From larr–(at)–erakusa.com Wed Jun 28 00:18:49 CDT 1995
Article: 50552 of alt.guitar
From: larr–(at)–erakusa.com (Dr. Nuketopia)
Subject: The Myth of the Truss Rod.
Date: 27 Jun 1995 23:04:52 GMT
Organization: Merak Projects, Inc. (USA)
X-Newsreader: WinVN 0.99.3
I have never understood the mythology surrounding the truss rod. Lot’s of
myth and folklore surround the fine points of the truss rod, it’s purpose
The myth of the magic truss rod seems to be founded in the fact that not
many people know what it does. The truss rod adjustment is very simple.
All it does is change the relief in between the 4th and 9th frets on the
neck. This adjustment only needs to be done occasionally in a guitars
lifetime, or sometimes when making a substantial jump in string guages.
The truss adjustment is a *very fine* adjustment, measured in
thousandth’s of an inch. It’s the last part of a professional setup,
after the frets are leveled and the bridge height is properly adjusted.
To observe what the truss rod does, put capos on the 1st and the 12th
fret. Then notice the gap between the string and the top of 6th and 7th
frets. That distance is called the relief. There *should* be some gentle
bowing through that area. One uses a feeler guage to measure this
distance, which can vary between .003 to .015 inches or sometimes more.
Tightening the truss rod decreases this distance, loosening increases the
distance. Usually, no more than a 1/4 turn is needed to bring a neck into
a comfortable adjustment. Try it yourself if you like, and observe what
When the relief is very small, the neck is often described as being
“straight”. A relief measuring .009 is very common, and is the factory
setup on many guitars like stratocasters. Loosening the rod can eliminate
string buzzes in the middle frets, adjusting too loose can make the
action feel mushy through the middle frets. Tightening makes the action
lower, faster and slightly easier to play but can cause fret buzzing. You
have to strike a balance. Not all necks will adjust extremely straight,
many buzzes can’t be corrected by loosening. It is a very fine
Rules for truss adjustments:
1. It takes a couple of days for the adjustment to settle in sometimes.
Make small changes, then measure the instrument in a few days to see how
2. Measure the relief in the instrument’s playing position, strings in
tune, using the desired string gauge.
3. Never start by tightening a truss rod, always loosen it first to see
how tight it is.
4. Older instruments, collectables, adjusters that won’t easily turn, or
those that need more than small adjustment should always be taken to a
pro. You could have neck problems that need other forms of correction.
5. Use a feeler gauge to actually measure the adjustment, don’t just try
to sight it in.
6. Half a turn, max. If you need more, go see someone who knows. If
turning the adjuster doesn’t make a measurable change, take it to a pro.
7. Read Dan Erlewine’s book. Buy a straight edge and some feeler gauges.
8. Realize that careless adjustment or overtightening can ruin the
instrument or even break the truss rod. Be careful. When in doubt, see a
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