I have found that feel is what really draws a player to a certain guitar. Asthetics may be what first catches one's eye but it is fit and feel that gives a player that "must have" syndrome. Fretboard radius is one of the subtle elements that contributes to the overall playability of a guitar. Here we will look at what fretboard radius is and why it matters.
How is Fretboard Radius Measured?
Common acoustic guitar fretboard radiuses are 10", 12", 16", and 20". The way to understand fretboard radius is to look at how the measurments are derived. Imagine two circles with radii of 10" and 20". Cut out a section from the side of each circle the width of the fretboard. The section from the 10" radius circle (black) has a bit more curvature than the 20" radius circle (grey).
The Effect on Playability.
As a general rule, a more curved fretboard is a bit more comfortable for barring or chording than a flatter one. The idea is that the board more closely fits the curvature of the fingers. The down side is that a more curved board makes bending notes more difficult and is likely to cause string buzz as the string is moved toward the center of the fret (which is higher than the edges.) A flatter board allows for lower action and easier bending without fret buzz. So, in general a more curved board is better for chording and a flatter board is better for single notes.
The strengths of different fretboard radiuses are combined by the use of a compound radius. With this type of board, the radius changes as the player moves from the nut up the scale. The advantage is to provide a more curved board at the lower frets where many players tend to play chords and a flatter board at the higher frets for easier lead work. This the best of both worlds and makes for a great playing guitar all the way up the neck. Bamburg Guitars are made with 11"/ 20" compound radius fretboards.
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