Truss Rod Adjustment - Balance Question

[SnarlyHovel]

Hi Everyone!

Let me start by saying that I know this is a topic that has been covered both here and in the 'Support' section of the Alembic website, but I have been unable to resolve a neck relief issue and am hoping someone out there can help.

I recently changed string gauges on my Essence, which increased the tension and led me to adjust the neck (I went from 35-55-75-95 Ken Smiths to 45-65-80-100 EB Flats.) The guidance here is to always adjust both rods the same amount, to avoid twisting the neck. I know from other forum posts that this isn't a hard and fast rule, but I seem to be getting VERY different reliefs on the E string vs the G. Adjusting both rods in sync, I can get my E string into a 'normal' relief, but when I depress the 1st & 24th fret of the G, the string is touching the frets across the middle.

I know that was a long setup (pun intended), but is there a way for me to tell if the truss rods were already unevenly adjusted? If not, would adjusting the rods independently help me accomplish the relief I want on both ends? How far apart can the truss rods be adjusted before experiencing twist?

Thanks in advance for all your input!
Ryan

[lbpesq]

Hi Ryan, and welcome to the club!   

I don't know where you read that the two rods have to be adjusted the same.  The link you provide to the Alembic adjustment page doesn't say that.   Rather, it states:  "These are independent from one another; each adjusts one side only."   You should go ahead and adjust each side individually to taste.  That's what they're there for.

Bill, the guitar one

[rv_bass]

Ryan, have you tried loosening both rods up all the way to get to a neutral starting point, then tightening both the same amount?  Others more knowledgeable can speak about tightening one more than the other. Bridge adjustments in combination with truss rod adjustments can help too (i.e., Joey’s post in the FAQ section). Keep working on it, you will get it.

…Looks like Bill was a quicker typer than me! 

[SnarlyHovel]

I don't know where you read that the two rods have to be adjusted the same.  The link you provide to the Alembic adjustment page doesn't say that.   Rather, it states:  "These are independent from one another; each adjusts one side only."   You should go ahead and adjust each side individually to taste.  That's what they're there for.
Bill, the guitar oone

Thanks Bill, you're right - I guess I read that in the forum post that I linked to instead

[StephenR]

I believe the thing you do not want to do is really crank one rod and really loosen the other. They were designed to be independently adjustable but you still have to exercise good judgement when doing so. Once you get the hang of making adjustments to your Alembic you will realize how superior their truss-rod system is. Even though I would welcome individually adjustable bridge saddles like the custom ones made for Phil Lesh, for the most part they aren't necessary since each bridge assembly is contoured to match the radius of the fingerboard. The Alembics I own are are my easiest instruments to set up.

The other important thing is that after a truss-rod tweak it is best to wait a day before adjusting further. The necks are stiff and it can take a while before the adjustments settle in. As long as you move slowly and in increments it is very difficult to make a mess of things. Good Luck!

[jazzyvee]

I'm glad you posted this as i also was under the impression that the two rods should be about the same. So far this strategy has worked fine except my series II 5 string which could do with a bit more relief on the G-string so I will have a go at doing that soon.

[bigredbass]

I've come to change my thinking about this (and my adjustment post is under re-consideration by me).

My basses always felt the same on both nuts.  They always adjusted using both as if there were only one with relief the same on the high and low sides, adjusting both nuts to the same felt tightness.

However, I always wondered what I'd do IF I ran across a situation just like SnarlyHovel reports.  So, I'd advise adjusting the tension on the bass side as a separate operation from the high side, adjusting both to the same end result.  In my case, with the feeler gages, I'd adjust until I got 12/1000 under the E or B, and the same on the G/C side, and my advice would be to do this on any Alembic.

Since there's no room at the truss rod nuts to use any kind of torque wrench to set or measure tension, we'll do it 'coming from the other direction' by setting to a set relief (that 12/1000ths as a starting point for those it doesn't quite suit, or a finish for those it does) on each side of the fingerboard.

We'd follow the same process for adjustment . . .

Truss rod (except do each separately to the same end result)
Action
Intonation

with side-trips, if necessary, for . . .

pickup height adjustment
nut height (clearance over the first fret)

And as always:  This is for working basses with minor relief issues, fret wear, etc.  For basses with real problems, as always, find a pro, experienced guitar tech where you live and have things professionally taken care of.

[KR]

Hi Everyone!

Let me start by saying that I know this is a topic that has been covered both here and in the 'Support' section of the Alembic website, but I have been unable to resolve a neck relief issue and am hoping someone out there can help.

I recently changed string gauges on my Essence, which increased the tension and led me to adjust the neck (I went from 35-55-75-95 Ken Smiths to 45-65-80-100 EB Flats.) The guidance here is to always adjust both rods the same amount, to avoid twisting the neck. I know from other forum posts that this isn't a hard and fast rule, but I seem to be getting VERY different reliefs on the E string vs the G. Adjusting both rods in sync, I can get my E string into a 'normal' relief, but when I depress the 1st & 24th fret of the G, the string is touching the frets across the middle.

I know that was a long setup (pun intended), but is there a way for me to tell if the truss rods were already unevenly adjusted? If not, would adjusting the rods independently help me accomplish the relief I want on both ends? How far apart can the truss rods be adjusted before experiencing twist?

Thanks in advance for all your input!
Ryan

Hi Ryan, My Series 1 has a looser truss nut on the G side. It just got dry here in So Cal and I had to tighten my E side about a full 1/4 turn or more, and my G side only needed just a tiny bit of tightening. I initially tried to set both rods the same, but the G side doesn't need as much help as the E side.

[keith_h]

When starting from scratch I loosen the truss rod nuts fully. I then snug them up to the end of the neck and start adjusting them turning both the same amount. Once I have set the low side of the neck relief to where I want it I will check the high side relief. If it is not where I want it I will adjust the high side rod until the G string has the relief I am looking for. I have never had a case where the high side adjustment was more than tweak one way or the other of the truss rod nut.

To expand with my opinion on Joey's post a bit. We don't know that each truss rod is at the exact same starting point as there are a number of variables that can introduce variations. The necks are hand carved so there will be some natural variance in thickness, width, truss rod locations, etc. When the nuts are set on the truss rod as Joey says no torque wrenches are used so being snug does not mean the rods will have an identical starting tension. Then there is how the wood has or has not absorbed humidity at the time of adjustment. Fret seating and wear will affect relief as well. I'm sure there are other variations involved with how a neck reacts to adjustments. In the end adjusting the both rods the same amount for the initial setting of relief should prevent the neck from developing any bad twists. The fine tuning of each side of the neck using the individual rods should never be enough to cause a neck to twist and is more likely to have the effect of keeping the neck straight and true. 

[SnarlyHovel]

Thanks to everyone for your input!

I will say that this has made me a bit more comfortable with my current adjustment work, though I am still surprised that the tension is so differently balanced compared to my previous setup, requiring such different adjustment of each truss rod.

¯\_(ツ)_/¯

[SnarlyHovel]

UPDATE:

So, I could not balance the relief on either end until I completely loosened both nuts and allowed the neck some time to bow (homonymous pun intended) to the string tension. Once I felt it had settled, I began to tighten both sides, though tending toward the low E. I am happy to report that I now have the relief I wanted on both E and G with a LOT less effort than attempting to adjust from the existing tension.

Hopefully this helps anyone else looking to resolve similar problems. Thanks again for all your input!

Ryan

[keith_h]

Good to hear you got things set the way you like. It is not unheard of that someone needs to loosen the truss rods fully and let the instrument rest with tension before doing a new setup. Thanks for the update. Resolution updates are always helpful for folks searching the site.

[hieronymous]

Glad you got it sorted out! And if I ever need another alter-ego, I'm going with homonymous!

[SnarlyHovel]

Glad you got it sorted out! And if I ever need another alter-ego, I'm going with homonymous!

What you did there?







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