How do you know if a truss rod is maxed ?

[njr911]

I set up my new P bass at the weekend. It's the first time I have ever done it so was a bit hesitant but most things went really well.

The bit I had most trepidation about was the truss rod. I measured the relief and it had a bit of a back bow.

Truss rod turned quite easily for a quarter of a turn, maybe a bit less, then felt stiff, so I didn't turn it any more and checked the relief again.

Slightly high but not too bad.

Played great all weekend. No issues at stage volume.

Playing it acoustically last night I have fret buzz on the 8 fret upwards. Not terrible but think I could do with less relief.

I'm now concerned that if I give the truss rod a shove it might be maxed and I'll do some damage.

The nut is at the body end and I have access so no neck off issues to worry about.

The nut sits flush with the body (should it ?)



Should I slacken the strings and help the neck with my knee while tightening the rod ?

Should I stop being silly with a £800 bass and give it to someone who knows what they are doing ?

[gadgie]

that's a great question.

[Thunderbird]

Sounds about maxed you know when it is to stiff to turn I would take it to a tech and see what they say if you f*** it up it will cost you dearly and a full set up should cost about 50 quid max

[njr911]

[quote name='Thunderbird' timestamp='1430912413' post='2765813']
Sounds about maxed you know when it is to stiff to turn I would take it to a tech and see what they say if you f*** it up it will cost you dearly and a full set up should cost about 50 quid max
[/quote]

Full set up from my luthier is £15. But I can do it all myself. It's just the truss rod but that's a pain

[icastle]

You really have to go some to break a truss rod.

If it's easy to turn then it's barely 'pulling' and you'll easily get another turn out of it.

[njr911]

[quote name='icastle' timestamp='1430917289' post='2765892']
You really have to go some to break a truss rod.

[/quote]

Ah man...you've just hexed me and I'm going to snap my rod now!

[Thunderbird]

[quote name='njr911' timestamp='1430913383' post='2765827']
Full set up from my luthier is £15. But I can do it all myself. It's just the truss rod but that's a pain
[/quote] blimey £15 is bloody good

[icastle]

[quote name='njr911' timestamp='1430917879' post='2765910']
Ah man...you've just hexed me and I'm going to snap my rod now!
[/quote]

One can only hope that's not a euphemism...

[PlungerModerno]

A few questions, to help clarify what has happened, and what is being discussed:

1. Is it a regular P bass? - i.e. a Mexican or USA Fender neck, with a 3/8ths inch hex adjustment? (If it is it means it's probably very durable).

2. You mention "Truss rod turned quite easily" but not which direction it was turned. I assume as it had back bow you loosened it? (anti-clockwise turn).

3. How are you approaching the setup? Action and relief are separate things - e.g. a neck can have a certain curve (relief) but have high or low action by adjusting bridge saddle height.

Here's one I've used with good results: [url="http://intl.fender.com/en-IE/support/articles/bass-guitar-setup-guide/"]http://intl.fender.com/en-IE/support/articles/bass-guitar-setup-guide/[/url]

[juliusmonk]

From your explanation, you had too much relief to begin with, then you tightened the truss rod and it naturally became stiffer - it's doing its job of countering string pull. This would have reduced the relief. Now, truss rod moves take a while to 'settle', so you found afterwards that you perhaps tightened it too much (therefore creating buzz due to no relief). If all that is so, you just have to undo what you did a bit - turn the other way a tad. If when you have proper relief action is too high, lower it at the bridge.

Or I may have understood nothing 😃

Edited May 6, 2015 by juliusmonk

[njr911]

Thanks all

Its a US P bass with hex adjustment. I got a 1/4 turn clockwise out of it easily before it became stiff. I thought it would only need 1/4 turn so left it at then and to see how it would settle.

Still needs a bit more so should I give it some welly!

[PlungerModerno]

Sorry for all the questions - I'm just trying to fully understand the situation you're having & how to avoid risking a pretty valuable instrument.

When you (in your last post) mentioned you [i]"got a 1/4 turn clockwise"[/i] it means you were adding tension or backward force to counteract string tension - however in the very first post you say [i]"I measured the relief and it had a bit of a back bow"[/i]. Clockwise turns on a regular fender truss rod will add to a backbow - not remedy it!

See pic:


Just to clarify - back bow is usually defined as when the neck "bows back" or has negative relief (on the side with the strings).
If the neck has a back bow - loosen the truss rod by going anti-clockwise.
IME it's good practice to check how tight (and how functional) a truss rod is by loosening it first (counter-clockwise for all but a few). If it's a double action truss rod (not in any fender I know of) you might want to sight the neck first - if it has lots of forward bow, "loosening" a double action truss rod may over tighten the nut in the opposite direction. A few turns should give you a clear impression either way. I would not use a whole lot of force - but you need to be firm with most truss rods. If I'm adding tension to a truss rod I typically loosen the strings a little - especially if they're higher tension (like 50 -110's tuned standard).

[njr911]

Thanks for clarifying - by back bow i meant, too much relief. Too bigger gap between 8th fret and strings, this is giving me a bit of fret buzz on 8th fret upwards.

I'll have another look at it this weekend, one I find my imperial hex key.

[PlungerModerno]

No probs - it's easy to get wires crossed via text - especially when both parties only know a bit about the things in question!

Do wait till you have the appropriate sized key. USA necks ususally have 3/16th inch hex truss rod nuts. The unfortunate thing is that while 3/16th inch is about 4.7 mm - it's just the right size to damage a 5 mm hex nut. 4 mm may be able to ring a 3/16ths nut - but It's harder to mistake.

[njr911]

[quote name='PlungerModerno' timestamp='1431073558' post='2767466']
No probs - it's easy to get wires crossed via text - especially when both parties only know a bit about the things in question!

Do wait till you have the appropriate sized key. USA necks ususally have 3/16th inch hex truss rod nuts. The unfortunate thing is that while 3/16th inch is about 4.7 mm - it's just the right size to damage a 5 mm hex nut. 4 mm may be able to ring a 3/16ths nut - but It's harder to mistake.
[/quote]

Thanks I need to buy one!

[njr911]

UPDATE!

My feeler gauges and imperial hex key set arrived yesterday so I had a play.

The good news is the truss rod isn't maxed, just a bit stiff which isn't surprising when you think about what it's actually trying to do with a big lump of wood.

I have now set the relief to .012

When I did that i then got buzzing all over the fret board so up with the action slightly.

It plays about right now, I'm still getting used to the zing and clank of roundwounds after playing on flats for the last 3 years.

I'm also still getting used to the different feel between a jazz bazz and a P as I have never played a P for any length of time before