Truss rods

[Mlazarus]

What year did Alembic switch from single truss rod to dual?

[jazzyvee]

Well, i have no idea when they started using two as standard, however you can still order an instrument with a single truss rod if you prefer.

[KR]

1977.

[Mlazarus]

Confirmed. 1977.

[hammer]

I have only one bass with a single truss rod.  The others are all dual. With both types the saying, "a little goes a long way" applies. One quarter turn and then give the neck a day or two to adapt before proceeding further (continue process as needed and don't get hung up on each dual rod needing to have exactly the same setting as the other).

[Mlazarus]

Of course each rod of the dual works independently? How do they work together?

[StephenR]

They are adjusted independently and work together to adjust the amount of relief in the neck. The only difference between dual- and single-truss rods is the number of truss rods, both systems are designed to achieve the same goal. Dual-truss rods just give you more control since one side of the neck can be adjusted slightly differently if it is necessary.

[adriaan]

You may also have heard of "dual action" trussrods, that you can adjust equally far towards forward bow as towards back bow. That's a different implementation altogether.

[Mlazarus]

I would think dual would make the neck stronger as well. The illusion of a very skinny neck seems to scare some people about breakage. Not that I'm going to sit on the middle between two chairs. Lol.