern that enhances all the good qualities desired,
plus smooth taper transitions for the durability and performance
required by the pros and the weekend angler.
Effective
Spine
Every
fishing rod blank that is manufactured by rolling material
around a mandrel will have a hard side (or stiff side).
This hard side is call the spine (or spline). There are
forces generated during manufacturing that cause this hard
side to drift throughout the length of the blank such as
epoxy resin curing, material wraps in any given place, and
of course the consistency of the material being applied.
To
assemble a balanced rod one must find what is called the"Effective
Spine". This is the average of all those forces that
are creating the hardness on one side of the blank. In other
words there will be a line from butt to tip that will be
"stiffer" than the rest of the blank and this
area will resist bending more than the rest of the blank.
We identify the "spine" in our blanks by using
a Spine Finder, a piece of equipment that has raceway roller
bearings in a 10" tube that is set at a 45 degree angle.
The blank is place inside this tube and down pressure is
applied to the tip of the blank sufficient enough to mimic
the weight needed to load the blank as in a cast or fighting
a fish. The spine will roll to the top every time this is
done. We then mark the blank for assembly.
Placing
the spine in the top position when you assemble a rod is
very important to it's performance. For example: when building
a casting rod you want the guides to be place on the same
side as the spine. Why, because the blank (spine) will always
roll or torque away from the load. In fishing rods the load
is always "down", so if you put casting guides
opposite the spine, every time you cast, set the hook, or
fight a fish the rod will want to turn in your hand and
roll to the top. This makes for a very uncomfortable day.
Have you ever had a rod that would cast to one side or the
other no matter where you aimed? Well if the spine is off
when you load the rod to cast it will torque to one side
or the other every time you load the cast.
Now
on the other hand, a spinning rod's guides need to be placed
opposite the spine. Spinning guides are on the bottom of
the blank or towards the load. So if you put the guides
on the spine side, which would put the spine down, every
time you worked the rod the spine would torque away from
the load, or up.
To
summarize, the spine must always be place on top away from
the load. Unless of-course you cast backwards over your
head and fight the fish upside down????
Power
Rating
Furnace
Bay Bass and Inshore rods are given a power rating based
on an industry standard incorporated years ago. The standard
is basically the amount of force needed to bend a certain
rod to its’ full flex point held at a 45% angle. To
make it simple this is done by placing the blank locked
at a 45% angle and then certain amounts of weight are applied
to the tip until the blank flexes to the theoretical full
bend.
Once
this test is performed a rating is applied to the blank
that correlates to a line class. This means that a power
rated rod should flex under strain using the lowest line
weight in that class without breaking the line. The upper
end of the weight scale is an estimated line weight that
the rod can handle without the blank breaking.
The
rod can be used outside of the line class ratings but it
will not perform as well or load properly outside of those
parameters. This means, yes you can use 6lb test for a rod
rated for 8lb test, but you are now below the line class
rating and a hard hook set can break that line as well as
not flex easy enough to fight the fish properly and you
could break off. At the high end of the line class it is
possible to use heavier line but the warning should be that
you can overstress the breaking point and blank will break
before the line will under severe flex. Like anything else
these are guidelines to assist you in making the proper
decision when choosing a rod to the specific technique you
will be using. If a manufacturer finds out you are using
heavier line than recommended they will void your warranty.
But, most rod designers build in a little cushion for those
who like super lines. Just be careful and keep track of
the amount of strain you are putting on the blank.
Modulus
Terms
Modulus-
A measure of applied load (stress) that it takes to deform
a material in its finished process state.
Flexural
Modulus- measurement of elasticity, or flex under stress,
of a certain fiber used in the manufacture of a part. (i.e.,
Carbon, Graphite, Glass, Boron, Aramid, etc.)
Tensile
Modulus- measurement of shear strength or stiffness
of a part which is made from fiber, relates to stiffness
of a part made from that fiber. As modulus increases, stiffness
increases.
Modulus
is most commonly used in the terms to describe the performance
properties of prepreg tape made from fiber such as carbon,
or graphite, but does not relate to the actual performance
design of the blank pattern.
Prepreg
Tape- tape roll of fibers woven, weave, or layered.
Then impregnated and coated with resin. Rod Patterns are
cut from prepreg and rolled onto a mandrel to form the shape
and taper of the rod blank.
Furnace
Bay Rods Competition Rods
Using
upgrades in Graphite / Carbon composite and (new to the
fishing industry) epoxy resin lay-up we have improved strength
to weight ratios for greater performance and stability.
Our blanks have a Carbon scrim (sheet film) for control
of the main fiber orientation and will add additional stability
and "hoop strength".
Graphite
Strand Modulus - 58 MSI
Carbon Fiber Strain rate - 41 MSI (Toray)
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