The Truss Rod



truss rod
The intent of a neck adjustment rod, or “Truss Rod” is to counteract the bending and compression of wood fibers due to forces (eg) guitar and bass strings, humidity, cold and heat on the neck. Would you believe that a set of electric guitar strings in the gauge of .010 - .046 when tuned to standard pitch at an average scale length of between 24.75” and 25.5”, and depending on the brand of strings can yield in the neighborhood of 100 lbs of continuous tension? By adjusting the Truss rod, we begin to generate and exert forces that help to lessen the tremendous stress applied to the neck wood by string tension and the weather.

The relentless humidity and heat of the Spring and Summer months can play havoc on stringed instruments. If the strings rattle , buzz or fret out…if you notice dead notes, if the action changes drastically, and/or the instrument will not intonate, it’s time to have the instrument evaluated by a qualified technician or professional Luthier. The aforementioned symptoms may indicate an over-adjusted truss rod. During the dry and cool fall and winter months when the neck wood was contracted, the adjustment was fine, but now that the weather has changed, it may be time relax the rod adjustment, and if the instrument has a screw-on neck, shims may have to be removed from the neck pocket. Here’s a simple check you can perform to see if the change of season and climate has affected your guitar’s neck.

Place the instrument on a flat surface, free of anything that could damage or mar the finish of the wood. First: The Bass side of the neck should be at eye level…you’ll be looking across the neck from side to side. Press the bass E string down on the first and last frets and then look at the middle of the neck. Ultimately, there should be a very small amount of space between the string and the frets…no more than about .015”, or about the thickness of a medium gauge guitar pick. If the strings are flat against the frets, it may be time for an adjustment to relieve some of the tension on the truss rod. Repeat this test using the G and high E strings. The amount of clearance across the neck when depressing the Low E, G, and High strings should be about equal. If let’s say….there is some string-fret clearance under the low E string, and there is NO clearance under the G or the High E string, it might indicate a twist or warp. If all this technical stuff interests you, then you need to attend one of my seminars. I am currently negotiating with The D’Addario String Company , and have asked them to co-host a string clinic and a basic guitar and bass set-up seminar in the early fall of 2009 at The Blue Moon, 114 South Broadway, South Amboy, NJ. You’ll get to see a real neck adjustment, and a good set-up. Don’t get any bright ideas though…I still won’t accept any responsibility if you mess up your instrument, and you’ll have to sign a disclaimer and waiver in order to attend.

Now….puleeez don’t log onto any guitar tool websites and buying yourself a neck adjustment tool just yet…there’s a lot more to properly adjusting a guitar neck than turning nuts, bolts and screws….and here’s where I print my disclaimer. I really hate to post shit like this, but you know what Humans do when they assume (make an ASS of U & Me) that things look and seem simpler than they are.

Disclaimer

Any attempt to change the setting on a stringed instrument neck adjustment rod or “Truss Rod” can permanently damage to the instrument. Improper adjustment of the rod can render the instrument unplayable, severely damage the neck AND the body joint in certain instances, break, or snap the truss rod, or even destroy an instrument neck. Master Luthier – Engineer George Goumas, the Fretshop, and The Fretworks warn explicitly against attempts to make adjustments to an instrument’s neck adjustment rod by un-trained and/or inexperienced persons. I will not accept any responsibility for damages incurred to an instrument by anyone other than myself. The bottom Line: Have your instrument neck adjusted by a trained, qualified technician or Luthier. I personally served a ten year plus apprenticeship with several of the finest luthiers in the country. I did not learn my craft through the purchase of “how to” videos and books.