Go into a guitar store and pick up a few random guitars of different designs and brands. Ever wonder why some guitars just feel ‘right’ while others feel just plain weird? Often it’s at least partially down to the radius of the fretboard. This refers to how flat or curved the fretboard the frets are. Different roundnesses provide different playing feels, and some are better suited to particular styles than others are. But there really isn’t such a thing as a ‘bad’ radius, just ‘the right radius for you.’ With that in mind, let’s look at what each popular radius actually is, and what each is best suited for.
When you see the radius mentioned on a spec sheet, it’s usually written in inches – although you may see in expressed in millimetres instead. Smaller numbers indicate rounder radii, while higher ones indicate flatter fretboards. For example, original Stratocasters have a 7.25″ radius (184.15mm), which is very curvy. It makes chording easier (especially barre chords), but if your string height is low there’s a risk of notes ‘choking out’ on higher frets if you bend them too far.
Conversely, a flatter radius like 18″ is much easier to bend with, and many players feel that a flatter fretboard is far better suited to advanced techniques like string skipping, sweep picking and general all-round shredding. That doesn’t mean you can’t shred on a Strat, of course, but the feel is definitely different.
There are two ways of reaching a compromise between a more bend-friendly flat radius and a chord-happy one. The first is to simply use a mid point. Some guitars have a 9.5″ radius, which is noticeably flatter than 7.25″ but still a little curvy. Others, such as the majority of Gibsons, have a 12″ radius, which is flatter again, but not as plank-like as an 18″ one. This strikes the perfect balance between easy string bendability and comfortable chording: chord techniques tend to favor rounder radii, while flatter fretboards are known for being shred machines. And rounder radii can choke up during string bends on guitars with lower action. So a 12″ radius strikes and ideal middle ground.
The other option is a compound radius fretboard, as found on the 2012 Les Paul Standard. This is a neck where the radius is nice and flat at the higher frets, but becomes progressively curved as you make your way towards the nut. It offers the absolute best of both worlds: a flat enough surface for crazy wide bends at the widdly end of the neck, and a curvy one for comfortable chording down at the other end. In the case of the Standard, the fretboard starts at a curvy 10″ at the nut end for easier chording, progressing gradually to a shred-friendly 16″ at the other end.
Of course, a scalloped fretboard is something different entirely, and can have any kind of radius in addition to the scooped-out fretboard surface between each fret. Read more about scalloped fretboards here.
What radius do you prefer?