Loosening truss rod... neck still has backbow?

jenderfazz · #1 05-06-2006, 06:10 PM

I've been loosening the truss rod on my new 72 P since last night. Gave it a little more than a quarter turn yesterday, and another quarter turn or so this afternoon. I'm not a beginner when it comes to truss rod adjustments.

However, as much as I loosen it, the neck still has a slight bit of backbow (I like digging in and my strings buzz a bit near the first position). I turned it another half turn, counter clockwise as always, and am not seeing a difference. Any help?

pickles · #2 05-06-2006, 06:41 PM

I have seen examples where people use heat and clamps to try to chance the natural relief of a neck -- but there is an easy solution you might want to try: heavier strings. Especially since you say you like to dig in ... the higher tension will bring the relief up, and the strings will offer more resistance as well.

pkr2 · #3 05-07-2006, 06:20 AM

You may want to try tuning it about one note above standard and letting it set for a few hours. the extra tension may be enough to pull additional relief into the neck. Be sure to loosen the truss rod almost completely.

Be sure to tune it evenly across the strings to avoid introducing any twist in the neck.

Check the tuning very critically with a tuner when you get it over tuned and then check it occasionally to see if the tuning is dropping. A gradual drop in tuning is an indication that relief is actually increasing as it sets.

You can give a stubborn neck a little assistance by leaning the bass in a corner at about a 30 degree angle with the top of the bass facing outward.

Another way is to loosen the strings and put a short piece of dowel or about a 3 inch piece of broom handle under the strings at about the 7th fret and putting tension back on the strings. This puts a little "lift" on the headstock with the increased string angle and will put more bending force on the neck.

I would be very cautious with clamps and heat because of the danger of forcing a bend that doesn't describe a true arc. With a clamp, the bending force is concentrated in one spot on the neck and could cause a slight "kink" in the neck. Sort of like the profile of a pyramid.

Good luck.

justBrian · #4 05-07-2006, 11:24 AM

I have the opposite problem. I can't get the relief out of the neck. The trussrod is loosened almost all the way, the tension is off the strings, yet there is still a concave bow in the neck. Suggestions?

pkr2 · #5 05-07-2006, 01:01 PM

Quote:

Originally Posted by justBrian

I have the opposite problem. I can't get the relief out of the neck. The trussrod is loosened almost all the way, the tension is off the strings, yet there is still a concave bow in the neck. Suggestions?

Loosening the TR will put more relief in the neck. You need to tighten the TR nut. I'm assuming that you have a compression, or Fender type truss rod.

cerrem · #6 05-09-2006, 03:59 PM

Just my 2 cents...
When tightening a truss rod, to remove the relief...
Use you left hand/arm to pull the neck back at the headstock to where you want it while the body is secured with your right forearm while turning the screwdriver/allen wrench....then tighten the truss rod...This way the threads turn a lot smoother and less pressure against the nut and threads...
Chris

gfried84 · #7 05-10-2006, 08:59 PM

The only thing I can say is that maybe your rod is stuck on something in the neck. If it gets caught, it will not release and the neck will keep the backbow. I would remove the neck from the body and gently push the neck the way you want it to move. Sometimes this will free up the rod.

Akami · #8 05-10-2006, 11:47 PM

Quote:

Originally Posted by justBrian

I have the opposite problem. I can't get the relief out of the neck. The trussrod is loosened almost all the way, the tension is off the strings, yet there is still a concave bow in the neck. Suggestions?

Quote:

Originally Posted by cerrem

When tightening a truss rod, to remove the relief...
Use you left hand/arm to pull the neck back at the headstock to where you want it while the body is secured with your right forearm while turning the screwdriver/allen wrench....then tighten the truss rod...This way the threads turn a lot smoother and less pressure against the nut and threads...

This is the best way to do it, and yeah, the truss rod is for pulling back in the opposite direction of the strings, so tighten it.
I usually go 1/2 a turn at a time if it's way out and only 1/4 turn if your getting close.
Just worked on my new (to me) Sterling today and it's playing much better! Same problem you're having.

justBrian · #9 05-11-2006, 06:15 AM

Thanks for the replies-- I'm taking it to rehearsal tonight. One of the guys is a pretty good tech so we're going to look at it then. I'll keep you posted.
It's MIM jazz I picked up in trade. I refinished it--went from red to Fender Blonde (about 50% opacity) with a clear nitro finish. I stripped the neck and, tongue oil on the back and painted the headstock to match. Looks pretty badass now.

jenderfazz · #10 05-19-2006, 12:58 PM

Thanks for the replies as well. I tried tuning up a full step above standard, and even the same using a drumstick as a dowel... no dice. Maybe a larger dowel? All I know is the tuning barely dropped, if at all, and any neck change was reversed when I tuned down again. Any other suggestions?

Akami · #11 05-20-2006, 01:05 AM

I've done a lot of truss rod adjustments and have found several over the years that were just bad necks, but they were also usually cheap instruments to begin with.

The only one that stands out in my memory though was a MIJ Telecaster which was just unworkable. No matter what I did it was impossible to get any improvement and I worked on it for over 11 hours during the course of two days.

If this is the case the only thing to do would be to take it in to someone who is really good with neck problems.

Good luck.