Truss rod in a nylon crossover?

[Quickstep192]

Would you put a truss rod in a nylon crossover that had 14 frets to the neck?

I know truss rods aren't usually put in classical guitars, but is this one of those better to have it and not need it kind of things?

Thanks for opinions, wisdom and experiences

[Rodger Knox]

I would not, but that doesn't mean it's a bad idea. I'd build the neck stiff enough that it wouldn't flex any under string tension, and build the relief and fallaway into the fretboard. Nylon string guitars don't have trussrods for two reasons, they don't really need them and they add weight to the neck.

It might be nice to be able to dial in the relief, but I don't see that as necessary.

[Quickstep192]

Dialing in the neck relief was the idea behind it, but perhaps being able to dial in the string height isn't as important with strings that are easier to fret.

[mb propsom]

I just finished a 000 nylon string "hybrid" with a double action rod in the neck. After a certain period of time, even with the reduced tension of nylon strings, there's still the potential for increased relief in the neck. I like to have the option of just adjusting a truss rod rather than having to remove frets and planing down the board. Personal preference.

[Rodger Knox]

Originally Posted by Quickstep192

Dialing in the neck relief was the idea behind it, but perhaps being able to dial in the string height isn't as important with strings that are easier to fret.

That, and the fact that nylon strings need higher action than steel strings makes the relief less important.

[emmsone]

Yep.
now i have to add additional text.

In all seriousness, I had this debate for my own nylon crossover build. I dug around online and found the lightest dual truss rod I could find (it was from allied lutherie). My conclusion is that dialing in an absolutely perfect action by tapering the fretboard is ok in theory. But i'd expect the taper or banana-esque relief of the fretboard may not be so perfect once you've put some frets in. As generally you level the frets, but if your fretboard is banana'd its difficult to get the frets to follow. If you then end up with level frets, what was the point in sanding in relief or a taper. The truss rod gives you this relief back after leveling your frets and in my opinion will make things much easier to get a really good playing action

Long story short, despite the obvious convenience factor, the only thing holding me back was the weight, having found a light one unless someone steals my truss rod (possible due to the apparent heracy of doing such things) or I forget to put it in, i'm installing one in mine.

David

[Rodger Knox]

Originally Posted by emmsone

Yep.
now i have to add additional text.

In all seriousness, I had this debate for my own nylon crossover build. I dug around online and found the lightest dual truss rod I could find (it was from allied lutherie). My conclusion is that dialing in an absolutely perfect action by tapering the fretboard is ok in theory. But i'd expect the taper or banana-esque relief of the fretboard may not be so perfect once you've put some frets in. As generally you level the frets, but if your fretboard is banana'd its difficult to get the frets to follow. If you then end up with level frets, what was the point in sanding in relief or a taper. The truss rod gives you this relief back after leveling your frets and in my opinion will make things much easier to get a really good playing action

Long story short, despite the obvious convenience factor, the only thing holding me back was the weight, having found a light one unless someone steals my truss rod (possible due to the apparent heracy of doing such things) or I forget to put it in, i'm installing one in mine.

David

I would not say it is easy, but it's really not that difficult(its actually easier for me). You do have to take the built-in relief into account when you level the frets, if you have to do that. I usually don't need to level the frets, but I spend a lot of time getting the fretboard exactly right and every fret uniformly seated. I complete the fretboard before gluing it to the neck, and the neck has to be exactly flat. I haven't always done it this way, but have developed my construction methods and sequence over the last 15 years and 20+ guitars.

I might have even recommended using a rod when you asked about it a while back.

[Earl49]

I had a Taylor NS34ce crossover that had a truss rod. It was never really needed (or used). Taylor is set up to build that way already, and it's easier to put it in than to change factory processes to leave it out.

As an aside, I was going to lend it to a friend who hurt his hand and needed something easier to play for a couple of months. When he saw it had a truss rod he immediately said, "Oh, then it can handle steel strings". End of loan.....

[redir]

I guess the thinner neck of the cross over and the fact that the neck is longer (14 fret) might make a case for wanting a truss rod. But it would probably be fine without it.

[Alan Carruth]

One o my students put truss rods in a couple of Classicals he made, and really liked them. OTOH, he made his own rods as well, out of titanium. They were much lighter than usual.

I have had Classical necks move, and have gotten into the habit of putting in a fixed CF rod as insurance. Sometimes you get some wood that has built-in stress or whatever. I've often thought that, with the reduced tension and relatively heavier neck, you could use a lighter rod and still gain the advantages. Normal rods use a 3/16" steel rod, and it might be possible to go to 1/8", with commensurate reduction in the 'static' part of the rod, and reduce the weight by half or more. One of these days I may try it out.

[printer2]

The nylon guitar I made does not have a rod and in winter the action changes. I have put in an aluminum strip in the last couple of necks to hopefully mitigate this problem.

[redir]

I'm still conflicted as to the use of CF bars in classical guitars. Well, any guitar for that matter. I have done it on probably ten guitars so far but then stopped after I read about the engineering and physics involved in a beam in tension and compression that exists along the neutral axis. It sure does seem like it ought to work, but does it really?

I could see it as being useful for reaction wood though as it might break up the tensions involved in the natural material and replace it with something static.

[Rudy4]

I have a Cordoba Fusion, and they consider it a benefit to install a two way rod.

Cordoba has a long history of building classical guitars but they knew the crossover player often requires a lower and more critical action. That's why the truss rod is there.

Listen and learn.

[Brent Hahn]

I have a cheap, ugly Indonesian 12-fret "classical," and the presence of a truss rod in that guitar (which records like a 79-dollar dream) has been a godsend.

[Alan Carruth]

I always put the CF rod in as low down in the neck as possible, with a fill strip on top. This puts the carbon rod in tension, and does seem to limit the amount the neck will pull up.