Tell me about truss rods

[Darren Kern]

Would you hesitate to buy a mandolin that had a non-adjustable rod?

[mandroid]

Martin guitars dont have adjustable truss rods, a square tube of steel.
appointments are like selling the sizzle, builders quality is another thing.
single or double acting truss rods is another decision to ponder...
seasoned wood with grain structure with balanced 'pull' as it ages , can do a lot.

old gibson text supporting trussrod installation , is the ability to use wood of lesser suitability..

I have 2 1921 A mandolins that gibson made. an A4 with, and a nickle plated trussrod cover to promote it, and a plain ol A without , both are still fine , thank you.

[ourgang]

Martin guitars DO have adjustable truss rods since around the mid to late 80's. This was the best and greatest improvement Martin made to their guitars. Should have been done years ago.

[Michael Lewis]

Regarding truss rods, it depends on what precisely makes up the structure of the neck. A short neck of moderately large girth often doesn't need any reinforcement, as the early gibson necks. The longer and thinner necks that are more common today probably do need some reinforcement to maintain proper confirmation. In order to install a truss rod, a pocket must be cut for the adjusting nut. This is in the area near the thinnest part of the neck, which makes it a rather fragile structure, though it does allow some adjustment of the neck. On the other hand one can use a solid reinforcement bar(square steel tube, carbon fiber, hard aluminum, etc.) that extends into the headstock and greatly strengthens this area. If a non adjustable reinforced neck is properly made it should not need any adjustment throughout it's long life. It just depends on how the neck is designed and how the design is carried out. Over the last 20 odd years I have adjusted maybe a dozen mandolin necks and hundreds of guitar necks. Mandolins seldom if ever need to be adjusted.

[Steven Stone]

[Martin guitars DO have adjustable truss rods since around the mid to late 80's. This was the best and greatest improvement Martin made to their guitars. Should have been done years ago.]

Ahhh.....no.

Adjustable truss rods are very different than the original steel t-bar truss rod design used during the golden era of Martin instruments. They have a radically different mass and create a different sounding instrument. If you prefer to trade-off convenience for sound, then, yes, they are an improvement.

I'm sure several of the repair guys could supply more info, but IMHO the earliest adjustable truss-rod Martins have approximately the same incidence of needing neck resets as pre adjustable truss rod examples.

Many 30's, 40's, 50's, 60's, and 70's Gibsons flattops have needed neck resets and they all have adjustable truss rods. Also many Gibsons have needed repair for stripped adjustable truss rods.

Although the adj truss rod allows for minor neck relief adjustments, far too many users try to correct severe neck problems via the truss rods, with dire results - broken and stripped rods.

No, the best improvment Martin made to their gutiars was to try to create instruments as similar to their late '30's incarnations as possible, that and leave the guitars set up in the factory for 10 days to settle in, and then re-set them up before shipping them out,

[Will Kimble]

I don't believe truss rods would have anything to do with the incidence of neck resets. #Seems to be a flaw in the Martin dovetail design that we have been putting up with for a long time. #They just seem to require a neck reset every 20 years or so...

And I'm not sure the Martin comparison applies for mandolins, since Loar-era mandolins have adjustable truss rods.

I DO believe that changes in truss rod design can change the tone...

And for what its worth, I like adjustable truss rods on mandolins. #But I wouldn't hesitate to buy a Heiden or any other well built mandolin just because it did not have an adjustable truss rod. #

Will Kimble

[sunburst]

I don't believe truss rods would have anything to do with the incidence of neck resets. Seems to be a flaw in the Martin dovetail design that we have been putting up with for a long time. They just seem to require a neck reset every 20 years or so...
True enough, the truss rod in a guitar or mandolin neck doesn't really have much to do with whether or not the instrument does or will need a neck reset. The truss rod is there to keep the neck straight. If an instrument needs a neck reset, it is because of an incorrect angle to the body, and that angle will be incorrect whether the neck is straight or not.

The dovetail joint in a Martin guitar doesn't have much to do with it either.
Twenty years (or so) of string tension can deform the whole structure of a guitar body enough to change the angle of the neck enough to make a neck set needed, while the dovetail remains intact and tight. It could be any neck joint and the same thing would happen. Anyone who has done very many neck resets on Martin guitars can testify to the sweat on the work bench from the forhead of the luthier after removing some of the stubborn ones! Nothing wrong with those dovetails!
A poor neck joint can be the cause of the need for a neck reset, but it's not usually the case.

Martin and Gibson use different types of truss rod systems in their guitars, and each works differently. Neither will correct an improper neck angle to the body, so neither has much to do with the likelyhood of the guitars eventually needing neck sets. Either type can be damaged by missuse, as can lots of things.
Whether or not there is a different sound from a guitar or mandolin with or without a truss rod in the neck, it sure can be a lot easier to get a good set-up on one that is adjustable, and a good set-up contributes to better sound.
I agree, Martin should have added adjustable truss rods years ago, and not just to keep their warrantee obligations lower, which is probably one of the main reasons they did it.