How to Correct a Back Bow on an Acoustic Guitar

back-bow

If your guitar neck has a back bow, then there will be a high spot in the middle of your neck will. A back bowed neck can cause all sorts of intonation and playing problems, including fret buzz, so if you have one, it’s the first thing you’ll want to fix as you run you guitar through a setup.

The normal cause of back bow is an over-tightened truss rod. That is, your truss rod is too tight and is exerting too much pressure on the neck. In order to remedy this, you’ll want to loosen the truss rod and allow the tension exerted by the strings to pull the neck forward.

The Adjustment

Now it’s time for the actual adjustment. Use a hex key or socket wrench to do this. (The type of tool you use here depends on the truss rod in your guitar).

1. First, if you have a truss rod cover, you’ll want to remove it.

truss_cover

2. Now, loosen your truss rod with your hex key or socket wrench by turning it a quarter turn or so counter clockwise.

tighten_trussrod2

3. Use a straight edge to see if you were able to remove the back bow from your neck. (“Physical Assessment,” in the previous step.)

4. Continue steps 1 and 2 until the back bow in your neck is gone. (Be careful not to over do it). If you loosen it to much, to the point where theres no tension on the truss rod at all, the nut your tightening could begin to rattle when playing. So make sure the nut is left snug.  If the neck still has a back bow, you have more serious issues. You either heat up the neck and force it into a straight position or pull the frets or  sand the fingerboard level and refret. These jobs are for another show.

5. Now you’ll want to do one last check to make sure you didn’t loosen your truss rod too much (this would cause a forward bow). Repeat the “Physical Assessment,” explained in the previous step.

6. Okay, last step. Do one more visual assessment on you neck to be sure you’ve completely eliminated any back bow and haven’t caused any other neck problems.

Completion

Now that you’re done adjusting your neck, you can continue running through the setup.

- Tip -

Some luthiers suggest letting the neck rest overnight before continuing the setup. This will allow the neck to settle into its new tension position.

Next Step –>

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How a Truss Rod Works

truss_tighten

Not quite sure how that steel rod in your guitar neck works? The video clip below should explain things.The same principles apply to electric guitars, bass guitars and acoustic guitars with truss rods.

As the clip shows, a guitar truss rod is a steel rod that runs down the length of most guitar and bass necks (with the exception of classical guitars). Loosening it or tightening it can help to straighten out a bowed neck.

The Adjustments

- Loosening a truss rod relieves tension on the neck and allows the pressure exerted by the strings to pull the neck forward and correct any bow, in most cases.

- Tightening a truss rod increases pressure and can straighten a forward-bowed neck by increasing its resistance to the pressure exerted by the strings.

Accessing the Truss Rod

There is a lot of variation in terms of the access point to a truss rod. In general, most Acoustic guitar truss rods can be accessed through the sound hole of the guitar (although some may be accessed at the head of the guitar). Most electric and bass guitar truss rods can be accessed at the head of the guitar.

Straightening a bowed neck is the first step in any guitar or bass setup and is an essential element in gaining the best sound and feel possible from your instrument. The clip above was taken from Fret MD: Acoustic Guitar and Bass Setup and Maintenance and was narrated by the video’s host, Al Markasky.


How to Correct a Back Bow on a Bass

If your bass has a back bow in it’s neck, this means that the neck is arching away form the bridge of your bass. The normal cause of back bow is an over-tightened truss rod. That is, your truss rod is too tight and is exerting too much pressure on the neck. In order to fix a back bow, you’ll want to loosen the tension of your truss rod and allow the tension of the strings to pull your neck forward.

The Adjustment
Now it’s time for the actual adjustment. Use an alan wrench, hex key or socket wrench to do this. (The type of tool you use here depends on the truss rod in your bass).
1. First, if you have a truss rod cover, you’ll want to remove it.

truss_cover
2. Now, loosen use your truss rod with your alan wrench, hex key or socket wrench by turning it a quarter turn or so counter clockwise.
3. Use a straight edge to see if you were able to remove the back bow from your neck. (Step 3 in the assessment)
4. Continue steps 1 and 2 until the back bow in your neck is gone. (Be careful not to over do it. over loosening or over
5. Now you’ll want to do one last check to make sure you didn’t loosen your truss rod too much (this would cause a forward bow). Repeat step 4 of the assessment.
6. Okay, last step. Do one more visual assessment on you neck to be sure you’ve completely eliminated any back bow and haven’t caused any other neck problems.
Completion
Now you’re done adjusting your neck. You can continue the setup. Some luthiers, including Al Markasky, suggest letting the neck rest over night before continuing the setup. This will allow the neck to settle in it’s new tension position before continuing a setup.

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(1 of 3) Neck Assessment and Adjustment on an Acoustic Guitar

Tools

  • 12 or 15 in. Metal Straight Edge
  • Alan Wrench, Hex Key or Socket Wrench
  • Light Piece of Paper, Paper Towel or light cloth to use as a backdrop
  • Phillips Head Screwdriver (if your guitar has a truss rod cover)

A bowed neck can cause all sorts of problems. Poor intonation and fret buzz are among the top two. In this tutorial you’ll learn how to check the straightness of your neck and make adjustments based on your diagnosis.

Visual Assessment

1. First, hold your guitar up and sight down the treble and bass sides of your instrument’s neck checking for any signs of a bow.

sitedown_neck

Physical Assessment

2. Place a straight edge flat on the frets in the middle of your guitar’s neck between the E and A strings. Now check for any rocking by alternating slight pressure between the ends of the ruler. If the ruler rocks up and down at all, then you probably have a forward bow in your neck.

neck

4. Now check for any signs of a gap underneath the frets. You should use a white piece of paper or a light colored cloth as the back drop for this. If you notice a gap between some of the frets and the bottom of the ruler then you probably have a forward bow.

neck_backdrop

5. Repeat Steps 3 and 4, first between the D and G strings and then between the B and E strings.

Now you should have a good picture of the overall health of your guitar’s neck. If you assessed your neck’s condition correctly, you should know if you have a back bow or a forward bow; or if you’re lucky and your neck is perfectly straight.

Adjustment

7. This is where the variations start in your setup. During your visual assessment you should have determined whether your neck has a back bow or a forward bow.  If you neck has a bow in it, click on one of the links below to determine how to correct it.

How to Fix a Back Bow –>

How to Fix a Forward Bow –>

Next Step –>



How to Fix Back Bow on an Electric Guitar

A back bowed neck can cause all sorts of problems, so if you have one, it’s the first thing you’ll want to fix as you run your guitar through a setup. The good news is, a back bow is usually easy to fix. In this tutorial I’ll explain the full process of detecting and fixing a back bow, from start to finish.

Cause

The normal cause of back bow is an over-tightened truss rod. If your truss rod is too tight then the neck will usually bow backwards. In order to fix this, you’ll want to loosen the truss rod and relieve the pressure it’s exerting on the neck. You can do this by turning the truss rod nut (or bolt) counter clockwise with a hex key or socket wrench. As you do this, the tension exerted by the strings will pull the neck forward (this is why it’s important to keep your guitar tuned to pitch when you’re trying to straighten out your neck).

The Adjustment

Now it’s time for the actual adjustment. Use a hex key or socket wrench to do this. (The type of tool you use here depends on the type of truss rod in your guitar).

1. First of all, obey the golden rule of setup and TUNE YOUR GUITAR TO PITCH. (E, A, D, G, B, E)

1b. If you have a truss rod cover, you’ll want to remove it now.

2. Loosen your truss rod using a hex key or socket wrench by turning it a quarter turn or so counter clockwise (counter clockwise = to the left).

3. Use a straight edge to see if you were able to remove the back bow from your neck. (If you don’t know how to do this click here ).

4. Continue steps 1 through 3 until the back bow in your neck is gone. (Be careful not to over do it. over loosening or over tightening a truss rod could cause it to snap, and you don’t want that to happen.)

5. Now you’ll want to do one last check to make sure you didn’t loosen your truss rod too much (this would cause a forward bow). Repeat step 4, above. If you loosen your truss rod too much, then you might notice a forward bow in the neck. This is easy to fix. Just repeat steps 1 through 3 above, but tighten the truss rod by turning it to the right this time. (Remember the rhyme: “lefty loosey, righty tighty.)

6. Okay, last step. Do one more visual assessment on you neck to be sure you’ve completely eliminated any back bow and haven’t caused any other neck problems.

Complete?

Now that you’ve fixed the back bow in your guitar’s neck, you’ve completely changed your guitar. You’ll want to continue running your guitar through a setup at this point. This will help eliminate any other problems that straightening your guitar’s neck might have caused or may cause in the future.

WARNING! – Running your guitar through a setup could cause it to sound and play better than it ever has before.

Continue Setup –>

- Tip -

Some luthiers suggest letting the neck rest overnight before continuing the setup. This will allow the neck to settle into its new tension position.

If you found this tutorial helpful please leave a comment below, bookmark this site or use the “Share This” link below to share this tutorial with your friends. – You can also find out out how to make you guitar sound 100% better by buying one of our DVDs. All purchases come with a 100% satisfaction guarantee. See Details–>

You can also continue this tutorial and find out how to run your guitar through a setup, by clicking the link below.

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(1 of 5) How to Assess and Adjust a Bass Neck

bassfeeler

Tools

  • 12 or 15 in. (30cm or 40cm) Metal Straight Edge
  • Hex Key or Socket Wrench
  • Light Piece of Paper, Paper Towel or light cloth to use as a backdrop
  • Phillips Head Screwdriver (if your bass has a truss rod cover)

A bowed neck can cause all sorts of problems. Poor intonation and fret buzz are among the top two. In this tutorial you’ll learn how to check the straightness of your neck and make adjustments based on your diagnosis.

Visual Assessment

1. First, hold your guitar up and sight down the treble and bass sides of your instrument’s neck checking for any signs of a bow.

Physical Assessment and Diagnosis

electric_straightedge

2. Place a straight edge flat on the frets in the middle of your bass’ neck between the E and A strings. Now check for any rocking by alternating slight pressure downward on the opposite ends of the ruler.

Diagnosis: If the ruler rocks up and down at all, your guitar probably has a back bow.

4. Now check for any signs of a gap underneath the frets. (You should use a white piece of paper or a light colored cloth as the back drop when you do this.)

Diagnosis: If you notice a gap between some of the frets and the bottom of the ruler then you probably have a back bow.

5. Repeat Steps 3 and 4, first between the D and G strings, and then between the B and E strings.

Once you complete your assessment you should have a good picture of the overall health of your guitar’s neck. If you were able to assess your neck’s condition correctly, then you will know whether you have a back bow or a forward bow; or if you’re lucky and your neck is perfectly straight.

Adjustment

7. During your assessment you should have been able to determined whether your neck has a back bow or a forward bow. Click one of the links below to determine how to correct a back bow or forward bow. (If your neck has no bow in it at all then you should move on to the next step.)

Correct Bass Neck Forward Bow –>

Correct Bass Neck Back Bow –>

Next Step –>