A Look At Bamboo Rod Tapers

by

Tom Smithwick

( A Little Note On Tom Smithwick.  He is one of the nicest guys in fly fishing and he is also one of the best bamboo fly rod makers in the world.  A modest angler he does extensive work with the Wounded Warriors Project.  This is one of the best introductions on Bamboo Rod Tapers that you'll find anywhere.  Hope you enjoy it!)

The Basics

 
Lots of things can have an impact on the performance of a bamboo fly rod. The
quality of the cane, the type of glue used, flaming or heat treating, all make some
difference. But the overwhelming factor is the thickness of the material. The effect of
thickness variation is exponential, meaning small variations can quickly make a big
difference in the way the rod flexes. That is why fly rods tend to be described and
defined by their tapers.

So lets take a look at the major categories of bamboo fly rod tapers. First, imagine
that it is the mid 1800’s, and you are sitting down to design a fly rod with this new
method, split and glued up bamboo. Most likely, you start with nothing but the
intuitive knowledge that a fly rod is skinny at the tip, and fat at the butt, and you
would start by connecting those two points with a straight line. That’s not such a
bad idea, and you would soon find out that the slope of that line had a major impact
on the feel of the rod, and that the starting thickness at the tip determined the
weight of the line that could be cast with the rod.

Skipping forward some years, a man named E. C. Powell, codified such tapers, and
determined that a good basic slope for such a taper increased in thickness three
thousanths of an inch (.003) for each inch of rod length. Mr. Powell designed rod
tapers in 6” increments. For each increment the thickness of an individual cane strip
increased .009, but when the rod was glued up that thickness was doubled to .018,
which resulted in a .003/inch slope. He called that slope a B9 taper. The thickness
chart below describes such a taper for an 8 foot 6 weight rod. The taper starts at
.075 thickness at the tip, and ends at .363 at the butt at 96”. The ferrule dimension at
the 48” mark is .219, just about perfect for a 14/64th ferrule, exactly what you would
expect on an 8 foot 6 weight of moderate taper. If I wanted a 5 weight 7 ½ footer, I
would start the tip at .068, which would produce a tip that would respond nicely to
the 5 weight line, and the center dimension would be .203, exactly right for a #13
ferrule. Again, exactly what would be expected on a 5 weight rod of moderate action.
Mr. Powell himself described the B9 taper as an all purpose fly rod, easy for just
about anyone to cast, having both good accuracy and distance casting capabilities.
There are curved Powell tapers as well, a description of which is beyond the scope
of this essay.

 
 
I should point out that the program I used to generate these charts calculates only to
the front of the handgrasp on the rod, so the charts stop at 85”, even though all the
rods are 96” long. The program also generates an ”equivalent straight taper” line on
the chart, which gives you a good idea of the average overall slope of the taper, a
useful bit of information if looking at a taper where the actual measurements zig zag
around a bit. On the other charts, the green line is the actual taper. On the chart
above, the lines overlay each other.

So, to continue with the discussion of straight tapers, the Powell B9 formula
produces a medium fast action, and by varying the starting thickness of the tip and
the length of the rod, you can produce useful tapers in just about any line weight.
But suppose you want a slower, more relaxed action. What happens is you start
lowering the slope of the taper. That works for a little bit, but if you lower it too
much, the rods starts to develop a mushy feel, in which the butt of the rod no longer
has the strength to turn over the tip with any authority. Conversley, If you start
raising the slope, you will reach a point where the butt of the rod stops bending, and
other than a bit of leverage, contributes nothing to the cast. The overall weight of the
rod may start to feel opressive as well, depending on the caster’s level of arm
strength.

Lets look now at somewhat slower tapers, those than can be described as having a
progressive action. In order to make them work without feeling mushy, a drop in
taper is introduced in the tip area, which allows the tip to remain responsive, even
though the butt is a bit weaker. These tapers are quite popular, and in my own
opinion best showcase bamboo as a rodmaking material. They offer a good compromise between light weight and performance. They require a little slower,
more controlled casting stroke, but are not tricky to cast with a little experience. The
series of tapers by Everett Garrison are excellent examples of this kind of taper,
constructed around an average slope of about .0028/inch.

 
 
 
The taper depicted is the Garrison 212E, an 8 foot 6 weight, with a very smooth
action. Characteristically of such tapers, if you are casting it and start extending the
casting distance, the amount of increasing effort seems directly proportional to the
increasing length of line. That, and the reasonable weight of such a rod makes them
easy to fish with during a long day on stream. Such tapers have always been
popular on the West coast with those who fish for steelhead, which requires long
days on the stream, casting heavier lines, and keeping the fly in the water. The other
Garrison tapers are all very similar, varying by length and line weight, but following
the same design philosophy. Both the Garrison tapers and the Powell tapers are
mathematically derived, and their originators made the tapers and the mathematics
public, so they usually will be depicted as very smooth curves or straight lines.
The remaining examples will show irregular tapers, which might be a result of the
fact that they were not published, but rather taken off of existing rods, and show the
result of manufacturing tolerances as opposed to the planned design. Or they may
have been derived from experience by adding or subtracting material from an
existing rod, as opposed to a mathematical approach. There is nothing wrong with
that, it’s a time honored approach. Another approach to fly rod tapers with a lower than average slope is the much misunderstood parabolic taper. A wise friend once advised beginning rod makers  that the first tool they should purchase is a shovel for all the BS they were going to hear. The actual derivation of the term “parabolic” is again beyond the scope of this article.

But discussions by people writing catalogs to sell rods, and therefore people
influenced by them are virtually always nonsense. No rod bends like a parabola, and
no mathematical or engineering derivation of a taper looks like a parabola. Rod
makers all agree, however, that a parabolic taper is one with a reasonably strong tip,
a very strong middle, and a weaker, full flexing butt section. The principal designers
of such tapers were Charles Ritz, working with Pezon & Michel in France, and Paul
Young in the USA. Both designed large numbers of such tapers, and both apparently
did a lot of experimentation to get them exactly right. I consider them the most
difficult tapers to design correctly, particularly in longer lengths. The big trick is to
get the full flexing butt just right. If it flexes just a bit too much, you have a rod which
will not cast the line with any authority. If it does not flex enough, all you have is a
rod which casts like a progressive taper, but which weighs too much because of the
heavy middle. Even a correctly designed parabolic rod requires some skill on the
part of the caster, who will be required to make a full, but slowly accelerating stroke
with a controlled stop at the end. The longer the rod, the more skill is involved.
Many people can easily cast a shorter rod, such as a Young Driggs River, but a Para
17 or a Ritz Fario Club is a different experience. In any case, here is the taper chart
for one of many versions of the Young Para 15, one of the most popular parabolic
tapers ever designed.

 
The 15 in the name refers to the fact that it is fitted with a 15/64th ferrule, a full size
larger than what is found on a similar progressive taper. That is quite typical. The
result is that a parabolic rod weighs a bit more, and that the weight is felt more in
the middle of the rod. So there is a penalty in felt weight by the caster. The upside is
that a well designed parabolic rod will cast a very long line for its size and weight. I
mostly don’t feel the extra weight is worth carrying around, unless I’m going to be
making long casts all day long. To each his own.

There will always be people who prefer a fast rod, and there are a few different
approaches to that as well. If someone asks me about a fast rod, I always think of
Lisle Dickerson, although there certainly were many others. Here is a Dickerson
8014, one version of his classic 8 foot 6 weight.
 

 
 
 
Note the very fast average slope, of almost .0034/inch. In a way, this is kind of an
atypical taper from him, as I would normally expect to see a step down taper,
meaning that the tip would be about .015 lighter than the butt at the ferrule station,
which would require the use of a ferrule made to accommodate such a taper drop.
The result on the rod action is to force most of the bending into the tip section,
producing a much faster action that many prefer. You will also sometimes see a
difference in the slope of each section at the ferrule, with the tip having a slower
slope than the butt. Here is a look at another version of the 8014, that exhibits the
dual slope method. My guess is that the original had a step down taper that got
averaged out by the taper program, something you have to watch out for.

 
As the title indicates, this was a basic discussion. I have not touched on length vs.
weight, hollow building, weight of components, and the variety of other variables
that make rod design so interesting. Then there is the ultimate variable, the caster.
Another wise old friend once told me that it is impossible to design a rod that
everyone will like, no matter how good you think it is. It is equally impossible to
produce a rod that everyone will hate, no matter how bad you think it is. I hope that
this little exercise has given those just getting started with cane rods some basis to
start figuring out what they do or do not like.