|What is fretboard radius?
Fretboard radius is simply the curve of the fretboard from side to side. This curve
is to make the fretboard more comfortable for the fretting hand. The radius is described
as a measurement such as 7.25", 9.5", 12" or 16". These measurements
tell you that the fretboard is a segment of a circle or cylinder, which has a radius, or
size of 7.25", 9.5", 12" or 16". The larger the radius, the larger the
circle, and the flatter the fretboard will be.
Quite simply, the smaller radius (which is more curved) is more
comfortable for playing (particularly barre) chords, while a larger, flatter radius is
better for low action, single-note playing and bending. The other important characteristic
of radius is that the flatter the radius, the lower the action can be. This is because
when you bend a string on a lower part of the fretboard such as your first or second
string, you are bending it towards the middle of the fretboard, which is higher than the
edges, so the notes will tend to "fret out" - buzz against the higher parts of
the fret, killing sustain.
Another important thing to note is that staggered polepiece
pickups (like vintage style single-coils) were originally designed for vintage Fender
guitars, which had a small 7.25" radius. These sometimes don't work well with flatter
radii, making the middle strings jump out much louder, particularly the G string (which
was also designed for wound strings). There is a workaround for this problem, which is to
keep the pickups set lower (further away from the strings), where the string-to-string
balance will even out. The downside to this workaround, is that you lose volume with the
pickups set lower. You should also be aware that there are "modern vintage"
pickups, which also have staggered polepieces
A fretboard that is a fixed width, but
has a radius of 16" (green line) is a lot flatter than a fretboard which has the same
width, with a 7.25" radius (blue line)
|Which fretboard radius is best?
Which radius is "best" tends to be a personal thing, you
should be asking "which is best for me?". Generally, most players are going to
prefer something between a 9.5" and a 12". Many players who play more
"lead-based" styles, or those needing lower action and more bending will
probably be happier with larger radii such as 16" or even 20". Ultimately this
is down to personal preference, which is largely based on the instruments we learned to
play on. The best thing you can do is play as many different guitars as possible (like we
need an excuse, right?), making note of which feel more comfortable to you. Bear in mind
that other factors such as neck thickness, fretboard thickness, scale length and even
finish do affect the feel of a neck, but the more time you spend playing different
instruments, the easier it will be to identify each factor.
|Examples of common radii
|Vintage Fender Stratocaster
|Modern Fender Stratocaster
|Guitars with LSR roller nuts
|Guitars with Floyd Rose locking nuts*
||10 - 12"
|Compound radius replacement necks
|USA Custom guitars
||7.25" - 9.5"
||10" - 16"
to the original and Schaller Floyd Rose models but not necessarily "licensed"
|Conical radius fretboards
Conical radius fretboards (commonly and incorrectly called "compound"
radius fretboards) are an attempt to get a "best of both worlds" between smaller
and larger radii. These fretboards have a radius which changes, they start out more curved
at the nut and gradually get flatter as you climb the neck, so each fret is a fraction
flatter than the one before it. While a normal fixed radius is a segment of a circle or
cylinder, a conical radius is actually a segment of a cone.
The idea is that players tend to bend higher up the neck and play
chords lower down. The larger radius higher up on the neck lets you get the action down
lower and still bend cleanly, while the smaller radius nearer the nut makes chording
easier. Warmoth make replacement
necks with a 10" - 16" conical (which they call "compound") radius,
but my favourites are the USA
Custom guitars, who make a 7.25" - 12". They also make the flatter 10"
- 16" or even a 10" - 12" (on request).
Compound radius fretboards
As already noted, fretboards billed as compound are often not compound, but
conical. A compound fretboard has one radius for part of the length, then changes abruptly
to another radius for the next part, instead of the smooth, gradual transition of a
conical fretboard. This may be as simple as a 10" radius from the nut to the 12th
fret, then changing to 16" for the remainder of the fretboard, or there could be
three or four radii involved.
A conical radius fretboard
Compound radius fret dressing
A trick often used to make smaller radius fingerboards better for
bending is to dress the frets from about the 10th or 12th fret with a flatter radius. This
essentially makes the fretboard compound without needing to remove the frets, dress the
fingerboard and refret again. The difference in height between the common guitar radii is
usually very small, so doing this properly means that very little of the fretwire needs to
be removed, which usually leaves plenty of life in the frets. So if you have a vintage (or
vintage reissue) Strat that you want to get a lower action without notes fretting out on
bends, this is a great option.
While at first thought it might seem as though the curve of the strings should
match that of the fretboard, this is not necessarily so. A flatter radius is usually
possible, as bending the middle strings usually pulls the strings to the lower sides of
the fretboard, where there is less chance of them fretting out. Try setting your nut
radius to match your fretboard and your bridge radius to be slightly flatter - effectively
giving your strings a compound radius. You will find this gives a much easier feel and a
To measure radius it is necessary to have a simple but specialised tool: a radius
gauge. Stewart McDonald have some nifty radius gauges that work without removing the strings and a set of understring radius gauges that are capable of measuring both the
fretboard and the string radius. If you are into making your own tools, there are
templates at Kinman