If there is no tapping/clicking sound and the string is resting flush on the fret, the truss rod needs loosening to bring the strings away from the fretboard. There seems to be some confusion online and out there in the real world regarding the Bi-Flex truss rod-what it does and how it works. Remember, hard maple is an excellent neck wood. "turning down" tightens the truss rod. There is something stated in the video that I will echo here. A Bi-Flex Truss Rod Doesn't Consist of Two Rods, Then? There's no reason to freak out, but I do admit it is a tedious process. "turning up" loosens the truss rod. If the slot on your bass won’t fit an Allen wrench, you’ll need to get a tool designed for your bass, which you can find at music supply stores and online. Fender Musical Instruments Corporation. Step 3. The Bi-Flex truss rod is still a single rod, but it works in both directions. The rod is anchored at one end of the neck and has an accessible adjustment mechanism at the other end typically consisting of a nut that can be turned using a screwdriver or Allen wrench. I recently performed a truss rod adjustment on my Yamaha RBX170 electric bass which does have the truss rod adjustment hole at the heel. When turning the nut counterclockwise, however, you'll first run across a "neutral position" in which the mechanism isn't applying force in either direction, and then you will encounter renewed tightening as the rod pushes against a walnut dowel near the nut, bowing the neck bow forward and thus correcting convex or "humped" neck relief. There are "dual-action" truss rods that do in fact consist of double rods, but the Bi-Flex system uses only a single truss rod. The general advice is to give a 1/8 turn. Fender also offers a double action truss rod adjustment wheel on all American Elite models that makes it a snap to address neck relief. How much should you loosen? Affix a capo at the first fret and depress the fourth string at the last fret. Because I have made the mistake before of making a truss rod adjustment, checking relief, adjusting again, being satisfied with the relief only to find it not set right when I check it the next day. "Turning up" is a counterclockwise turn that would loosen the truss rod and would bring the strings away from the fretboard. There's no reason to freak out, but I do admit it … This style of truss rod adjustment, be it on a vintage style Stratocaster, Telecaster, Jazzmaster, Jaguar, Precision Bass or Jazz Bass freaks people out because the neck has to come off in order to make a truss rod adjustment. This style of truss rod adjustment, be it on a vintage style Stratocaster, Telecaster, Jazzmaster, Jaguar, Precision Bass or Jazz Bass freaks people out because the neck has to come off in order to make a truss rod adjustment. Changes in temperature, pressure, and humidity can cause the wood to bend. Truss Rod Tip: Some bass guitars will have specific tools designed to adjust the truss rod. Problem solved. But since basses rarely need counterclockwise truss rod adjustment, more powerful single-action truss rods with a larger diameter replaced Bi-Flex truss rods in Fender basses. It can correct concave neck bowing just as a single-action truss rod does, but it can also be adjusted in the opposite direction to correct convex neck bowing. Skip to 4:05 to see this process in action. Step 5. What exactly is the Bi-Flex truss rod, and what does it do? "turning right" a.k.a. Fender designers remedied this situation by setting a small truss rod retainer fitting into the neck just beneath the seventh-fret fingerboard inlay (you can see the screw that holds it in place if you pop out the inlay).