Fly Rod Tapers — Graphite, Fiberglass, and Bamboo

[ska1911]

Yes, the more i think about the idea of quantifying the contributions of these variables on rod actions the more i realise how difficult this is. Not just from the point that it's hard to find a valid measure for rod action but i suspect interactions between all of the mentioned variables, so this would most probably not give the clear results i was thinking about. another thing that came to my mind is taper in the context of different weight classes of the same rod model. Do the mandrels for a class 3 and class 5 of the same rod have identical slopes and just a different diameters? Or what are the variables that are kept constant to get a similar action for the different weights (assuming that the rods are really designed to have the same action) ?
Cheers
Stefan

[John Waters]

Material, taper, diameter and wall thickness are my variables in rod design.

John

[Merlin]

Hi Stefan

Do the mandrels for a class 3 and class 5 of the same rod have identical slopes and just a different diameters?

You may use the same mandrels for a class 3 and a class 4, but preferably not for a class 5 as well.

Or what are the variables that are kept constant to get a similar action for the different weights (assuming that the rods are really designed to have the same action) ?

Good question indeed, but the answer is proprietary.

Merlin

[DryFly]

Hi Stefan

Do the mandrels for a class 3 and class 5 of the same rod have identical slopes and just a different diameters?

You may use the same mandrels for a class 3 and a class 4, but preferably not for a class 5 as well.

Or what are the variables that are kept constant to get a similar action for the different weights (assuming that the rods are really designed to have the same action) ?

Good question indeed, but the answer is proprietary.

Merlin

To get the same rod but just a bit stronger/ higher line class one can just move down on the same mandrels for perhaps 1/2 inch.
With the same amount of material on a larger diameter, the blank will become a little stiffer but the risk of a break will rise a bit due to thinner wall strength.
If we want to have the same wall strengh, we cut the carbon flagg a fraction larger. This increase also the bending strength.
So there are the 2 variables - diameter and amount of material - but mounted on the same mandrel just a little bit further down, that will make the same rod just one class up.

[Merlin]

And what if a 4 piece rod is built on 4 mandrels of different slope?

Merlin

[Paul Arden]

In my experience and from what I’ve seen, every rod is built from scratch. We had a HT4 and a HT6 and it took something like 5 years and 9 attempts to make the HT5. Ok the 5 years is partly my fault (actually it was a lot longer than 5 years but don’t tell anyone!).

Making a rod to fit a gap I thought would be easier. If anything it’s harder.

Cheers, Paul

[RSalar]

Paul — what was your testing method to determine if the design “fit the gap”? Did you use any type of measuring devices or equipment? Or was it just you judging how the rod acted and felt while you were casting it?

—Ron

[Paul Arden]

From my side it’s casting (and fishing). I have a space in my head where I want to get to. Actually doing that takes some trial and error. It would be nice to be involved in the cloth shaping and cutting side of things and I know I would find that fascinating. But also quite impractical for me and I don’t think the process would be any different.

The very interesting thing in this process is we make rods that Alejandro doesn’t personally like. He likes softer rods. So we have ended up making rods that are not only different to what is coming out of other factories, but also what’s coming out traditionally of the Spanish factory! I like that

Cheers, Paul

[RSalar]

Do you make rods that serve a very specific purpose — not just to cast a certain line weight — but say for ultimate distance or for pin point accuracy, or for say delicacy of presentation, or for roll casting? Or are your rods designed to be all purpose rods?

Cheers,

Ron

[DryFly]

And what if a 4 piece rod is built on 4 mandrels of different slope?

Merlin

Why should it not fit?
When the slope of the 4 mandrels was different before, the male end had to be grinded to fit.
If we move downwards with the flagg on each mandrel, we still have the same slope/ slope difference.
Only, if the slope of 1 mandrel would change, then we might get a problem.
But as far as I know, a mandrel has the same slope/taper all over its length.

I do a lot of blank tuning in the + - middle of the blank.
So I´m used to grinding male ends to fit again.
Sometimes, when I have to grind a lot and lose too much of wall strength, I reinforce the male with an inner piece of blank.
Then I either elongate on the lower end to get the original length again or I leave it with the shorter length.

I just tuned an old Fenwick HMG 9´ "#10" blank ( about # 8 in reality) by cutting off about 10 inch of the upper end of the handle ( 2 piece blank).
Now it is 8 ft. 3inch, with a more progressive action and a higher recovery speed.
As I own also an original built HMG 9´"#10", it will be nice to compare the 2.

There are many ways to join 2 blank pieces.
On some modern low/mid priced blanks there is even some extra material on the male end to fit the female.

And I have made 2 piece, 5 - 6 ft. glass fly rods out of the 2 upper parts of old teleskopic coarse fishing rods by connecting them with spigot ferrules. As the inner diameters of the 2 pieces were quite different, I had to play around a bit, to get them fit.


Reinhard