G&L tech resources: Necks & truss rods


The Bi-Cut neck, used by G&L between 1982 and mid-2006, is associated with 2 patents: US Pat. 4,528,886, filed January 14, 1985 and US Pat. 4,670,955, filed March 11, 1985. The first patent is more generic, the second focussed on the anchor pins and specification for the holes needed in both blanks. The idea is to cut a neck blank in half lengthwise, rout a curved channel for the single-action truss rod (see the previous page for its working), and glue the 2 halves together again. And although one would see a seam along the length of the neck, especially on the back side and even more so on necks with figure (see the 1998 ASAT ‘Classic III’ below), this glue surface makes the neck remarkable stable against warping. Note that a maple fingerboard is an integral part of the neck whereas the neck would be thinned the proper amount to glue on a non-maple fingerboard, typically ebony or rosewood. It is worth mentioning here that these glued-on fingerboards were a thin, curved veneer until early-1992 when BBE Sound, Inc. had just taken over. After a short transition period in which a thicker curved veneer was used (see the Climax Bass below), G&L had moved to a slab fingerboard, i.e. with a flat bottom, by end of 1993. This is understandable since much more wood is wasted with a concave bottomed fingerboard. Another notable thing is the so-called “Birthmark” on these necks. This is one of 2 holes drilled to seat position pins on the template used to affix the neck so it could be shaped. The one on the headstock would subsequently be filled with a walnut dowel whereas the one on the heel remained unfilled. The oldest instruments with a Bi-Cut Neck in my collection are a 1982 SC-1 w/DFV (guitar) and a 1982 1st style SB-2 (bass). A unique variant of this neck is the pre-BBE #5 (guitar) neck, covered under US Pat. 4,803,906, filed February 19, 1989 which has wings hanging over the edges at the heel, as can be seen on this ASAT w/Kahler and ebony fingerboard and ASAT w/#5 neck, both from 1986. In early-1997, the 3-bolt neck attachment was change into a multi-bolt attachment with coinciding new S/N format and placement. The youngest 3-bolt instruments in the collection are a 1997 ASAT Classic Custom (guitar) and L-1500 Custom (bass). This 1997 Invader Plus is only a couple of weeks younger than the ASAT Classic Custom but is likely a test mule since it is lacking a serial number. The aforementioned ASAT ‘Classic III’ is hence the oldest production 4-bolt guitar on this site. But it should be noted the L-5500, introduced at the end of 1993, is the first bass using a neck attachment with more than 3 bolts. The latest instrument in my collection with the Bi-Cut neck is this 2006 25th Anniversary model, but due to its mahogany, the split is much harder to discern.


Bi-Cut neck