What's the deal with necks and fretboards?

[Eric***]

So I sometimes see radii measurements where it seems to refer to the neck, like '12" radius neck' or something, like here for instance.

Is this actually referring to the fretboard? I understand the whole idea of the arc of a circle with radius X for a fretboard, but does this translate to the neck itself at all? Is there any way to measure necks other than the letter designation (C, U, D, V) for shape and general "thick" or "not thick" descriptors for the thickness of it?

Just trying to understand a bit more. I'll probably ask something about width in here at some point too...

[Tonz]

If you have an expensive custom neck made for you, they take different measurements of your hands so the neck would be perfect for your hand.
The letter designation is just a template to meet with the tastes of different players, the same goes for width and F.B. radius.

[rdvstrat]

(See chart) radius in inch or metric, chord is width of neck. Curved line above the chord line is neck curvature. The longer the radius for the same neck width, the flatter the neck is/feels.
7.5" -> Vintage Fender - easy chording but strings can be too easily pushed off the sides of the fretboard during soloing on the higher frets.
12" -> Gibson - faster soloing, less comfortable chording.
The above comparisons are in general.
I like 12" radius. 7.5" gives me a headache.

C, U, D, V, etc. usually refers to the back of the neck, the shape of the neck wood itself. The shape of the letter indicates the shape of the cross section of the neck which your hand would feel. i.e, a V feel, a D feel. I think with Fender the C designation is unique to Fender history. I think I read that Fender graded necks A, B, C etc. referring to sizes/neck widths etc. to help in assembly/optioning.
The Warmoth site has some info on their neck dimensions/designations. You could try buying an oversized unfinished neck and filing/sanding it down to what you like.

[ZMAN]

I found this this little piece it might help.
http://www.guitartechcraig.com/techneck/necks.htm
Guitar players come in all shapes and sizes, (of hands that is), and a certain profile, (C, D, U, V) Will fit a persons hands. The sames goes for the style a person plays. A lot of bending of notes usually requires a 9.5 to 12 inch radius.
Most guitars are made in a one size fits all to appeal to the majority of buyers.
That is why a lot of guys pick up a guitar and it just doesn't feel right. It doesn't have the correct radius or profile to fit their hands or style.
In the beginning they measured the shape of the neck profile with a template, and each neck could be slightly different within certain tolerances.
Now with the C and C machines they are exact.
I guess what you have to do is play a guitar then find out what the radius is and the profile. Then you can tell what your favourite is.
Most modern guitars will tell you right up front what they are.
Signature guitars will have the Radius, and profile that the Artist likes best.
Vintage spec will be the Radius and profile they were made "in the day".
As a General rule of thumb, Fender will usually have a 9.5 Radius in the more modern guitars and 7.5 in the Vintage reissues etc.
Gibson is usually a 12 inch on their boards.
Knowing what the best fit for you in radius and profile, especially when buying online or sight unseen, can save you a lot of grief.

[Eric***]

I found this this little piece it might help.
http://www.guitartechcraig.com/techneck/necks.htm
Guitar players come in all shapes and sizes, (of hands that is), and a certain profile, (C, D, U, V) Will fit a persons hands. The sames goes for the style a person plays. A lot of bending of notes usually requires a 9.5 to 12 inch radius.
Most guitars are made in a one size fits all to appeal to the majority of buyers.
That is why a lot of guys pick up a guitar and it just doesn't feel right. It doesn't have the correct radius or profile to fit their hands or style.
In the beginning they measured the shape of the neck profile with a template, and each neck could be slightly different within certain tolerances.
Now with the C and C machines they are exact.
I guess what you have to do is play a guitar then find out what the radius is and the profile. Then you can tell what your favourite is.
Most modern guitars will tell you right up front what they are.
Signature guitars will have the Radius, and profile that the Artist likes best.
Vintage spec will be the Radius and profile they were made "in the day".
As a General rule of thumb, Fender will usually have a 9.5 Radius in the more modern guitars and 7.5 in the Vintage reissues etc.
Gibson is usually a 12 inch on their boards.
Knowing what the best fit for you in radius and profile, especially when buying online or sight unseen, can save you a lot of grief.

Cool. Thanks for the link.

So there's no real way to assign a number to a neck I take it? When they say '13.7" (350mm) radius neck' like in the ad for the Agile I own, does that actually refer to the fretboard radius?

I'm trying to figure out what the neck profile, thickness, and radii are of the guitars I own so that I can figure out what I like, but first I have to get my terminology down. Is there any good way to figure out what the neck profile is of a guitar you own?

[bcdon***]

Nice post, rdvstrat. And welcome to The Fret!

7.5" -> Vintage Fender - easy chording but strings can be too easily pushed off the sides of the fretboard during soloing on the higher frets.
12" -> Gibson - faster soloing, less comfortable chording.
The above comparisons are in general.
I like 12" radius. 7.5" gives me a headache.

[rdvstrat]

Thanks bcdon

[markb]

Eric, the radius refers to the fingerboard and not the back of the neck. Neck profile is more of a "see what it looks like" deal. The letters C, D, U and V are often used to describe necks. A C neck is a smooth curve with no shoulder found on most modern Fenders. A D neck has more of a shoulder and a U neck has a pronounced deep shoulder. A V neck takes material from the sides of the neck but adds depth with the pointed V profile.

The profile is just about how it sits in your hand as mentioned above.

[tjcurtin1]

Weird. I was thinking about this in the shower this morning - particularly the letter designations for neck shape. Nice to get that link, Zman!

[Eric***]

Eric, the radius refers to the fingerboard and not the back of the neck. Neck profile is more of a "see what it looks like" deal. The letters C, D, U and V are often used to describe necks. A C neck is a smooth curve with no shoulder found on most modern Fenders. A D neck has more of a shoulder and a U neck has a pronounced deep shoulder. A V neck takes material from the sides of the neck but adds depth with the pointed V profile.

The profile is just about how it sits in your hand as mentioned above.

That's what I was looking for -- thanks very much. I guess I'll keep my eye out for different profiles now to see if I can figure out how the different ones feel.

[marnold***]

When they say '13.7" (350mm) radius neck' like in the ad for the Agile I own, does that actually refer to the fretboard radius?

Yes.