7 string dual truss rod neck questions!

Discussion in 'Luthier's Corner' started by benhardisme, Oct 25, 2004.

  1. benhardisme


    Mar 13, 2003
    ok.. this is my first try at luthierism. im making a neck through 7 string bass in my shop class. ive done a lot of research but i cant find much on dual truss rods. my questions so far are as follows:

    -should dual truss rods be parallel to the center or to the edges of the neck?
    -is it necessary to have a longer truss rod for a longer scale (35.5") or will a rod for a 34" work? if so would it be ok to have headstock access? i plan on having 29 frets which would kind of limit the option of body access.
    -my neck is huge - about 2.5" wide at the nut and 4" at the 24th fret (my exact measurements are at school). is there a rule of thumb for how far the truss rods should be from eachother and/or the sides of the neck in proportion to the width of the neck?

    thats pretty much all ive run into so far but it isnt unlikely i will be returning for more. thank you!
  2. FBB Custom

    FBB Custom TalkBass Pro Commercial User

    Jan 26, 2002
    Owner: FBB Bass Works
    This topic came up not long ago. Try searching for dual truss rods in this forum.

    Generally consensus was that you can have the rods aligned either way. Parallel to each other is easier to do, parallel to the edges might give you a slight advantage in terms of making relief adjustments.

    Using a 24" rod should not be a problem, and do peghead-side adjustment since you have so many frets. Of course, peghead-side adjustments will constrain your rod spacing options if you are going to make the rods parallel, and so it's a pretty good idea to do them parallel to the sides of th neck if you must do peghead-side adjust.

    There is no rule of thumb for spacing them except that how you do it will determine how aggressively you can carve the neck without carving through to the channels.
  3. benhardisme


    Mar 13, 2003
    thank you! i searched dual truss rod on several forums before i posted but nothing came up... only stuff that spoke of them but didnt say how they went about installing them. well sweet! im gonna order the rods tonight