Ukulele Truss Rods

GX9901 said:

I had a Pono tenor with the adjustable truss rod. I actually was able to lower the action a tiny bit into an acceptable range using that adjustment. I don't think the reason for having the truss rod was for action adjustment though.

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truss rods are not generally supposed to be use to adjust action. they are used as somewhat of a counterbalance from the one-sided stress the string can put on the neck. when there is too much tension, stress from the strings can cause the neck to bow, thus raising the action in the higher frets. so, in a way, action can be adjusted using a truss rod, but only if it is in the process of straightening the neck.

you can see if your neck is bowed simply by looking down the length of the neck from the bridge, or you can do what i do... pick a string, either end. fret the string at the first fret with one hand. on the other hand, fret the string where the neck meets the body. if the string is just barely touching all the frets all the way down, then the neck is pretty straight. if the string is raised up off the frets, you have a bow. a little bow is not bad IMO. but its pretty obvious if youve got too much. if the strings are all touching the frets before you fully fret the string at the body, then you may have a backward bow... this is not going to be common in most ukes since they dont come with truss rods, but if you do, or if you check your guitar and its doing this, then you may want to back off of the tension on the truss a bit.

i have a question...

is it possible to install a truss rod or reinforcement rod on an ukulele thats already built?

i have access to the said ukulele that has a bowed neck. and the knowledge of knowing that it exists in such a way, even though i tried a few tricks of my own to straighten it, just irks me.

so i was thinking of taking the ukulele, dredging out a channel in the back of the neck, inserting a length of carbon fiber cut off of a fishing rod, expoxy in, seal up, and voila!

chuck... kekani... what you guys think? am i insane? if you say i am... ill do it!!! remember im the guy that converted a 6 string ukulele to a 4 string and used linoleum floor tiling as a pick guard. but if it works... :shaka:

You almost touched on "fret board relief", where the slightest amount of bow is desirable to compensate for the arc of the vibrating string. Ukuleles normally do a bit of this by themselves.

NukeDOC said:

i have a question...
chuck... kekani... what you guys think? am i insane? if you say i am... ill do it!!! remember im the guy that converted a 6 string ukulele to a 4 string and used linoleum floor tiling as a pick guard. but if it works... :shaka:

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Yes, of course you're insane, but we can talk about that later.
If that we my uke and I really wanted to put the effort in it, I would first remove the neck and then the fret board. I'd do my best to straighten the neck by clamping it to a caul, using heat/steam, reshaping whatever it took to straighten it depending upon how bad it is. A channel could then be made into the top of the fretboard, a reinforcement rod installed, fret board glued back on and neck reassembled. Doing it this way you could also check the set of the neck and adjust if necessary. There are probably other ways to do this, this is how I would handle it.

Moore Bettah Ukuleles said:

You almost touched on "fret board relief", where the slightest amount of bow is desirable to compensate for the arc of the vibrating string. Ukuleles normally do a bit of this by themselves.

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i was thinking about that, but i just couldnt remember what to call it. fret board relief. thats it. thanks chuck!

Moore Bettah Ukuleles said:

Yes, of course you're insane, but we can talk about that later.
If that we my uke and I really wanted to put the effort in it, I would first remove the neck and then the fret board. I'd do my best to straighten the neck by clamping it to a caul, using heat/steam, reshaping whatever it took to straighten it depending upon how bad it is. A channel could then be made into the top of the fretboard, a reinforcement rod installed, fret board glued back on and neck reassembled. Doing it this way you could also check the set of the neck and adjust if necessary. There are probably other ways to do this, this is how I would handle it.

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if i were you... i, too, would handle it in such a manner. hahaha. when it comes to electric guitars, ill take that baby apart and put it back together like reassembling a 1911 inside a black plastic bag. but acoustic instruments... i'm a-feared. ill only go so far and chock it up as experience, or mark it down as a mistake that i should NEVER repeat. but im also stubborn. i work with the tools at hand... screwdrivers, rotary, files, pliers, soldering iron, and sometimes unorthodox tools that were not meant for the job but worked. disassembling the neck and fretboard... if i got that far... then next thing im doing is building my own ukulele. i dont quite wanna do that yet. i do, i just cant afford it.

so im thinking... your opinion is that what im planning is going to end up as one of those "mistakes". please dont answer that. if you say no, im gonna go ahead and do it. if you say yes, im gonna do it just to say "i told you so" knowing full well that you're probably going to end up being the one to say it to me. hahaha.

youre a gentleman and a scholar, chuck. thank you for your ideas, concern, advice, and motivation.

Honestly, what I was going to suggest originally is to simply throw it away. That's what I'd do.
Why don't you just take care of the bow in the neck and not worry about reinforcing it? The neck has probably moved all it's going to by now anyway.
You want to do it the real easy way? Simply pull the frets, sand the fret board flat, (or put some relief in it if you wish) recut the fret slots and press the frets back in. Level and dress the frets and your done. It's kind of cheating but done all the time on cheaper instruments. Makes the fret board a bit thinner in the middle but at least it becomes playable again.

Really?

hoosierhiver said:

I think Baritones should have a truss rod,I've seen alot of bad baritones because they lack a truss rod and the neck pulls forward when they are under tension making the action too high.

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Baritone strings are like classical guitar strings. Most classical guitars don't have a truss rod so why would a baritone need one.

Steel strung instruments need a truss rod. As mentioned a truss rod allows to adjust the tension to set the neck.more or less bow.
Thicker strings have a greater tension so pull more on the neck, so they need more tension onmtne rruss rod to keep the neck straight. Lighter strings need less tension. Weather, heat, cold, humidity, all affect things too.

Mickeyj4j said:

Baritone strings are like classical guitar strings. Most classical guitars don't have a truss rod so why would a baritone need one.

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More recently built classical guitars frequently do have truss rods, and it doesn't seem uncommon that older guitars without truss or reinforcement rods have neck issues.

The one baritone I had (a Pono) had an adjustable truss rod. It was a plus, I felt.

I did a bunch of research on this when I was buying a banjo. Almost all 5-string banjos produced now have a truss rod except the Deering Goodtime series. Deering's explanation for why they didn't need a truss rod is as follows:

Truss rods are used to correct for changes in neck profile over time. Changes in neck profile over time occur because wood changes size with humidity. This happens because most instrument necks have two pieces of wood glued together (neck and fretboard) and they don't change size at the same rate - when one expands or contracts more than the other, the neck will tend to curve. Goodtime banjos don't have a separate fretboard (the neck and fretboard are all one piece), so they are less likely to experience neck profile changes due to expansion or contraction of the wood.

The reason that most ukes don't need a truss rod is because the neck is short enough that even if you get some neck profile changes they are pretty minor. That said, I've seen sopranos develop buzzes over time where I live (high desert), and the local music store doesn't do much with baritone ukes because their longer necks don't last in our climate. That's why I really like my Pono Baritone. I've already used the truss rod to correct some buzzing and I won't buy a baritone without one.

Mmmhhh, I think, Pono truss rods are adjustable:

http://blog.anthillmusic.com/the-repair-journal/found-the-only-ukulele-with-an-adjustable-truss-rod/

The truss rod is a reassuring thing. Perhaps not necessary, but reassuring. About 8 years ago we bought classical guitars for a school guitar program (high school), entry level Yamaha models. There were many reasons for going classical--but many of the necks warped after the first two years in a non-humidity controlled music suite (which was supposed to be humidity controlled) and while they killed those courses after I left (that is a discussion for another time) those instruments still sit in their cases with many having warped necks.

I decided that any guitar I ever buy again will have a truss rod.

Ukuleles have nowhere near the tension of even a classical guitar; but I do worry sometimes about my Opio and if it will stand the test of time without the neck warping. I won't have to worry about that, ever, with the Pono.

Chunk, though you make the ultimate ukuleles (which the likes of me shall neither play or own) but I respectfully beg to differ because I know that Pono Tenor and Godin ukuleles have true truss rods...

-- Gary