Graphite vs. Titanium neck reinforcement

[Killed_by_Death]

Hmm, I was just thinking about 100% carbon-fiber necks & what if someone made a neck entirely out of Titanium?

Ti for necks is the flavor of the month.

For years now, and many Many stated that Roasted necks was just a fad, but even I can clearly hear a difference between Roasted & non-roasted.

 

[fhm555]

No engineer but i’m pretty sure the density of graphite has little to do with it’s ability to transmit vibration. Back when fishing rods first started being made with graphite instead of fiberglass, a sales trick employed to demonstrate the increased sensitivity of graphite was to place the tip of a graphite rod against the throat and speak at conversational volume, you could feel the conversation in a graphite rod but not a fiberglass rod. This was an impressive trick, until the modulus race started among graphite blank manufacturers. The goal was a more flexible rod as graphite rods tended to break rather than bend like the fiberglass they were replacing. Conventional wisdom said making the graphite more dense would solve the problem. No matter how dense the graphite became, the throat trick still worked to demonstrate sensitivity. Wall thickness was the thing that made the throat trick so effective, density of the material had no appreciable effect on graphite's ability to transmit vibration.
Based on that i’d say a solid pultruded graphite rod, which is what the few graphite neck stiffeners i’ve actually seen were made of, would probably have a dampening effect on a neck’s ability to transmit certain frequencies. And i could be completely out to lunch with this. I do know my steel stiffened MIM necks take temp extremes better than my graphite stiffened MIA necks.
As for titanium, wouldn’t the more random grain structure versus steel also work against it’s ability to transmit vibration?

 

[Gilmourisgod]

Well, it does say Tone Resonant titanium, which everyone knows is better than Regular Old Garden Variety titanium for Tone Renuberation......and toney stuff. I've used CF bars in two neck through, so far so good. It's virtually impossible to say what, if any, affect it had on tone. I used them to keep my necks stiff, and it worked. Even if if you knew what affect it should have, good luck predicting outcomes in any system made of wood.

 

[deff]

I'm unable to determine if that's what KTS are doing. Here's a blurb about the Ti bars & another photo:

'
Our Graphite is very stiff and inflexible and works best to produce a clean and precise fundamental and related harmonic response for driving analogue pedal trains in detuned, high gain situations.

The KTS Titanium reinforcement is and wider more flexible with a constant “push back” relationship and will flex slightly under pick attack generating a richer tonal range and more complex harmonic response.
'

Vance Custom Guitars (Australia) introduces KTS Titanium Neck Rods | KTS English

View attachment 3619210

Yup. Titanium will flex a bit, but it always returns.

 

[Trabeen]

I’m beginning to really miss the days before TalkBass when a bass was just a cool device for bass players and not something that was to be analyzed down into the quantum realm.

 

[BLDavis]

my wife has titanium in her neck ...

still sounds the same ...!!!

View attachment 3619223

Did you notice any dead spots around the fifth vertebra?
B.

 

[groooooove]

it has to have some effect...

to measure it would be a real nightmare - which is to say, it's stability gaining properties are worth utilizing and not to be concerned with how it changes the vibrations in the instruments.

 

[smtp4me]

Then you’ll have a dead spot at 1.2 kHz. A strange lack of sparkle as the neck soaks up the overtones of every D and G you play.

I'm not a technical expert on the subject matter. I do wonder about dead spots - a stiffening rod is surrounded by the neck wood, therefore wouldn't some of the energy (resonance) it absorbs be transferred right back into the surrounding wood?

 

[deff]

Ti tubes are used in bicycle manufacturing because of their superior ability to dampen vibrations. This all seems like a lot of silliness. Steel is definitely the right choice for truss rods, extra reinforcing rods for the most part seem superfluous to me, but you could certainly design a CF rod to do the trick. I'm not exactly sure how titanium could be treated to orient the grains given their relatively tiny size and weirdness compared to steel to create something that didn't dampen vibrations.

Pull one out, I'll cross section it, prepare a metallographic XS and we can compare it to a more common Ti alloy. We can even run EBSD. Also as the gentleman that is the Civil Engineer said, there isn't enough data on the CF rods they use or the Ti alloy they replaced it with to make kind of informed decision as to efficacy of use.

 

[fretno]

My Vigier has no truss rod at all

 

[micguy]

I’m beginning to really miss the days before TalkBass when a bass was just a cool device for bass players and not something that was to be analyzed down into the quantum realm.

I'm an Acoustical Physicist (schooling), design audio gear for a living, and a bass player. If Talkbass didn't exist, I'd still be analyzing everything about bass guitars down to the last detail. Talkbass gives me a place where it's kinda normal to talk about it. Without Talkbass, I'd be the guy off in a corner, rambling about something that nobody understands.

 

[micguy]

Based on that i’d say a solid pultruded graphite rod, which is what the few graphite neck stiffeners i’ve actually seen were made of, would probably have a dampening effect on a neck’s ability to transmit certain frequencies. And i could be completely out to lunch with this. I do know my steel stiffened MIM necks take temp extremes better than my graphite stiffened MIA necks.
As for titanium, wouldn’t the more random grain structure versus steel also work against it’s ability to transmit vibration?

As far as damping goes (what you're talking about without maybe knowing the technical term) graphite has more damping than titanium, but with either one, it's not about the damping in the reinforcement rod itself, you have to consider the entire system. With all that wood surrounding the reinforcement rods, the system is dominated by the damping in the wood - as the neck flexes, the outer parts (which are all wood) move the most, and hence the damping in those parts dominates. Think of the system as analogous to a bass drum in air (low damping) that you lower into water - the thing won't ring when all that water is coupled to the drum head. If you want to make a neck more resonant, roasting the wood (which does reduce the damping by turning some of the resin into hard crystalline stuff) is what you would do to have a significant effect. Even then, it's still wood - it rings more, but not like if the thing were made of metal. I have a few roasted necks - the additional stiffness moves the dead spots up the neck a couple frets, and as a result makes them less noticeable, even though the reduced damping is working against you somewhat.

 

[Allegrus]

I don't get the goal here. What is the point of these reinforcing rods? Someone is selling the market on the idea that stiffer necks are correlated to better tone and long term stability. I don't get that; we have lots of anecdotal evidence this is not true.

 

[Blaze Barlow]

my wife has titanium in her neck ...

still sounds the same ...!!!

View attachment 3619223

thats funny and I like it..made me laugh..I have titanium in my leg and generally sound the same too..thanks.

 

[bucephylus]

It is rather darkly amusing to read so many attempts at technical analysis by non-engineering bass players.

I actually have some background in the applied mechanics of layered structures, like a bass neck; and I have to honestly say that I have no idea what the performance difference between graphite and titanium reinforcing bars would be.

Density doesn’t have much to do with the problem, except for weight and balance. I too have had one of those Warmoth necks with the steel reinforcing rods, which I’ve owned since 1988. It has spent the past 28 years sitting in my closet, because...well I just don’t like it. Probably should sell it. Heavy and unresponsive would be adjectives I’d use; but, wouldn’t sound good in a classified ad.

I do have basses with either graphite reinforcing bars or whole necks. Good stuff.

Graphite vs Titanium as reinforcing bars? No idea, and I doubt the comparison is theoretically predictable. The titanium is certainly lighter than steel. So solves that issue. How the two materials affect playing characteristics. I suspect you would need to talk to some of the luthiers, such as Roger Sadowsky or Mike Tobias to see if they have actually done any comparative studies between otherwise similar instruments.

It’s a good Q. I’m not aware of any solid relevant data, and not otherwise predictable, IMO.

 

[bucephylus]

I don't get the goal here. What is the point of these reinforcing rods? Someone is selling the market on the idea that stiffer necks are correlated to better tone and long term stability. I don't get that; we have lots of anecdotal evidence this is not true.

Such reinforcing rods are generally used to make the necks more uniform and reduce the occurrence of significant dead spots. I think Roger Sadowsky talks about it in one of his YouTube videos. They have been in use by major companies, such as Fender, for about two decades.

 

[arbiterusa]

I used to race bicycles. Have taken a few Ti frame bikes out. I wouldn't use it for neck reinforcement. It's not stiff. Oh, you can't break it, it's super strong and so light you can't believe it's a metal, but it's VERY flexy. So much so that in spite of the staggering weight advantage, I wouldn't want a Ti bike frame.

I also wouldn't use it in an instrument neck.

You won't permanently bend or deform titanium rods though.

I have a post-crash Ti handlebar that disagrees with this statement. You absolutely can permanently bend the stuff.

 

[fhm555]

I don't get the goal here. What is the point of these reinforcing rods? Someone is selling the market on the idea that stiffer necks are correlated to better tone and long term stability. I don't get that; we have lots of anecdotal evidence this is not true.

AFAIK my first bass had nothing in the neck, including a truss rod. These days it’s twisted to beat the band. I can’t begin to speak about how rods might shape tone but my experience has consistently been the necks i have with steel in them are hands down the most stable necks i have. I’ve got graphite stiffened necks, steel stiffened necks and whatever Ibanez would use in a $400 bass. Of those, the necks with steel rods are the most stable when exposed to temp extremes.

 

[ctmullins]

For completeness' sake, I have a few three-piece laminated rock maple necks that I built that have no auxiliary reinforcement (they have an adjustable truss rod, but the purpose of the truss rod is not for reinforcement or stiffening), and they are incredibly stiff and stable. They also have a fairly beefy profile, which clearly helps.

 

[micguy]

I don't get the goal here. What is the point of these reinforcing rods? Someone is selling the market on the idea that stiffer necks are correlated to better tone and long term stability. I don't get that; we have lots of anecdotal evidence this is not true.

My anecdotal evidence strongly conflicts with yours - I have a bunch of roasted (which helps stability) necks with graphite reinforcements (which also helps stability). The only time I ever tweak a truss rod (I don't really have to, but when you have the tools to measure neck relief within a thousandth of an inch), you end up doing that...is when I change to a set of strings with significantly different tension. That changes neck relief a bit, so I compensate, but if I didn't have the tools to do that measurement, I'd probably be happy never touching my truss rods. On a regular maple, non- reinforced neck, I'd be chasing the truss rod adjustment when the weather changes - at least a couple times a year. I also have had standard necks that warped to where they were not longer playable - that doesn't happen with well made reinforced necks.