What is the point of having a slight bow in your truss rod?

[Tupac]

What's the point of this? I've heard that for slapping, it's best to just keep it perfectly flat or ever so slightly bowed. Would it be bad to make it perfectly straight?

[Basshoofd]

The bow is to let the strings move freely without hitting the frets. If you trussrod isn't adjusted properly you will get fretbuzz quicker. Too much bow will give buzz at the higher frets, too straight will give you buzz at the lower frets. So, set your trussrod so you buzz equally over the entire neck, then set your preferred string height.

The lower you have your action, the more accurate you have to set your trussrod.

[FunkMetalBass]

On the first page of the Gary Willis' setup guide, there's an animated image that explains it well.
Adjusting The Neck

The whole thing is actually a great introduction to setting up a bass. Highly recommended.

[Ric5]

I like the neck flat or almost flat.

This helps with getting a good low B string.

[202dy]

Originally Posted by FunkMetalBass

On the first page of the Gary Willis' setup guide, there's an animated image that explains it well.
Adjusting The Neck

The whole thing is actually a great introduction to setting up a bass. Highly recommended.

The link to the Gary Willis set up guide was removed from the sticky at the top of the page. The reasoning is the information contained therein is questionable on the best of days. Some of it is just wrong. Luthier's and techs-the folks that make their livings doing set up and repair work-do not perform the work as GW suggests because it is neither accurate nor efficient.

Not recommended.

[Nev375]

Because when strings vibrate they do so with a sort of an elongated football shape like a jump rope. You can actually achieve a lower overall action without fret buzz with a slight curve rather than perfectly straight.

[KingRazor]

From Jerzy Drozd's setup guide.

[Basshoofd]

Originally Posted by 202dy

The link to the Gary Willis set up guide was removed from the sticky at the top of the page. The reasoning is the information contained therein is questionable on the best of days. Some of it is just wrong. Luthier's and techs-the folks that make their livings doing set up and repair work-do not perform the work as GW suggests because it is neither accurate nor efficient.

Not recommended.

Out of curiosity, what did he suggest that was questionable?

[Coolhandjjl]

Originally Posted by Nev375

Because when strings vibrate they do so with a sort of an elongated football shape like a jump rope. You can actually achieve a lower overall action without fret buzz with a slight curve rather than perfectly straight.

By doing this, I am now able to get super low action w/o fret buzz. Having a perfectly laser straight neck is false pride.

[FretlessMainly]

Well, not necessarily. On a Rick, for example, getting the neck dead flat has nothing to do with getting low action for me. I like the neck flat because the instrument is designed to function better from a wood vibrational and sustain perspective this way. I set my Rick necks dead flat and then jack up the action to my liking.

As to the OP's question, a bow in your truss rod is part of how the truss rod functions. You can have a bow in your truss rod and have a dead flat neck. Having a bow in your neck allows for the free string vibration described above. On my Fenders, I like a bit of up-bow.

[202dy]

Originally Posted by Basshoofd

Out of curiosity, what did he suggest that was questionable?

His methods are questionable. He advocates trial and error without establishing a base line. It is poke and hope. Why would anyone instruct a novice to do it in a way that is sure to frustrate? That is akin to putting a penny in a round room and instructing the student to find it in the corner.

Unless Mr. Willis is able to suspend the laws of physics in the area of his guitar his "pc board spacer to decrease tension" idea is just plain wrong.

The problem here is that Gary is an incredible player. Therefore, people draw an illogical conclusion that he is a great tech. Advertising companies know this all too well. That is how they sell tennis shoes, makeup, and life insurance.

This is all off topic. If you would like to discuss this further, PM me or start a new thread.

Respectfully submitted.

[tstone]

Originally Posted by FretlessMainly

I like the neck flat because the instrument is designed to function better from a wood vibrational and sustain perspective this way.

Wait a minute, let me put on my waders.

[georgestrings]

Originally Posted by tstone

Wait a minute, let me put on my waders.

Yeah, I thought it was a load of BS, also...


- georgestrings

[Solarmist]

One needs some neck relief to account for string oscillation.

[FretlessMainly]

Originally Posted by tstone

Wait a minute, let me put on my waders.

Charming.

Perhaps designed isn't the appropriate word, but in my experience with Rickenbackers, which dates back to 1980, small changes in neck angle at or very near the "dead flat" point can make a very large difference in how the instrument speaks.

Case in point, my 4003FL (bought used) arrived to me with a touch of back bow and the harmonics were stilted and tight. Less than a quarter turn of the rods brought the neck back to near dead flat and the harmonics opened up like you read about. Ringing true and clear and long. Just for the hell of it, I added a touch more relief and the harmonics became a bit more muddy; not as bad as with back-bow, but not quite right. So, I brought the neck back to how I had set it.

I also found that these small truss rod tweakes had marked effect on the positioning and severity of a dead spot; 9th-10th "fret" on the D string. A common problem on some Ricks.

So call bunk if you like, but I have the physical and aural evidence I need to indicate that having the neck just about dead flat is a sweet spot that I would assume had something to do with how the instrument was designed. Further, I recklessly assumed that the concomitant improvement in sustain must have something to do with the configuration of the wood of the neck-thru instrument and how the vibrations from the strings are transmitted through said wood.

[Ric5]

I got used to flat necks playing Rickenbackers ... and now I like them ...

[walterw]

Originally Posted by KingRazor

From Jerzy Drozd's setup guide.

i'm calling BS on this example!

it looks good on the open string, but what happens when you fret in the middle of the neck?

just assume that the string vibration will create a similar pointed ellipse shape starting from wherever you fret it;

with the flatter neck, that ellipse still pretty much clears the board.

with the bowed neck, the ellipse will get wider right where the end of the neck curves up!

the higher frets will interfere with the string, causing buzz.

in the real world, that's exactly what happens; too much bow is followed by dropping the saddles to get "lower action", which is followed by buzzing on all the higher frets.

[walterw]

i haven't looked over the set up guide, but if this is an example, we need to stop recommending it, and maybe even de-sticky it.

[96tbird]

You know, there is some good reasoning there Walter, besides reinforced necks were developed to keep geetar necks flat when steel strings were introduced. From that the adjustable rod evolved.

[walterw]

neck reinforcement's got nuttin' ta do wid it!

the physics hold true whether it's a vintage fender or a steinberger.

(although you're right of course, the truss rod came about soon after the adoption of steel guitar, mandolin, and banjo strings in the '20s.)