Fingerboard Radius

For Incidents Happen:

I was designing a guitar from scratch, and I needed to know how thick my fingerboard would have to be in order to acommodate a given radius. I came up with:

2h = 2r - [square root of (4r squared - W squared)]

Where:
h = height of the centre of the board above the edges
r = radius of the fingerboard
W = Width of the fingerboard


For everybody:

What's the best radius for your style of playing, and why?

I checked the websites and i have a better idea now at least...

Fender Fingerboard Radius: 9.5"

Guild Fingerboard Radius: 12"

i'll post more as i find them

If you want to know the radius of one of your guitars, take it in to a repair shop, and have a tech measure it. They use pre-cut gauges like the ones here.

Also, be aware that the radius is different on different models, or even different years of the same model, especially Fenders. To make things even more confusing, a lot of newer guitars are built with a fretboard radius that changes along the length of the board.

Just to complicate matters the radius may be different at the bridge end of your neck and at the nut end (Composite necks) as if life wasn't complicated enough ! I got a really good book by Dan Erlewine called the Guitarplayer repair guide and he covers this and other topics in some detail..... 23 bucks well spent ! He is the same dude that hosts the stewmac guitar wiring video I was banging on about earlier

yeah, and i understand that, my Squier strat is fatter at the neck then it is at the peghead (21 fret to 1st fret), making the radius larger, but where do they do the measuring then?

Originally posted by Incidents Happen
...my Squier strat is fatter at the neck then it is at the peghead (21 fret to 1st fret), making the radius larger...

Not necessarily. The width of the fretboard does not determine the radius. The compound radius necks do have a longer radius at the body end of the neck, but most guitars have a constant radius along the full length of the fretboard.

Most fretboards are made with a jig that swings the material across the face of a belt sander. The surface radius is determined by the distance from the jig pivot to the sander. Older Fenders had a short radius, sometimes as small as 6", to make them easier to play. For bluesmen, and other string-benders, this was too much of a good thing, because bent notes at the high end of the neck would often 'fret out' because there was too much curve to the surface. Most Gibsons had a radius of about 10" or 12", which was much less likely to fret out on bends. Compound radius necks have a smaller radius at the nut, and gradually flatten out to a larger radius at the body end.

I like a 12" radius, seems to be about the best all round for me, round enough to play barre chords cleanly, flat enough for a low action and clean bends and most accoustic guitars have a radius in that neighborhood so I don't feel uncomfortable when I switch back and forth. I have one guitar with a 15" radius, it's alright, the fretboard is fairly wide and it's OK for what I use it for, but for me 12" seems to be right, given a choice between a steeper or flatter radius, I would probaly choose steeper, never tried a compound radius, maybe thats the best of both worlds?

nah its not that great, at least mine isnt..

I'm talking a compound radius of 10"-16" which takes a fretboard designed for that purpose, reworking the radius of a factory board you might get a 3"radius change, noticeable, yes, but not quite the same........

ooooooooooh, yeah mine doesnt make that big of a difference.

It goes from probably 9.5 to 10.5 or 11 at the most...

But if you've ever seen a neck where it stays the exact same throughout, they do look sharp (check out garcia's "Tiger"), in my opinion at least...