Inherent in the construction of banjos are certain parts that help address the needs of banjo set up. Among these are what we will call your “hot rods” - the coordinator rods and the truss rods. But what does all this mean to you, the player, when it comes to banjo set up?
We get a lot of questions from our beginner banjo customers about making adjustments on their banjos and these two particular parts of the banjo are sometimes regarded with fear and apprehension. This “hot rod” topic is complicated by myth and misunderstanding commonly borrowed from the world of guitars by both players and technicians.
The first thing we want to know is what each of these rods do, the reason that they exist, and then how they work together so you can do a proper banjo set up.
The truss rod is usually some sort of steel threaded rod that is embedded in a fretted instrument neck beneath the fingerboard. There are adjustable truss rods that offer “adjustment” to the amount of curvature in the neck and there are truss rods that are a stiff, solid material that are not adjustable.
The first myth regards the use of the truss rod. Folks believe you use it to “prevent the neck from warping” because of the tension of the strings. Well… Yes, sort of, but not exactly.
The Effects of Mother Nature:
Traditionally, banjo and guitar necks have been made of woods like, maple, mahogany, walnut and other various hardwoods. Also traditionally, some have had fingerboards made of rosewood or ebony that is glued to the playing surface of the neck.
Woodworkers throughout history have learned that gluing two different species of wood together, depending on the shape, thickness, size etc., can be subject to issues of “natural movement of the woods.” In other words, when we glue an ebony fingerboard to a maple neck, the ebony will expand and contract completely differently than the maple. It is this combining of two completely different materials that both have their own expansion and contraction properties that causes “warping” or twisting in banjo and guitar necks.
The intensity of steel string tension can exacerbate and exaggerate the movement of these two woods but depending on how many strings there are and how thick or stiff they are, the string tension itself is not the whole story.
Truss Rod Effect:
Having said that, this is where a fixed rigid bar or a threaded steel rod can help equalize the pressure of the expansion and contraction of the combined pieces of two different species of wood… Particularly in something long and slender like a banjo neck or a steel string guitar neck.
Built In Compatibility:
Deering’s Goodtime banjos have necks made of hard rock maple and the frets are mounted directly into the rock maple neck without a separate fingerboard so there is no need for a truss rod. The proper curvature for the neck is built into the neck from the start. This is one reason we recommend the use of light gauge strings for the goodtime banjo because the proper curvature was achieved by the known tension of the light gauge strings that we use relative to the amount of curve needed to keep the banjo fretting as easy as possible.s
Deering’s new Artisan Goodtime banjos have a rock maple neck and a separate Midnight Maple™ Fingerboard. Because these necks have the same wood in them as the fingerboard, the expansion and contraction characteristics of the neck and the fingerboard are the same. So again, there is no need for a truss rod because there are no conflicting forces that arise from two different species of wood and the proper curvature can be built into the neck during construction.
These techniques are not unique to Deering as there have been guitar makers as long ago as the 1960s that made maple necks with maple fingerboards and maple necks with no separate fingerboard and many of these guitars have achieved world-wide collector status and are still played today.
The second myth of a banjo or guitar neck is “It should be flat”. This is completely false.
The properly installed truss rod that is “adjustable” does allow the player to “contour the curve of the neck” so the strings can be plucked and they will not touch frets on the fingerboard.
A third myth that comes from the world of guitars is that “the truss rod is how you adjust the action, or playability of your instrument.” This is not the whole story.
The truss rod does not change the neck angle that it is mounted to the body, just the neck curvature.
The rod or rods that run through the middle of the body of the banjo serve three functions: they hold the neck tightly to the banjo, they help “stabilize” the banjo’s rim and the rod that is closest to the player’s tummy can be used for very minor action adjustments. Some banjos have one rod (like Deering’s Goodtime banjos and several Vega models as well) and some have 2 rods like the Deering Sierra, Deluxe, etc.
In banjos that have two coordinator rods, the rod that runs in the middle of the body of the banjo (the one that is closest to the strings) is strictly a stabilizing device and also fastens the neck to the body of the banjo. It is not capable of any action adjustment whatsoever.
When a banjo neck has the proper curvature for the tension of the strings being used and the neck angle is properly cut, the banjo will play its very best.
As banjo players, we are all working toward a very clear tone. With the exception of course of some of the new, young players who are adapting their banjo playing to rock ‘n roll music and using electronic distortion with their banjos like they do with their guitars.
When searching for a repairman for your banjo, be certain that your repairman works on acoustic guitars and banjos so the understanding of the neck curvature is part of their everyday routine. Electric guitar techs may be extremely skilled but if someone recommends the fingerboard be completely flat, this will not work for your banjo adjustments.
So, the truss rod must have the correct amount of relief adjusted into the neck or, for banjos with no truss rod in the neck , the neck must be shaped or carved with the proper amount of curve built into the neck. This is where the action adjustment starts.
Next, a banjo should have the tension of the head adjusted to the tone that the player likes with the bridge height that is compatible with the neck angle.
And finally, the neck angle must be extremely precisely cut so that the angle is compatible with the height of the bridge in the curvature of the neck for the most comfortable playability and clearest tone.
Adjusting coordinator rods and truss rods in Deering banjos is simple. What can cause complications is expecting adjustments to have more effect than they are designed to have. Trying to correct a neck angle more than string movement of 1/32 of an inch at the 22nd fret is asking for tone trouble or even part breakage for both the truss rod and the coordinator rods. Fortunately, Deering banjos generally don’t need these kinds of massive adjustments.
… And that’s one major reason Deering banjos are fun to adjust in service.
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