Max relief at 3rd/4th fret - a cure?

[antonius]

Hi there,

I would appreciate some advice. I love my 1975 4001 but it has an annoying problem. I have the neck as flat as I can get it but when I fret the first and last fret on the E string I can see that the point of maximum relief is at the 3rd - 4th fret instead of in the middle of the neck. I don't know if this means that most of the bowing of the next is taking place at around the 3rd/4th fret or if there is a slight dip here in an otherwise evenly bowing neck. It's only noticeable on the E side of the neck.

I try to ignore it but everywhere else on the otherwise flat neck feels great - except for this small area on the E string. When I'm playing I'm always conscious of the 3rd and 4th fret on the E string not feeling quite right due to the extra time and effort in fretting notes there and it's kind of distracting. It feels right for the action to be getting gradually higher further up the neck but it feels all wrong for it to be higher than it would normally be in this small area on the E string. Tightening the truss rods further is not an option because then I get a backbow further up the neck whilst not sorting out the problem area. I've also got the nut slot filed as low as I can get it to get the action as low as I can at that end of the neck to try to minimize it.

Has anyone else had this issue and is there a way to cure it? It seems like a small issue but if I could just eliminate or minimize it I'd be totally at one with my bass instead of trying to overcome this slight lingering annoyance at the back of my mind when I play. A Rickenbacker is an amazing instrument and I'm sure you guys understand the desire to unleash its full potential.

[cassius987]

With a 4001 any relief should be possible. You have done only manual adjustments right?

I tend to notice that when a guitar neck is really close to flat, the curvature is the most prominent closer to the nut. I actually like this because it kills off fret buzz at a point where the guitar would otherwise be predisposed.

[antonius]

With a 4001 any relief should be possible. You have done only manual adjustments right?

I tend to notice that when a guitar neck is really close to flat, the curvature is the most prominent closer to the nut. I actually like this because it kills off fret buzz at a point where the guitar would otherwise be predisposed.

Thanks for your input. Yes I've adjusted the rods correctly. But this localised bowing or dip exists not matter how I adjust the rods (lots of relief or very little relief elsewhere on the neck) and the worst frets for buzzing tendency are the 4th and 5th frets of the E string so it's not helping with that...

[T.A.R.]

Is there twist?

[antonius]

Is there twist?

No the neck isn't twisted.

[antipodean]

It could be that the rods are slightly misshapen (i.e. bent) near the top of the neck due to incorrect adjustment in the deep past. The rods can be removed and reshaped (you might want to get an expert to do this). In the event that the neck is kinked such that the reshaped rods can't adjust the relief out, a heat treatment may correct this.....

[antonius]

It could be that the rods are slightly misshapen (i.e. bent) near the top of the neck due to incorrect adjustment in the deep past. The rods can be removed and reshaped (you might want to get an expert to do this). In the event that the neck is kinked such that the reshaped rods can't adjust the relief out, a heat treatment may correct this.....

I've had the rods out and cleaned them up etc. They have always been totally straight.

What does heat treatment involve and is it risky? Heat lamps and some sort of jig/clamps holding the neck straight? Is there a less drastic solution? Is there any point in leaving it clamped for a while but without the extreme heat? Or just leaving it with no strings or rod tension for a while and see if it settles back to where it should be? Obviously I don't know much about all this and won't do anything unless I know what I'm doing and not risking any damage.

Thanks all for your suggestions.

[jingle_jangle]

I tend to prefer that the old-style rods have an arc in them of 1-2" in the center, with the center of the arc facing up, before they're inserted and tensioned up. You may want to try this.

Heat-straightening involves using a bar heater to soften the glue joint between the fretboard and neck, as well as to make the wood more ductile, and then clamping the whole shebang up nice and stiff and straight and letting it cool down...trial and error, but usually with predictable results.

[T.A.R.]

Glad to hear it isn't twisted

[heinpete]

I had some similar problem on the neck of a 1983 brugundy 4003, which had a huge, dark "birdseye" (or at least some kind of branching area) on the 5th fret .
No matter what truss rod adjustment was done, the buzz there stayed, when playing 1st to 4th fret . Finally my German luthier did what he could to level the frets in that area, which helped in the end .

[antonius]

I tend to prefer that the old-style rods have an arc in them of 1-2" in the center, with the center of the arc facing up, before they're inserted and tensioned up. You may want to try this.

Heat-straightening involves using a bar heater to soften the glue joint between the fretboard and neck, as well as to make the wood more ductile, and then clamping the whole shebang up nice and stiff and straight and letting it cool down...trial and error, but usually with predictable results.

Paul, thanks for your input. I wasn't aware of the need for the rods to be curved, but it certainly makes sense. I guess the backwards tension will mean the rods have more energy stored and you don't have to tighten the nuts quite so much.

Anyway, I've taken the rods out and will attempt to gently bend them as you've suggested. I always clamp the fingerboard when getting the rods out/in but I guess this will be even more important now as I imagine they will be MUCH harder to get back in with the arc in. I hope I can do it without inadvertently straightening them again.

Another question. Would it be worthwile bending them slightly more towards the threaded end given that they weren't flattening the end of the neck as much as the middle of the neck? Or is it wiser to just give them an even and regular bend along the full length? And should I wait a day or two before putting them back in to let the neck stabilise in its current flat state?

The good news is that with the rods out the neck appears to be flat - with no sign of a dip or bow being centred around the 3rd/4th fret. If anything there may be just a very slight backbow centred at the middle of the neck. How I long for the day when I can play this bass with a nice flat neck...

Peter - yes I can see how levelling the frets would probably minimise the problem I'm having but I'm hoping not to have to get into anything irreversible unless there are no other options. I'm pleased your bass was make more playable in the end

Thanks

[johnallg]

The good news is that with the rods out the neck appears to be flat - with no sign of a dip or bow being centered around the 3rd/4th fret. If anything there may be just a very slight backbow centered at the middle of the neck. How I long for the day when I can play this bass with a nice flat neck...

Thanks

Good news and a good sign. I would suggest making sure there is nothing in the slot the rods sit it - bound up masking tape that came off the rods, glue, any other extraneous material. That the neck is flat with the rods out bodes well for a solution.

[antonius]

OK, I bent the rods so that they were raised about 1.5 inch in the middle, cleaned them up again, and put them back in. This was easier than I anticipated - but I'm REALLY glad I had the fretboard firmly clamped!! As I said before the neck was totally flat with with the rods out. But with the rods back in the bowing at 3rd/4th fret was back, even without the nuts on and no string tension . It must be something to do with the way the rods sit in the channels... But the channels seemed to be clean and smooth so this is a mystery... Needs some more thought... (and yes I do have the rods in the right way up!)

Anyway, I gradually increased string and rod tension over a few hours. The end result is that the bow is still greater under the 3rd/4th fret than in the middle of the neck but less pronounced than it was so I guess this is at least a partial success. Bending the rods seems to have given them a lot more power and I'm not having to tighten the nuts as much as before. Thanks everyone for your tips and encouragement. This is a great forum and, as always, I'm learning so much from you guys.

[scott_s]

Levelling the frets in a jig that simulates string tension would probably clear that up. I hate it when necks are perfectly straight without strings, but do wacky things with strings on.

- Scott