Bowing neck on USA JB-2 bass.

[wally92860]

A couple of years ago, I bought a used G&L USA JB-2 bass. Lately, the neck has started bowing severely. I have taken my bass to a guitar tech who is familiar with G&L guitars and basses. He is unable to straighten the neck. The truss rod feels like it is at the end of it's adjustment. When the strings are loosened, the neck goes to it's normal position. Once the strings are tightened, the bowing returns. I really love this guitar and would appreciate any assistance you can give. Thanks!

[Ken Baker]

I've moved this to the G&L Bass forum because Paul's Technicalities is more about electronics.

Is the neck Bi-Cut (pre-CNC) or do you know the neck and/or body dates? The dates would be visible if you've removed the neck. If the neck is Bi-Cut you may be able to see a joint on the back of the neck from the heel through the headstock. I ask because this bowing you describe, a forward bow, is an indicator of a trussrod that has run out of adjustment (as you say) or is not adjusting at all. If you can't tell if the neck is Bi-Cut, please post a clear picture of the back of the headstock (or the front if not painted) and we may be able to see the joint.

CNC era trussrods work differently than the older ones and theoretically can't run out of adjustment.

If your neck is pre-CNC and you have the old style trussrod, try removing the adjuster nut and place a flat washer or two on the rod. Replace the nut and you should have at least some of your adjustment back.

Ken...

[wally92860]

Thanks for your quick reply. I copied your message and sent it to the guitar tech. Following your advice, he found that it is an older bass. The flat washers did not improve the neck enough to make it playable. Once again, when the strings are tightened, the bowing returns. I'm using regular gauge bass strings and tuning to E-flat. What should I do next?

[Ken Baker]

This sort of issue isn't really repairable if the washer method doesn't work, as the trussrod is built into the neck during the glue-up process after the Bi-Cut. Replacement is necessary. You can check the usual used sources; eBay, Reverb, et al, or contact G&L Repairs for availability and a quote. Call 714-897-6766 x156 or send an email.

Ken...