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While changing the strings on my MusicMan Sterling bass, I noticed the neck has developed a bit of a back bow. It's unplayable at the moment.



It has a truss rod adjuster at the body joint like so:



Never having touched a truss rod before, I have two questions.

1) Can I adjust this myself? Which way should I be turning the adjuster?

2) Why does this happen? It's been sitting in the case with strings on (yeah, I know) for about a year in a room with some temperature swings - not wild wild swings, but swings. Is that it? Humidity? Or can this sort of thing happen anyway? How should it be avoided?

Thanks. You rule. Yeah, you.

Stupid question: strings same gauge? Presumably they are. If not then that's why.

If strings are the same, then humidity/temperature can achieve the same awesome results. Also I've experienced sudden neck reactions to string-gauge changes way, way after the fact when something (humidity/temperature) has acted as the catalyst.

Answers:

1) Yes! It is ridiculous to pay for truss adjustments given the length of time it can take for even a small adjustment to take.

I've never adjusted one of those styles of truss but I would imagine that *edit*anti-clockwise*edit* (looking from body) will *edit*slacken*edit* the truss rod (the way you want to go).

You should be able to tell which way is tighten/untighten by feeling for more/less tension.

Never adjust a truss rod more than a 1/4 turn in 24 hours (I would give it longer).

You proverbial milage etc.

johnnyshape wrote:1) Can I adjust this myself? Which way should I be turning the adjuster?

2) Why does this happen? It's been sitting in the case with strings on (yeah, I know) for about a year in a room with some temperature swings - not wild wild swings, but swings. Is that it? Humidity? Or can this sort of thing happen anyway? How should it be avoided?

Thanks. You rule. Yeah, you.

1. you can, but if it's your first time, I'd suggest taking it to a tech that will let you watch / explain what is being done. a $30-50 trip to the tech is far cheaper than replacing the neck when you snap the rod. it does happen, i used to work at a guitar shop and uneducated folks did this more than expected.

Usually, but not always, it's clockwise to straighten the neck, counter clock wise to put "relief" in the neck.

2. it will definitely happen if you put on a heavier or lighter gauge of strings (more/less tension on the next) It can also be humidity. Can't really be avoided, you will probably need an adjustment or two (maybe more) a year depending on where you live/ the humidity.

if you wanna get into doing your own guitar tech work, I found this book to be really helpful when I started out:

http://www.amazon.com/Guitar-Player-Rep ... 0879302917

outoftune wrote:1. you can, but if it's your first time, I'd suggest taking it to a tech that will let you watch / explain what is being done.

I've been tweaking my truss (HAHAHAHA! IS RUDE!! HAHAHA!) since my first electric guitar (more than 20 years ago? can that be right) , and even though I made some early over adjustments (1/4 TURN ONLY! 1/4 TURN ONLY!) I've never, ever damaged a guitar.

You'd have to go truss-rod-crazy to fuck a neck up.

It seems like the answer is always, "Tighten the truss rod." When would be a time when the solution is loosening the truss rod?

Adam I wrote:I've never adjusted one of those styles of truss but I would imagine that clockwise (looking from body) will tighten the truss rod (the way you want to go).

You should be able to tell which way is tighten/untighten by feeling for more/less tension.

I should be tightening it? Isn't that to cure a bowed neck?

I just watched this video which seemed to suggest I should be loosening it to correct a back bow / 'rainbow'?

(confused face)

johnnyshape wrote:

Adam I wrote:I've never adjusted one of those styles of truss but I would imagine that clockwise (looking from body) will tighten the truss rod (the way you want to go).

You should be able to tell which way is tighten/untighten by feeling for more/less tension.

I should be tightening it? Isn't that to cure a bowed neck?

I just watched this video which seemed to suggest I should be loosening it to correct a back bow / 'rainbow'?

(confused face)

Yeah, really, really sorry - you're absolutely right.

I should completely refrain from posting (COMPLETELY?) on Sundays, given my ridiculous weekend work/sleep.

Still, advice stands as above, just slacken rather than tighten.

(slinks off feeling like a spaz)

skatingbasser wrote:It seems like the answer is always, "Tighten the truss rod." When would be a time when the solution is loosening the truss rod?

Trussrods are used to fight the pull of the strings, straightening the guitar's neck under full string tenson. If the neck is bowing forward, you will want the trussrod to do more work - tighten it. If you have backbow (like above), loosen he rod and let the strings do more pulling,

When you are tightening the trussrod, it's a good idea to loosen the stirngs. This helps the adjustment set more quickly. When adjusting my guitar, I got about 1/8 turn or so and wait 20 minutes. I tighten or loosen the rod from there. Conventional wisdom says wait 24 hours, but I have yet to much of a change after an hour or so. Minior adjustments seem to set pretty well after 20-30 minutes. This is a guitar though (SG). A thicker bass neck may be different. When loosening the rod, the adjustment should set fairly quickly.

[bad sleepless advice removed]

ubercat wrote:Back bow? Put stings on the bass, the same kind over and over. If that doesn't fix the bow thighten the truss little bits at a time

With backbow, he will want to LOOSEN the strings, not tighten them.

Tightening the trussrod on a neck with backbow will only make the issue worse. Tightening the rod fights the pull of strings, eventually forcing the neck backward with enough adjustment.