I understand that the static test is part of the Rodbuilding dogma around here, and for whatever reason, it works. However, I'm building an 8wt Z-Axis, and had a day off from my real job and set up the rod 4 ways with some interesting results.

1-Sage factory spacing. While this works it produces the least desirable line path under load, particularly in the lower half of the rod. It also puts 5 guides on the tip section concentrating the weight of the guides and wraps there.

2-Static test #1. Followed the directions here, set it up, ended up with 4 guides on the tip section, not Sage's 5. Looked good but I had time and so...

3-Static test #2 Started over, winged it a bit, placed a guide at a ferrule and worked around that. Line path looked great under load, but the guides were in completely different locations than the first static test.

4-Guides placed with a computer program I got off the web. Honestly, this produced a perfect line path under load but didn't put any guides at a ferrule. This produced the best looking guide spacing by eye.

I ended up going with #4 since the line path was great and it looked good too.


So that begs several questions about static testing. It appears that static testing is HIGHLY subjective. Any 10 rod builders would get 10 different results depending on how they looked at the line path, how much load was applied, how many guides they had preselected and the like. Heck, even one rod builder with the same built in biases gets differing results on the same blank with the same guides. So what does static testing accomplish? Is it just to assure that any given guide spacing works OK? Anyway, it does not appear to be a repeatable test. I was thinking that with 10 guides on a 9 foot rod, almost any spacing would work and static testing does not accomplish much.

Quite honestly, I was surprised by how well the computer program predicted guide spacing. Since every blank should be different, the program should not be able to predict that, yet the rod set up perfectly. Maybe I just got lucky. I need to play with that some more.

The Sage factory spacing was way off in the lower half of the rod. Is that typical? You would think that with all the resources of a large company, they would get that right, or maybe it just doesn't matter that much. With that said, I have used St Croix spacing charts before with significant success. It would be interesting to apply St Croix spacing on Sage blanks but that might cause the world to spin backwards or something.

It's really too bad, there isn't a more rigorous way of setting up guide spacing on fly rods. Even something analogous to NGC for spinning rods would be a big improvement. Any thoughts on this? It has to be an area previously studied by fly fishing physicists or something.

Sorry about the long winded post, but I spent close to 10 hours on this project yesterday and I thought I'd see what the experts had to say, especially since my results were not what I expected.

Drew

Drew,

I totally agree. I use a spreadsheet prepared by another rod builder. I also do a static test and 9 times out of 10, I keep the spacing provided by the spreadsheet.

Thanks for sharing,
Andres Perez
Miami, Fl

The number of guides used has a great deal to do with your static testing will turn out. The more guides you use, the less important spacing is. The fewer you use, the more important the spacing is going to be.

Of course static testing is subjective - you have a human operator utilizing subjective opinion as to which particular spacing looks and works best.

I would recommend having a guide on or very near any ferrules. The greater stress concentration is going to be between any pair of guides, so having a guide on the ferrule lessens the stress on the ferrule itself.

................

Drew,

Factory spacing charts are just that charts. Some use old charts created many years ago. Some may use something tuned a little better to their blanks.

As you say, there is a good bit of subjectivity that goes into a static test. Every static test begins with some assumptions, either related to the size/number of guides, location of the butt guide or first guide from the tip, ferrule locations, etc. In it's purist form, the static test is an application the trapezoidal method for approximating the area under the curve from calculus. The static test in rod building is a way of choosing the line segments used in the approximation. Just as with the problem in calculus, there are a large number of solutions that depend on the distance between each point in the approximation. They can be chosen to be equidistant, variable distance spacing, progressive spacing, depending on the orientation of the line with respect to the blank, etc. Each approximation solution will give you something that is close to the area of the curve, just as a static test will give you something that is close to the natural curve of the blank. There is NO SINGLE solution that is perfect, in fact there are an infinite number of suitable solutions, unless you get to use an infinite number of massless guides ( or actually perform the integration in calculus).

The goal of the static test is to make sure that you have enough guides on the rod to distribute the load, and to try to keep the blank flexing in something close to it's natural curve, as well as increase line control, and aid with spacing the guides for actual fishing situations. If you place the guides horribly, you notice that you get a bow string effect and start pinching the rod together between guides increasing the stress on the rod that can lead to a blank failure if the guides are placed too far apart. As you may know, there are people who have fished surf rods with very few guides over the years successfully, and I've fished 6'6" bass rods with only 5 guides and a tip top, fewer than I would ever use on such a build.

Guide trains then become an exercise in compromise. One needs to have a sufficient number of guides and spaced so the rod blank does not fail. The guides should be selected to have a minimal impact on the efficiency of the rod, yet numerous enough for adequate line control. The greater the number of guides, the more line you move on the hook set, but you are also decreasing the efficiency of the rod. The fewer guides used, the lower the impact on blank efficiency, but there is a trade off in line control and fish fighting power due to the blank flexing further away from its natural curve.

In order to optimize the guide train, you then take your rod out and test cast it. Once you find the optimal location of the guides near the butt for line control during casting, you recheck your static test to make sure that the guides still distribute the load well. Once the line is under control during the cast, the remaining guides only server to keep it under control.

Joe

I agree with Mr. Kirkman on the use of a guide on the rod joint for the same reason.

I put the appropriate guide on the joint - typically the 2nd guide and then work from there.

For the typical 8-9 foot rod, there will be one guide on the butt section, one guide on the joint, and the rest from there as needed.

Roger

How a set of guides "looks" on any day is more attitude than fact. We can talk ourselves into believing almost anything.
How many times you repainted a room because it looked terrible the next week.
I use a spreadsheet and look at the flex after wrapping. If I've selected a profile close to the blank taper it will be fine.

Gene