Adjustments at both ends for a more refined fretboard profile
announcement by Emmett Chapman, March 2010
The Stick's new "Divided Truss System"™ consists of a single truss
rod firmly pinned down at the midpoint in its rear channel of the
neck, thus creating two independently adjustable truss sections.
This allows individual truss settings for the lower and higher
During my final setup phase in recent Stick production runs, I've
enjoyed having this refined control over the entire fretboard
profile, individually "tweaking" each nut at opposite ends of the
If your Stick has this new feature, I hope you'll enjoy a greater
precision in maintaining an optimum setup for very low tapping
"action" and light touch. Your music and technique should benefit
from the fluent dynamics, expression, comfort and speed that such a
Typically, the newly added adjustment nut nearest the headstock
should be set looser to create some small "relief" at frets 2 to 8,
forming a slightly concave ("bowed") profile at this lower pitched
region. At the other end, the original adjustment nut under the
belt-hook is typically set tighter to form as straight a profile as
possible from the middle to highest pitched frets.
This new truss rod invention actually adjusts four ways. An
adjustable nut assembly sits in its own T-shaped "thrust cavity" at
each end of the rod, and can "pull" against the inner T-cavity wall,
acting in tension (like a cable) from the rear to correct any bowing
of its fretboard region. If need be, it can also "push" against the
outer T-cavity wall, acting in compression (like a jack) to expand
the rear neck surface and thus straighten any arching (back-bending)
of its corresponding fretboard region.
As with my earlier patented truss rod, this "Divided Rod"™ sits
flush with the rear neck surface, at its maximum point of force, and
thus acts in an unusually straightforward and predictable manner to
immediately straighten the neck.
Tension is usually all that is needed at both sections of the rod, by
way of tightening each nut just enough to counteract the pull of the
strings, thus straightening any bow wherever it might be located
along the fretboard. In some cases, however, an opposite truss force
is needed to conquer a convex neck profile at some particular fretted
region, and then the compressive force is available for convenient
use, by way of turning one or even both nuts in the opposite
Of course, both halves of the Divided Truss Rod, though fastened
stationary at the rod's midpoint, are still slightly interactive as
seen from the string action. If you tighten the original nut under
the belt-hook to straighten the higher pitched region, the strings
will drop a bit lower to the fret tips all along the board, and
inevitably, the string heights at the other end will drop by a small
fraction of that amount, necessitating a small counter-adjustment at
the "Flaps" dual nut unit to regain the ideal minimum string
clearance over the first fret.
Three flat-head Phillips machine screws are used to secure this
"4-Way"™ trussing system inside its channel and flush with the rear
neck surface at its midpoint under the eighth fret. These screws
should be kept tight so that the rod's midpoint never moves.
Both adjustment nuts have regular right handed threads, but because
they are at opposite ends of the same rod, they turn in opposite
directions to tighten their respective sections of the rod.
On December 8th, 2009, I received US patent #7 629 521
this new truss rod invention in the field of stringed instruments.
It makes my life easier as manufacturer and musician, and hopefully
will also make maintenance easier for you in the field and on the
road. Licensing inquiries by other stringed instrument makers are
welcome, of course.
All the Best, Emmett.
Divided Truss System, Divided Rod, and 4-Way Truss Rod are trademarks of Stick Enterprises, Inc.