Fingerboard Radius Part 1

The following article is coutosy of Tony Pasko who writes GEAR 411 at The Rock House Method.

Have you ever wondered why you play faster on certain guitars than others? Or why on some guitars you can bend easier? Or that some scales you mess up on all the time, seem easier on another guitar? If you have run across this; you are not alone, and there is a very simple answer. Fingerboard Radius.

Now this isn’t the only answer to these questions. For this first part of a series that will help you understand that the guitar or bass you play has something to do with how well you play in general. This series might also help you see that maybe you are not playing the right guitar for the style of music you want to excel in. 


What is fingerboard radius? It’s the playing surface of the guitar neck. It’s usually curved across the width of the neck, and the purpose of this curve is to accommodate the natural ergonomic shape of your fingers when they are in playing position. Comfort is certainly a major factor in selecting a guitar but it is not the only factor; neck shape, fret size, and scale length are all major factors in how the guitars feel and play. Musical style is another factor and the fingerboard radius must allow you to play the style of music you prefer, but how do you know what’s the right one for you?

The curve on the fretboard (Radius) can very from round to almost flat, and in some cases like in classical guitars the radius scoops in slightly. There is a number system that let’s you know how round the fretboard radius is on your neck. Let’s start with a vintage strat which starts out at a 10” at the nut and some flatten out to about a 12” on average, what does this mean?

The lower the number the rounder the radius or curve, so the neck is pretty round at the nut, and as it goes to a 12” which is still round but flatter than the nut and single-cut guitars are usually flatter and start with a 12” radius at the nut. Modern style guitars let’s say with locking tremolo systems, the radius at the nut can go from a 12” to a 14” and flatten out to a 16” which is pretty flat.

Compound Radius Fingerboards

Here is another option that some guitar players over look. This concept is to improve both comfort and playability. You know how comfortable a vintage strat neck is for rhythm work and chording, but without uncomfortably high action, string bending is not often an option the strings "Fret-Out".

To achieve low action and no buzzing, many necks resort to a 16" fingerboard radius. This certainly works, but the comfort factor is lost. Compound radius makes the fretboard conical. This retains a tighter radius in the area commonly used for rhythm and chording, while flattening the area used for bending and lead playing.

Some use a 10" radius at the nut for both comfort and compatibility with a Floyd Rose locking nut, and a 16" radius at the heel has proven to afford 2-1/2 step bends with action below a 16th of an inch. (These specs vary)

This concept is something to consider. I have played many guitars with a compound radius fretboard and you don’t really notice the changing radius. It is easy to play on and very comfortable.

Why isn’t compound radius an option offered on more guitars? Compared to a conventional single radius neck, the compound radius is far more difficult and time consuming to produce, but some manufacturers like Jackson, Carvin, Fender, and Warmoth all offer this as an option.

I will say this is an option that will make a noticeable difference in your playing. Will it improve in your playing speed? It might because the fretboard follows the natural flow of your hand as you play up the neck. String bending was easier and more comfortable and heavier strings felt lighter and rang out longer.

Why so many different radius sizes? Because our hands are all different, and the radius is to accommodate many different size hands. Some of us have small hands and short fingers while others have big hands and long fingers, this is a major factor to consider when picking out a guitar. The radius affects how your fingers move on the fretboard, thus affecting the way you play.

The type of bridge on the guitar is a factor, and this will also affect the radius. Standard tremolo systems and hard tails can be adjusted to the radius of the fretboard, and some locking tremolo systems and tune-o-matic bridges are fixed. What does that mean? Identifying the type of bridge on the guitar is an indicator of what the radius is, not exactly, but it will get you in the ballpark.

All you need to do is look down the neck of the guitar and you can see the curve. The radius of the fretboard and bridge should follow the same curve. If not? Take it to your local music store or repair shop to be adjusted or shimmed.

As you can see I am leaving this very open ended because there are so many different factors and it’s really up to you on what is right, but experiment and try different things, you might find out that something else is out there that fits you better.

I will say that I am a strong believer in having many different types of guitars and basses. I stopped looking a long time ago for that one guitar that did everything, why? One guitar can’t do it all. When I want to play like Hendrix? Can’t do it on a Les Paul, when I want to Rock like Angus, can’t do it on a strat, and when I’m in my Van Halen mood, again neither of those guitars will work, I need a Floyd Rose tremolo.

Remember that the fingerboard radius affected how those guys played, and to emulate our heroes, sometimes we need the same tools they used. The radius of the fretboard is only one small part of the overall formula, but it does affect how you play and that means a lot.

The next part of this series we will dive into the other major factor. Neck Shape, combined with fretboard radius will help you see that one affects the other more than you know, and what you like about your guitar neck might not have as much to do with the shape, but a combination of many parts.

Fret size, scale length, strings, truss rod, and wood type are all apart of this ongoing series.

Thanks for listening and I look forward to your feedback, and I hope this sparks some discussions so we all can share our opinions and expertise.


Tony J. Pasko

P.S. For more info check out www.warmoth.com

Part 2 link - Fingerboard Radius Part 2

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Anonymous said...

"Let’s start with a vintage strat which starts out at a 10” at the nut and some flatten out to about a 12” on average, what does this mean?"

Um no...vintage Strats have a 7.25" radius.

sarge1875 said...

I e mailed Tony P today and he wanted me to respond that "Yeah, some did have a 7.25" radius. Doesn't change the fact that the lower number means the radius is rounder. That's all I'm saying. I'm just giving an average."

He also thought it would be good to mention that there are many vintage years of a strat and they all have a different radius. A '54 strat is different from a '62.

Stormy Maverick said...

Love the technical stuff Tony puts out there for us! Keep it coming.