Truss Rod Adjustment
“Thanks for the action adjustment- the guitar plays and sounds great!”
-A.D. Ithaca, NY
|Adjusting a Taylor Truss Rod. Taylor guitars come equipped with a truss rod that is adjustable at the headstock. Assuming that a guitar’s frets are level, most folks will find .003″ to .006″ of relief comfortable. Although some folks like more relief, exceeding .010″ of relief can have a noticeable impact on intonation.||Musicman Sting Ray Bass. The truss rod on this bass guitar is adjusted at the body-end of the neck. The truss rod nut has holes in it so the neck may be adjusted without removing the neck from the bass’s body.|
What does a truss-rod do?
Adjustable truss rods reinforce a guitar neck and give the owner some wiggle room to counter both changes in string tension and climate changes. Varying climate conditions and string tension will combine to bow a fretted stringed instrument’s neck. Fortunately most guitars are equipped with an adjustable truss rod. The adjustable truss rod is designed to counter the bowing of a neck with a few turns of a wrench. By tightening the nut on a truss rod the neck will straighten or over-bow (become convex) if overtightened.
|The Truss-Rod Nut on a Gibson is accessible at the headstock where it is hidden beneath a bell shaped plastic cover.||The Truss-Rod on a Martin guitar is adjusted from inside the guitar. This photo shows the end of the truss- rod and the truss rod nut before this new neck was set.|
Why is a truss-rod necessary?
Most truss rod adjustments are made necessary by the changes in relative humidity that come with seasonal changes in climate. Many players have a difficult time maintaining a consistent environment for their instrument of 50% relative humidity year round (the relative humidity that most fretted stringed instruments are built to sustain). Therefore it is quite common for instruments to require multiple truss rod adjustments in a given year to counter the effects that humidity changes have on an instrument’s neck.
|Fender Guitars of yesteryear (and reissue Fenders such as the one pictured above) have a truss rod nut which is accessed at the neck pocket end of the neck. Many contemporary Fender electric guitars and basses have a truss-rod which is adjusted from the headstock.||Larrivee Guitars have a truss-rod which is adjusted inside the guitar. On these instruments the truss rod is actually recessed into the neck block. Although this design is good for structural stability, it is difficult to adjust if you don’t have the special allen wrench that comes with each Larrivee from the factory.|
Will a truss-rod adjustment always straighten a neck?
Unfortunately the truss rod will not correct all bowing that guitar neck’s develop. If under-bowed (concave) enough, even the truss rod will not properly straighten the neck.
|Rickenbacker Bass . This bass guitar has two truss rods.|