Adjust Neck Relief With Or Without String Tension?

[calvanesebob]

Most examples just show the truss rod being adjusted with string tension, but I have seen a few that recommend loosening the strings.

Also very few specify tuning to pitch after the adjustment, and I even saw a few where the person measured the relief right after the adjustment without even re tuning the guitar.

I would think that the full tension of the strings would cause more stress on the adjustment mechanism and adding more of a chance damage on a "hard to turn" truss rod. Especially when tightening.

Would like to know other thoughts on this.

[Talldad]

Luthiers build fretboards to be perfectly flat. The truss rod is there to counteract the pull of the strings that work to deform the fretboard. If you loosen the truss rod, ideally your guitar will revert to flat.

The relief you are aiming for is that which exists under tension.

You can measure relief when the system is fully tuned up; adjust the truss rod, retune, measure.

[mirwa]

Adjusting the truss rod under tension is perfectly fine, I do however proceed with caution on 12 strings and bass guitars, if i feel undue resistance I will back the strings of on these.

Steve

[Alan Carruth]

Talldad wrote:
"Luthiers build fretboards to be perfectly flat."

Not always. I try to build in the proper relief when there is no tension on the strings or the rod. I then measure how much the neck pulls up under string tension, and adjust the rod to pull it back by that amount. In theory this makes the 'up' load of the strings and the 'down' load of the rod equal, so that there's no net bending stress on the neck; only compression. It's the bending stress, and resulting shear in the wood, that causes the neck to 'creep' upward over time, or, at least, that's how I understand it.

[jonfields45]

Many factory guitars with one way truss rods are built with relief under no tension. I think this was one of Fender's learning events well after they switched to rosewood fingerboards (when returning to slab after thin laminate rosewood). From my own experience it might be that Taylors and Indonesian Squiers are built with no tension forward relief.

[bnjp]

Originally Posted by mirwa

Adjusting the truss rod under tension is perfectly fine, I do however proceed with caution on 12 strings and bass guitars, if i feel undue resistance I will back the strings of on these.

Steve

Yes. This. I did break a truss rod in a nice bass once. Not a good day.

[Bruce Sexauer]

I do not create my fretboard with a flat surface. There is slightly more relief built into the bass side than the treble side. As long as the truss rod CA be adjusted under tension, that's the way to go. Otherwise you are just guessing and having to tension and slacken the strings repeatedly until you get there.

It is always a good idea to pull the neck back against the tension while adjusting the rod, that way you are not tightening the nut against the string tension, at least with any system I've used. Ten pounds of pressure against the nut while holding the body between the knee at the neck block and the ankle at the tail block works very well.

[H165]

On repairs, I do both. If the releif is extreme, I start with no string tension and adjust to absolutely flat. I then string up and adjust as Bruce describes above:

It is always a good idea to pull the neck back against the tension while adjusting the rod,

[ChrisN]

I'm no builder/luthier/tech. It seemed wrong to me to tighten a metal-to-metal connection (truss rod and nut) against 165 pounds of tension to bring the neck back, so I've typically loosened the strings 1 full turn, adjusted the rod, then tuned back to tension. I'll try Bruce's idea, next time, as it seems more convenient, quicker, and less wearing on the strings/nut.

[JayBee1404]

Originally Posted by ChrisN

I'm no builder/luthier/tech. It seemed wrong to me to tighten a metal-to-metal connection (truss rod and nut) against 165 pounds of tension to bring the neck back, so I've typically loosened the strings 1 full turn, adjusted the rod, then tuned back to tension. I'll try Bruce's idea, next time, as it seems more convenient, quicker, and less wearing on the strings/nut.

I did this yesterday. Changed strings on my HD-28V up a gauge from 12-54 to 13-56, the 12th fret action rose from 3 and 2 to 7/64” and 5/64” and the relief increased. I laid the guitar across my lap, pressed down on the nut, and tightened the rod a 1/4 turn in two 1/8-turn steps. No stress on the adjuster, turned easy and smooth. Back at 3 and 2 now, and the relief is back where I like it.

That’s the way I’ve tightened the rod in my guitars for a number of years, since my local luthier recommended to do it that way. Loosening, I just make the adjustment.

[Russ C]

I double what Bruce said.
You can bend an adjustable neck easily by hand - as long as you compensate for string tension the truss rod is not labouring and the job will be quick and accurate.
It’s always good to check you work later of course but that is not dependent on whether you loosened strings to do it.

[Fathand]

If a truss rod is tight, you can strip threads or break a rod. If the truss rod nut is not turning easily, I loosen strings, adjust, retune, repeat as needed.