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
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.)