Truss Rods & Side Adjust

Truss rods help wooden guitar necks withstand the constant tension of steel guitar strings. They are also adjustable, allowing players to change the curvature of their neck for the best playing action. Truss rods generally fall into two categories: the Vintage Single style and the Modern Double style. Both are available from Warmoth.

Vintage Single Truss Rods

The vintage style truss rod consists of a single steel rod that is held in a bowed position within the neck. One end is anchored within the wood. The other has a threaded adjustment nut. Tightening the nut draws the rod towards a straight line, which creates an upward bow in the middle of the neck. The adjustment nut can be oriented at either end of the neck, depening on the neck's construction.

Single Truss Rod Action

Benefits
  • Light weight
  • Vintage feel and tone
  • Less torque required for adjustment

Modern Double Truss Rods

A modern double truss rod is composed of two steel shafts that sit in a flat trench within the neck. Unlike the single rod design, the ends are not anchored within the wood. Instead, they are anchored to each other at one end. The other has a threaded adjustment nut. Tightening the nut pushes the ends of the rod downward, thereby creating bow in the neck. The adjustment nut can be oriented at either end of the neck, depending on the neck's construction.

Double Truss Rod Action

Benefits
  • Extremely stable, no seasonal adjustments are necessary
  • Increased mass for longer sustain, cleaner and clearer tones
  • The rod is not anchored to the wood, and therefore does not compress the wood lengthwise when tightened
The force exerted by the headstock end of the double rod is considerable. There must be a minimum 1/8" of wood below the rod end to prevent wood failure in this area. Thinning a neck beyond factory engineered dimensions is not recommended or covered under warranty.

The Side Adjust Mechanism

Warmoth Modern Construction guitar necks feature a Gotoh Side Adjust Mechanism*, which allows fine truss rod adjustments without removal of the neck. Initial setup is still accomplished using the main truss rod adjustment nut, but subsequent minor adjustments can be done via a small access hole on the side of the neck. Click the "More Information" link below for instructions on adjusting and resetting your Side Adjust Mechanism.

Side Adjust Mechanism
*The Side Adjust Mechanism is not available on left-handed, Baritone Conversion, Bass6, or 7-string necks.

Making Adjustments

The factory setting on a new neck is with the side adjustment mechanism centered within its operating range. To adjust your neck for the first time, use the following steps:

Side Adjust Diagram
  1. Tighten the heel-adjust nut (See A) until the fretboard is perfectly flat. At this point the side-adjust bolt (See B) should be recessed into the heel approximately 1/16" (2mm).
  2. Attach the neck and tune the strings to pitch.
  3. Check the neck relief. Detune strings and make the necessary relief adjustment using the side-adjust bolt (See B) and supplied allen wrench.
  4. Tune the strings to pitch. Repeat steps 3 and 4 as necessary.
  • Never loosen the side-adjust bolt so far that it protrudes from the side of the neck. If it is completely removed it may be very difficult to reinstall.
  • Never adjust the neck under full string tension - always de-tune the strings first.
  • Only moderate force is required to operate the side-adjust mechanism. It is possible to damage it if excessive force is applied after the bolt has stopped at the bottom of its travel (it would be recessed approximately 1/4" at this point). If the side-adjust bolt is recessed and there is a large amount of resistance, STOP and reset it as outlined below.
  • Fully tightening the side-adjuster so that it stops will also lock the action of the heel-adjust nut. Do not attempt to tighten the heel nut when the side mechanism is locked.
Reset Procedure

Most necessary relief adjustments can be accomplished using only the side-adjust. If you have completely tightened or loosened it and still need to make further adjustments, you may need to reset it by removing the neck and following the steps below:

  1. Completely loosen the truss rod heel-adjust nut.
  2. Turning clockwise, tighten side-adjust bolt until it stops.
  3. Back side-adjust bolt out 7 (seven) complete turns. This will center it in its best operating range.
  4. Tighten heel-adjust nut until fretboard is perfectly flat (has no forward curve).
  5. Attach neck and tune to pitch. Detune strings and make necessary relief adjustment with side-adjust bolt. Repeat as necessary.