What A Relief!

When I was in high school, a good friend of mine snapped the neck of his bass guitar while trying to adjust the truss rod.  Since then, I have learned a great deal about how to maintain my own instruments, but because of this shocking incident during my adolescence where my friend snapped his neck simply by turning an allen key, I have always avoided any attempt at truss rod adjustments.  That is, until recently.

Thanks to lockdown caused by the corona virus, I have been unable to take my guitars in for regular maintenance the way that I would have in the past.  This means learning how to do some things that I might not normally do on my own.  

I bought a guitar in the fall of 2020, and immediately replaced the 10 gauge strings that most guitars come equipped with to my preferred string and brand, D'Addario balanced tension 11-50.

Usually when you change the gauge of strings on a guitar it's a good idea to adjust the truss rod.  So I found myself in a situation where I had nothing but time, and no better option than to learn to adjust the truss rod on my own.

What Is A Truss Rod?

A truss rod is a steel bar that runs through the neck of a guitar.  Often times, the end of the truss rod is visible at either the headstock of the guitar, or at the end of the fretboard where the neck meets the body. 
Gibson Truss Rod Cover
Gibson, who applied for the patent for the truss rod in 1921, uses a bell shaped plastic cover to hide the access point for the truss rod on most of their electric guitar models.

Fender Truss Rod
On many modern Fender style guitars the truss rod can be seen just behind the nut of the guitar, at the headstock.
Vintage Style Truss Rod
On certain older and vintage style guitars the truss rod is accessible at the end of the neck where it meets the body.  On these guitars, the neck must be removed in order to adjust the truss rod.

While the truss rod is only visible at one end of the neck, it is actually a steel bar that runs all the way down the neck on the inside.  Some very well built classical guitars don't use truss rods, but one of the reasons for this is that classical guitars use nylon strings which do not put the same amount of tension on the wood of the neck as steel strings do.  If your steel string guitar did not have a truss rod, over time the wood of the neck would become warped beyond repair by the tension of the strings.  

The truss rod counteracts the tension placed on the wood of the neck by the strings.  Tightening the truss rod (turning it to the right) will straighten the neck out, and loosening the truss rod (turning it to the left) will allow the tension of the strings to act on the neck more, causing a slight forward bend (known as relief) in the neck.  

Why Would You Need To Adjust The Truss Rod?

There are a few reasons why you might want to adjust the truss rod.  The first reason has to do with changes in atmospheric conditions such as humidity.  A drastic change in humidity can affect the relief in your neck, and adjusting the truss rod can help to fix that.  

Changing the gauge of strings you are using on your guitar can also affect the relief in your neck, and it can also affect how much relief you may want to have in your neck.  Thicker strings have a wider vibration, and putting thicker strings on your guitar without loosening the truss rod to add a bit of neck relief can cause the strings to vibrate slightly against the frets in the middle of the neck, giving off a slight sitar like buzzing.  Loosening the truss rod to allow for more relief in the neck can allow thicker gauge strings enough room to vibrate uninterrupted, without having to raise your action unplayably high to get rid of the buzzing.  

How To Adjust The Truss Rod

As you may or may not know, I am not a guitar tech.  Therefore, I'm not sure I necessarily have the best advice on how to adjust your truss rod, but I have been able to find some great resources online that do have helpful advice. 

This video by Gibson gives some great practical advice on how to adjust your truss rod.  Some of the tips in this video are widely known, and are worth reiterating:

-When adjusting the truss rod, you should really only work in 1/4 turn increments.
-If you don't have a feeler gauge, use a business card instead to measure the distance from the top of the fret to the string.

In order to adjust your truss rod, there are some tools you will need to have around:

You will need to have a capo in order to help you to measure the relief in your neck.  Literally any capo will do, but if you don't have a capo I highly recommend these Kyser Capos, they're great capos. 

You will need to verify that your guitar is in tune during the process of adjusting your truss rod.  Again, any tuner will do, but I recommend these low cost D'Addario headstock tuners.  I use them all the time and I find them to be very accurate.

Allen Key/Socket Wrench/Multi-tool
To take off the truss rod cover (if there is one) and to turn the actual truss rod, you will need a combination of simple things.  Truss rod covers usually require a phillips head screwdriver, and to turn the truss rod you will need a socket wrench or a hex key or in some cases an allen key.  Thankfully there are multi tools on the market that you can keep in your guitar case that will perform all of these functions.

Feeler Gauges
While you can use a business card or a sheet of paper to measure the relief in your neck, a more accurate and easier way of making this measurement is to use feeler gauges.  These gauges are super small and can be kept in your guitar case.

Thanks so much for checking out my thoughts on this subject, and as always if you have any questions or concerns feel free to reach out or comment.  Thank you for making me a super small part of your journey with the guitar, its something that I never take for granted.

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