4003 bass neck theory how it works/behaves?

[lumgimfong]

So it is two pieces with two trussrods.

Does the neck bend and respond to string changes as one piece?
Or does each side move a little independently?

[Gilmourisgod]

The theory behind two trussrods is that it allows a neck twist to be countered by having one rod tighter than the other. I believe Rick is the only manufacturer who currently uses two rods in a 4 string bass. You dont see two rods until you get into 6 strings with most builders. In practice, the best prevention for neck twist is well chosen, dry lumber, laminated with opposing grain so that any movement in one side tends to cancel out movement in the other. Ive never seen a Rick with neck twist, so whatever they are doing seems to work. The glue joint between the two pieces also adds a lot of strength by itself. The downside is the big truss rod adjustment pocket in the headstock, that a lot of wood missing at a high stress location. When Ricks break a headstock, that's where it happens, so don't drop it!

[jps]

...I believe Rick is the only manufacturer who currently uses two rods in a 4 string bass. You dont see two rods until you get into 6 strings with most builders....

Alembic has been using dual truss rods in their basses (and probably guitars) for decades. Both my '84 Exploiter and '87 Persuader had 2 rods.

[FabGearHead]

The thinking behind a two piece neck is that by having a center seam and two separate pieces of wood glued together, any stresses inherent to each piece are "relieved". Through the years the main neck issues I've encountered have been ship-mast-syndrome and s-curves, not twisting.

Twin truss rods are a great idea, especially for a bass with higher tension strings. Certain care must be used in making adjustments to avoid twisting the neck.

Jim

[Isaac]

"ship-mast-syndrome"?

[FabGearHead]

Yes, I was at a luthier symposium and Paul Reed Smith gave a great talk in which he explained that in many ways a guitar neck is acted upon by forces due to string tension and countered by fretboard stiffness, truss rod resistance and compression coupled with the extreme rigidity resulting from the neck being either bolted to or glued into the body. He said it was all directly corresponding to a ships' mast and he called it ship-mast-syndrome...

Jim

[jps]

Interesting thoughts by Paul, but I'm not sure syndrome is an appropriate descriptor for this. Makes it sound like there is a undesirable condition that my not be curable.

[FabGearHead]

You had to go... there?!?

Jim

[cassius987]

In my experience the rods mostly have the same effect on the relief of the whole neck rather than focusing their effect to one side, at least when string tension is being applied. A luthier I once worked with to fix an unlevel fingerboard on my 4003FL said the dual rods helped him to get everything level with minimal sanding.

On the whole I don't see many advantages of dual rods. Ironically, dual rods might weaken a neck by removing more wood to make room--but most of my Rics have incredibly stable necks (the 4003FL is the only one that ever needed seasonal adjustment) so if this is true, the dual rods more than compensate for it.

[FabGearHead]

Rhys, In my experience the lack of knowledge among Rick owners and some folks who tried adjusting the truss tods caused quite a few fingerboards to come loose for the first 3 or 4 frets. I repaired many of those and replaced a number of truss rods which were boogered at the threads or broken. You are correct about twisting and I never encountered any Rick with anything but a mild twist that was easily taken care of.

Jim

[wilmingtonian]

Is not an advantage of dual rods that adjustments can be made more to a player's liking - one rod tweaked to bring one side more in line to taste and somewhat independently of the other? I mean, not just an improved remedy to a potential neck twist?