How to Read Your Guitar Neck: Relief and Back Bow

The neck is one of the most important parts of your guitar. It affects how it plays, how it sounds and how stable the tuning is, so being able to read it is worth learning. Today there is a beautiful Gibson Flying V on the bench, and it makes a good demonstration because the check works the same on everything.

The string is your straight edge

The quickest check there is: use the string itself. Fret it at the first fret and again up where the neck meets the body, which takes the nut and the saddle out of the equation, and the string becomes a perfect straight edge. It does not much matter whether your upper hand is at the twelfth or fifteenth fret. Then give the string a little tap around the seventh to ninth fret, which is where the relief lives.

A small click means there is a touch of relief under the string, and a touch is exactly what you want. You can check across all the strings if you like, though they will usually agree with each other, since ideally the string radius matches the fingerboard. Too much relief and the middle of the neck gets sloppy, with the action low at both ends and high in the middle. Not enough and you will often get fret buzz.

Why sighting the neck can fool you

Plenty of players sight down the neck like a rifle barrel, and you can often see a rise that way. But it can mislead you in both directions. Fret heights can be off so slightly that the eye will never catch it, and the wood can have rises that do not matter at all, because if the frets sitting in that wood are level, the playability is unaffected. You are playing the frets, not the timber. So sight it if you like, but trust the string and the straight edge over your eye.

Spotting back bow

A long ruler across the frets tells you the rest. If the ruler rocks, the neck has back bow, curving away from the strings, and the question becomes whether loosening the truss rod off brings the neck straight and lets relief back in. If it cannot, that is a different set of issues and a job for the bench. Duck down and look for light under the ruler too: a sliver of light in the middle means a touch of relief, which on this Flying V is pretty much right where you want it.

What to do with what you find

A neck reading is a diagnosis, not a repair. If yours shows too much relief, none at all, or rock under the ruler, the home setup check will tell you what else is going on, and a setup assessment at the shop turns it into a plan with a price before any work happens.

Common questions

How much relief should a guitar neck have?

Just a touch. Enough that the string clicks lightly when you tap it at the seventh fret while fretted at both ends. Too much and the middle of the neck goes sloppy, too little and you get fret buzz.

Is sighting down the neck a good way to check it?

It can show you a rise, but it can also mislead you. Fret heights can be off so slightly the eye misses it, and the wood can rise in places that do not affect playability at all if the frets are level. The string and a straight edge tell you more.

What does back bow mean?

The neck curving away from the strings instead of toward them, so it drops down past around the fifth fret. If a long ruler rocks on the frets, that is the tell. The fix depends on whether the truss rod can be loosened to bring relief back.

My neck has a hump but plays fine. Should I worry?

No. Rises in the wood only matter if they push frets out of level. If the frets are level, the playability is not affected, which is exactly why we check frets and wood separately.

Neck telling you something is off?

Bring your instrument into the shop during opening hours, no appointment needed. Assessments are free and we can usually do them while you’re here, so you leave knowing exactly what it needs. Hours and directions are on the contact page.

For the odd bit of advice from the bench, join the Repair Bench mailing list and get $25 off your next repair or setup.