Don't Fear the Truss Rod

I was chit-chatting with a good pal of mine recently and, as so often happens, our talk turned to guitars. I told him I’d mucked about with my Strat and had goofed-up the action pretty seriously. We pulled it out and after ten seconds he pronounced it “unplayable”.

I couldn’t disagree. It was awful. I mentioned that all it needed was a little truss-rod adjustment and he turned and looked at me in abject horror. He said, “I’m too scared to touch those.” Honestly, it wasn’t until recently that I felt any different.

The Basics

What the heck is a truss-rod for in the first place?

Most of us think of the neck of our guitars as being a straight line from the nut to where it joins the body. You can setup a guitar this way, but to avoid fret-buzz you would need to set the bridge high enough so that pressing the string against any fret would avoid touching any higher frets. Basically the angle of the strings has to be steeper than the angle of the neck.

This can make the action at the lower frets feel very different from the higher-frets. Some players don’t like this. So the solution is to bow the neck (ever so slightly) so that you can lower the bridge-height but still avoid fret-buzz.

Light-touch super-shredders typically run with pretty slight (if any) bowing in the neck and the shallowest string-angle they can get away with. The angular difference between the neck and strings is tiny, maybe a few millimeters on either end.

But if you’re much of a string-bender you’ll may find it hard to “get under” those strings and bend them. This is a good indicator that you need to adjust your truss-rod a bit to add a little bow to the neck.

Can you over-bow the neck? You betcha. You would be able to tell too because the string-action would feel unnaturally high in the middle of the neck (frets 9-15) but feel good everywhere else.

So how does a truss-rod work? The basic concept is pretty simple. Imagine two rods running the length of the neck: one closer to the fretboard, one closer to the back of the neck. One of those is threaded into a nut of some sort that allows you to change the length of one rod relative to the other.

The rods are attached to the neck so shortening the rod closer to the fretboard will make it more concave. Making them the same length should make the neck flat and making the top one longer will back-bow the neck into a convex shape.

 Gibsons require you to unscrew a cover-plate to get to the truss-rod bolt.

Gibsons require you to unscrew a cover-plate to get to the truss-rod bolt.

 My Strat has open access to the truss-rod from the headstock.

My Strat has open access to the truss-rod from the headstock.

 EVH guitars use a “wheel” design at the base of the neck. You can stick anything in the holes to rotate the wheel.

EVH guitars use a “wheel” design at the base of the neck. You can stick anything in the holes to rotate the wheel.

The adjustable rod has some kind of device you turn. On my American Standard Stratocaster, it’s an allen nut in the headstock. On my Gibsons the nut can be found under a detachable plate in the headstock. In my EVH guitars, there’s a wheel at the base of the neck where it joins the body. Different devices, but all doing the same thing.

Putting it Into Perspective

There isn’t necessarily a right or wrong way to adjust a truss-rod. It’s just one of many settings on a guitar that you can tweak to dial-in your playing preference. If you have your guitar professionally setup (something I recommend doing if you’ve never had it done), a good guitar tech will work with you and your playing style.

A lot of this is about personal preference, not meeting some mathematical ideal. That said, most manufacturers have recommended guidelines for setting up the action properly on a guitar. But an instrument like a Stratocaster has been played by so many different players with radically different styles that a one-size-fits-all setup makes no sense. I find it hard to believe that Yngwie Malmsteen has his Strats setup the same way Stevie Ray Vaughan did.

The other thing to understand is that a guitar is a very dynamic system. There are several variables that affect playability. String choice, nut height, bridge height, intonation and neck-relief are just some of the factors that affect how a guitar feels in your hands. Getting a guitar setup right takes a few iterations as one adjustment affects another.

The Takeaway

A quick online search for truss-rod adjustment will quickly yield a lot of results. It seems that nearly all of them are punctuated with terrifying warnings about ruining your guitar. Yes. This can happen. But if you don’t act like a big gorilla, you can safely experiment with truss-rod adjustment.

Everybody’s different. You may not be one of those people that likes working on their guitars. I get that. But if you are and you haven’t worked with truss-rods, don’t let fear and ignorance keep you from learning. There is a wealth of great information out there. One of my favorite books on the topic is Dan Erlewine’s The Guitar Player Repair Guide. Also, don’t be afraid to chat-up your local guitar-repair tech.

I found these four videos to be a great demonstration of how to properly setup the action for a Stratocaster. It covers more than just the truss-rod and does a good job explaining how all the setup factors work with each.. For other guitars you can take the same basic concepts.

You may find that a proper setup makes all the difference in how a guitar feels. I’m convinced that a lot of people fall out of love with their guitars simply because they aren’t setup right.

Now go forth and make that axe sing!