CF necks - truss rod / no truss rod

[Earl49]

Backbow is generally considered to be the neck bending backward, lowering the strings (laying against the frets in extreme cases) and fret buzz results. Forward bow is where the neck curves up under string tension, allowing for string clearance. The truss rod offsets this tension and controls the degree of curvature, which we call relief.

Since the vibrating string moves in an arc, some clearance is needed to avoid the string hitting frets somewhere along the neck, causing buzz. Sometimes you can get away with a nearly flat neck if the fretwork is perfect and the nut and saddle are high enough, but this won't give you the easiest playing feel. Relief of 0.004" to 0.008" is often considered to be the normal range. A standard piece of 20 pound copy paper is about 4 thousandths or 0.004" thick, so there is not a lot of clearance. Capo at the first fret and press down at the body join fret, then if a thickness of paper fits at the 7th fret, relief is right but lowish. A finger picker might want 0.004" and a moderate or heavy flatpicker / strummer might want 0.008" relief.

Guitaluva has it right. Some CA guitars toward the end of production - right before the original company's demise - had neck set issues that really cannot be fixed. Early ones were fine, and we haven't heard reports of problems since Peavey brought CA guitars back to the market.

[jonfields45]

I owned four pre-Peavey CAs (Cargo, Dreadnought, OX and GX) and one post-Peavey Cargo. The OX had a marginal neck angle with more relief than I would normally like to see. It was still quite playable. Peavey did make a big noise about adding stiffening rods to the CA necks before ramping their production and that old problem is not relevant to Peavey CAs or most original CAs. Blackbird also redesigned their CF necks in their early days by adding stiffening rods too. There is a learning experience manufacturing any new product.