Explain Why CF Guitars Don't Need a Truss Rod

[denny1948golf]

Originally Posted by mchalebk

Wood guitars need truss rods because they change over time and with varying environmental conditions. CF guitars don't need them because they don't change.

A lot of people will argue that they need a truss rod to set their action for their style of playing. However, truss rods aren't really supposed to be used to adjust action, only relief. Once relief is set properly, the nut and saddle are all that need to be adjusted to get the desired action.

I think the bottom line is that any guitar can benefit from having a truss rod. However, most guitarists are fine with an average relief setting and won't ever need to change it, so they can get away without a truss rod in a CF guitar due to the unique characteristics of composite construction.

Well put! Especially since you included "bottom line is that any guitar can benefit from having a truss rod" Sounds like I'd be fine buying a CF guitar without a truss rod, but I'd still prefer to have the truss rod. That said, I'd go for the most comfortable neck profile over a neck I didn't like that had a truss rod.

[Cass Sumrall]

Originally Posted by denny1948golf

Well put! Especially since you included "bottom line is that any guitar can benefit from having a truss rod" Sounds like I'd be fine buying a CF guitar without a truss rod, but I'd still prefer to have the truss rod. That said, I'd go for the most comfortable neck profile over a neck I didn't like that had a truss rod.

Denny,

I agree with the above but would point out that none of the pre-war guitars that many of us revere had adjustable truss rods. As you know, I am a tinkerer & like the action on my guitars "perfect" but I don't have any problem with my vintage guitars that are not adjustable because they are stable & had the correct amount of relief from the start.

The same is true of most CA guitars in my experience. I have had a bunch of them & only got one with a bad neck angle that had to be replaced by CA. The rest have had both good neck angle & relief & have remained stable in the years I have had them. They are just like my vintage guitars in that regard.

I still have several CA's, all with good necks, if you are looking for one - both the GXRT & The Legacy.

If you like the neck on a Taylor, you will like the neck on CA's - very similar.

Cass Sumrall

[Mr. Ed]

Cass, I agree with your reasoning.

I have a Rainsong OM-1000 with the N1 neck - no truss rod & is thin and very easy to play. Different weight of strings has made no difference in the relief. It has been rock solid.

[Jim K]

A CF guitar will not need a truss rod, IF the neck left the factory with appropriate relief.

My first carbon guitar was a CA GX in 2008. The neck of the GX was overly bowed to the extent that saddle shaving could not achieve reasonable relief. That GX was replaced under warranty a few weeks before CA closed its doors. The replacement GX was ok, but may have had a neck that was actually too straight.

I eventually traded the warranty replacement GX in on a RainSong CO-WS1000N2 (with a truss rod), and been very pleased. My local luthier/repair tech, adjusted both truss rod and the saddle and set up the CO-WS1000N2 to excellent, playable action.

[Doubleneck]

I wonder if the truss rod thing started in carbon guitars mainly to give a comfort level to wood guitar players that are used to seeing them and adjusting them. I don't mind having one in my Rainsong OM N2 and have used it. But my CA is dead on so really do no miss it at all there.
Steve

[mchalebk]

Originally Posted by Jim K

The neck of the GX was overly bowed to the extent that saddle shaving could not achieve reasonable relief.

Jim, I believe you probably understand about relief, but thought I’d comment on this because there are so many misconceptions about what truss rods actually are used for.

You cannot adjust relief at the saddle. Relief is purely adjusted with the truss rod. When measuring relief, I believe one of the more common ways is to place a capo on the 1st fret (which takes the nut out of the equation) and fret the string at the 12th or 14th fret (where the neck joins the body; this takes the saddle out of the equation). Relief can then be measured at the halfway point (around the 7th or 8th fret).

If a guitar doesn’t have a truss rod and has too much relief, you can try to compensate by lowering the saddle. However, nothing you do at the saddle will actually affect the relief, only the action.

As long as a CF guitar has the appropriate amount of relief, it shouldn’t need a truss rod for the vast majority of guitarists because the amount of relief will not change over time or due to environmental conditions. Some guitarists prefer more or less than the standard amount of relief and will usually require a truss rod.

[Jim K]

Brian,

I agree with your comments. My prior post was not worded accurately. What I meant to say is that the neck of my original GX had too much relief, and was bowed upwards to the point that saddle shaving could not achieve reasonable "action". The saddle was shaved down to the point of almost no saddle left, no string break angle over the saddle, and the action was still high. This was not my assessment, but was the assessment of Elderly Instruments in Lansing, MI.

If the GX had had a truss rod, the neck relief (i.e. neck bow) may have been capable of being adjusted to a level that, combined with saddle modifications, might have achieved reasonable action. But with no truss rod, when a neck having relief outside of tolerances was shipped from the factory, the old CA had no choice but to replace the "entire guitar".

You correctly reference that achieving appropriate action involves both the neck relief, the height of the saddle, . . . and also the depth of the nut slots.

If a CA guitar was shipped, like your Legacy, with suitable neck relief, minor saddle adjustments, if any were needed, could result in desired action which would not change. If neck relief was outside of tolerance, then there were problems.

The new CA/Peavey can succeed with the no truss rod design, but their factory quality assurance checks will have to adhere to much tighter tolerances than the old CA operated to at times.

Regards,
Jim K

[blue]

The raw materials for CF are incredibly expensive. It would be possible to build a neck that was straight and wouldn't bow regardless of string guage, but it would be more expensive because at some point engineering can only go so far and you need more material in there.

I wouldn't buy one without a truss rod. In fact, I'm kind of waiting for CF guitars to advance to the point were there is "something else" other than truss rod. Something that evolves with the material as opposed to coming over from wood guitar design. Where's Ken Parker when you need him?

[RP]

Originally Posted by blue

I wouldn't buy one without a truss rod. In fact, I'm kind of waiting for CF guitars to advance to the point were there is "something else" other than truss rod. Something that evolves with the material as opposed to coming over from wood guitar design. Where's Ken Parker when you need him?

Maybe they could go the PRS route and use a non-adjustable carbon fiber truss rod. That would be CF borrowing from wood which borrowed from CF ad infinitum....

[blue]

Originally Posted by jrporter

Maybe they could go the PRS route and use a non-adjustable carbon fiber truss rod. That would be CF borrowing from wood which borrowed from CF ad infinitum....

Hey. Whatever works. But that's really just using a different material to replace first ebony, then metal embedded in the neck for strength. I hope you do get my point though. It's a different material. They are already engineered differently with things like one piece neck/bodies etc. I'm just waiting for them to mature a little more.

[dkoloff]

Originally Posted by Jim K

A CF guitar will not need a truss rod, IF the neck left the factory with appropriate relief.

My first carbon guitar was a CA GX in 2008. The neck of the GX was overly bowed to the extent that saddle shaving could not achieve reasonable relief. That GX was replaced under warranty a few weeks before CA closed its doors. The replacement GX was ok, but may have had a neck that was actually too straight.

I eventually traded the warranty replacement GX in on a RainSong CO-WS1000N2 (with a truss rod), and been very pleased. My local luthier/repair tech, adjusted both truss rod and the saddle and set up the CO-WS1000N2 to excellent, playable action.

For those who really are dialed in to a feel the truss rod does make the difference but on a CF particularly if the neck angle is correct you should not miss the truss rod.

[Longshot888]

Personaly I would not buy a guitar with out one, I bought my First CF off ebay a used 2011 S-OM1000N2 rainsong, I recived the guitar and was very unhappy with the set up, the saddle was about a 1/16 to high, and the truss rod had not been used at all.
After my guy worked it over , it is now the best playing guitar i have ever played. this would not have been possible with out one.

[mchalebk]

Originally Posted by Longshot888

Personaly I would not buy a guitar with out one, I bought my First CF off ebay a used 2011 S-OM1000N2 rainsong, I recived the guitar and was very unhappy with the set up, the saddle was about a 1/16 to high, and the truss rod had not been used at all.
After my guy worked it over , it is now the best playing guitar i have ever played. this would not have been possible with out one.

While the truss rod may not have been used, it's worth pointing out that it may have been misadjusted. While it may not have been possible to make the adjustments necessary if the guitar didn't have a truss rod, it's also possible the guitar may not have needed the same adjustments if it had been built without one.

One of the problems with having a truss rod is that it can be out of adjustment. If a CF guitar doesn't have a truss rod and is constructed properly, it won't need a truss rod for the vast majority of players.

[Doubleneck]

I would suspect that your adjustment came from lowering the saddle and not from the truss rod. Not unless the neck was not right. Like sad before the truss rod sets relief not string height. I had a CA Legacy that had perfect relief and I just lowered the saddle.

[leeasam]

relief is also a personal feel thing too. One reason I will not buy another guitar with out the ability to adjust it. If my 07 CA GX performer had one I may still own it. I got tire of the high action and such and when I got the saddle down to even what is considered STANDARD atthe 12th fret the string would rattle way to easy in the lower fret area. Well that means the neck is too striaght for your style. Well without the truss rod you can not adjust it. I tried medium string to be able to run lower action( not as much oscillation vs lights) but it pulled quite a bit of relief to the neck and then it was too much. Contrary to the line of ----- that it would not change the relief by changing string gauge. My Taylor is way easier and less painful to play with mediums on it than my CA GX was with lights.

SO what is the purpose of a truss rod. TWO FOLD! One --to counter act the pull of the strings on the neck-- wood needs this-- for it not too you would have to have a neck like the big end of a base ball bat-- A CF built right does not-- TWO- to adjust the correct amount of relief for personal feel. There is a standard here just like action but players all differ. Truss rod allows for this CF guitars with out do not.