My son in law has a Yamaha ERB070-2. I think it's an entry level bass.

So a friend of his tunes up the bass. The pitch is way high, lots of extra tension, and it sets for a couple of weeks like that. He brought it over today to plug into my amp.

I tuned it down to pitch, but the neck had way too much relief.

I loosened the strings, removed the truss rod nut and gave it a drop of lubrication, replaced the nut and tried to put a bit of back bow in the neck by tightening the nut. No go. Then I clamped a bit of back bow into the neck (with a heavy board and spacers), then tightened the nut. It still would not put any back bow in the neck (it's almost exactly straight with no string tension). Then I added a washer underneath the nut, just in case it was running out of threads (one of those little washers they use on the tension rods on snare drums fit perfectly). No go. I just know the rod will snap somewhere if I try to tighten it much further.

The nut is not stripped - it tightens as it should, but the truss rod seems to be doing nothing.. does that mean it's broken? It doesn't rattle or anything like that when you try to play the bass. It just won't straighten the neck.

Is heating the neck an option?

I don't think the truss rod is broken, but sometimes you need to let it sit for a few days for the rod to take full effect on the wood. You say it's almost straight? why are you trying to put more backbow in it? you need relief in the neck. you should be able to fit a credit card smoothly between the 12th fret and the strings, as a laymans benchmark. If there is more than this, you may need to find a luthier with a heat press. But remember, heat pressing the neck is only a 50/50 proposition. It might work, it might not. You may have to check into a replacement neck if you can't get it squared away.
best of luck

I don't think the truss rod is broken, but sometimes you need to let it sit for a few days for the rod to take full effect on the wood. You say it's almost straight? why are you trying to put more backbow in it? you need relief in the neck. you should be able to fit a credit card smoothly between the 12th fret and the strings, as a laymans benchmark. If there is more than this, you may need to find a luthier with a heat press. But remember, heat pressing the neck is only a 50/50 proposition. It might work, it might not. You may have to check into a replacement neck if you can't get it squared away.
best of luck

I said it was almost straight (very slight up bow) with no string tension on the neck. Put string tension on the neck and it bows up like crazy. You generally need to start with a little bit of back bow to counter the string tension, so that you will end up with slight relief when tuned up to pitch, right?

That's a good tip on letting it sit for a few days. We didn't try that of course.

You generally need to start with a little bit of back bow to counter the string tension, so that you will end up with slight relief when tuned up to pitch, right?


Actually, no! My Carvin neck came to me pretty much straight as an arrow. there's no truss rod tension, no string tension, it's just straight.

Yes, for proper string action and playability you want just a tiny tiny little inward bow to the neck, but it definitely shouldn't be curving backwards when all tension is off the neck. When all tension is off the neck, it should be neutral, with no curve or bow at all.


This bass just might live to fight another day... as long as it doesn't twist! That's the real dealbreaker!

Actually, no! My Carvin neck came to me pretty much straight as an arrow. there's no truss rod tension, no string tension, it's just straight.

Yes, for proper string action and playability you want just a tiny tiny little inward bow to the neck, but it definitely shouldn't be curving backwards when all tension is off the neck. When all tension is off the neck, it should be neutral, with no curve or bow at all.


This bass just might live to fight another day... as long as it doesn't twist! That's the real dealbreaker!

Not sure if I agree with you. I would guess every neck is different. Even two supposedly identical necks coming off the assembly line right after the other, could be different as far as neck stiffness. I think most necks, if you just set the neck straight as an arrow with no string tension on it, would wind up with too much relief when tuned to pitch. On other necks, that may work just fine.

Yeah there's always the manufacturing variables. This isn't a hand-carved instrument, so it's gonna be a less-than-flawless piece of wood, so you're right. What kind of wood is the neck? Maple I assume? I know what happens when I assume.. heh heh...

How many days are you gonna wait before trying to restring it again?

You don't ever want to start with a back bow. You want the neck straight!!! Strng it up, and let it sit, develop the relief and then correct with the truss rod. If you start with a slight backbow, you lend yourself to torsional twist when strung up, because of the varying tension across the neck. It is always better to start flat.

You are correct about necks varying in stiffness, this is a fact that is ALMOST an absolute. You rarely find flexibility of equal resistance in different pieces of wood, even cut from the same board or flitch.

Start with a straight neck. OK, I'll try it, after it sets for a few days or a week. But I doubt this neck will ever have the correct amount of relief by starting with a straight neck.

If the truss rod doesn't have enough pull to straighten the neck, you are probably right, it will probably never have the correct amount of relief. Even if you back bow it, it will still come back to it's natural flex, and the relief wll be too much. Try contacting a Yamaha dealer or Yamaha themselves about a replacement neck, this might be your only recourse

If the truss rod doesn't have enough pull to straighten the neck, you are probably right, it will probably never have the correct amount of relief. Even if you back bow it, it will still come back to it's natural flex, and the relief wll be too much. Try contacting a Yamaha dealer or Yamaha themselves about a replacement neck, this might be your only recourse

Well, I really don't think the truss rod has enough pull, but I'm not giving up on it, yet.

It's not under warranty. He bought it used for $90. He doesn't play, just thought he liked the look of the bass and wanted it so he could learn on it. I played on it not long after he bought it, and it had too much refief then, but then his gorilla friend "tuned" it for him. Probably put an extra 50 or more pounds of pull on the neck, then left it that way.

If it needs a replacement, the only way it would be feasable cost-wise is to find a neck dirt cheap. It's not worth spending $150 on it. You'd be money ahead to simply go find another $90 bass with a better neck.

LMAO...Gorilla Friend....LMFAO that's good. I have seen Yamaha necks on Ebay go for $30 plus S&H, 2 of them last week. They are out there to be had. Good to hear you haven't given up. Sounds like me, fix it, or keep trying until it goes snap....LMAO of course, I have a shop to make a new one if it goes snap.....LOL I guess I hedge my bet there...

Good Luck on it, if I see a neck cheap that might fit it, I'll shoot you a PM

LMAO...Gorilla Friend....LMFAO that's good. I have seen Yamaha necks on Ebay go for $30 plus S&H, 2 of them last week. They are out there to be had. Good to hear you haven't given up. Sounds like me, fix it, or keep trying until it goes snap....LMAO of course, I have a shop to make a new one if it goes snap.....LOL I guess I hedge my bet there...

Good Luck on it, if I see a neck cheap that might fit it, I'll shoot you a PM

Thanks. Yeah, I just looked on ebay and saw a couple that had sold for cheap.

Bryan, I didn't mean to ignore you, sorry. It's a maple bolt-on neck with a rosewood fretboard. It's basically a P-style bass, but with a more modern look. I told him to loosen the strings and truss rod nut (it's back at his house now). We'll probably try again in a week.

No problem. Yeah, a standard P-Bass style neck with rosewood is extremely common. I'd bet money if you bought a neck from pretty much any manufacturer, it'd work. Maybe redrill new holes for the mounting screws, or a bit of sanding/cutting to fit the pocket right, but even if you get a neck that doesn't fit right, it's a learning experience! You'll most likely use that knowledge some time down the line, so try this project no matter what.