Bowed neck??

Construction and repair of Classical Guitar and related instruments
Argent
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Bowed neck??

Post by Argent » Fri Dec 14, 2018 10:15 am

ImageI just listened to a very interesting podcast from the Classical Guitar Corner where New Jersey based luthier Garrett Lee was discussing guitar action, repairs etc with Simon Powis.

After listening I had a look at my own guitar. The neck does look noticeably concave in the middle. The action is fine for me and has been for years but I have had students try my guitar and complain it was more difficult to play than their own.


Should I be worried that my neck has progressively became more concave over time....?

I have attached some pictures but it is more noticeable in person.
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David Argent Cedar 2005

Stephen Eden
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Re: Bowed neck??

Post by Stephen Eden » Fri Dec 14, 2018 10:30 am

You do want a bit of bow in the neck but not too much. You can see and keep an eye on the relief by holding down the neck at the 12th fret and the first fret and looking at the gap around 5th and 6th frets. I usually aim for 0.25 - 0.4mm

If your action hasn't changed over the years it is unlikely your neck has moved forward. There also many factors that contribute to ease of playing not just action and relief.

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rinneby
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Re: Bowed neck??

Post by rinneby » Fri Dec 14, 2018 10:30 am

(Stephen beat me to it)

This is what's called "neck relief" and is something that must be present to avoid buzzing. However, yours seems to be rather noticeable. Hard to tell from a picture though. If you press 1st and 12th fret on the 6st string and tap fret 6-8 there should be a little "tick" and a small gap, but not large by any means. On the treble side 1st string, the same thing, but almost no gap is preferable.

/Jon
Last edited by rinneby on Fri Dec 14, 2018 4:32 pm, edited 1 time in total.
Feel free to ask me anything about Japanese classical guitars.

Argent
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Re: Bowed neck??

Post by Argent » Fri Dec 14, 2018 4:27 pm

Stephen Eden wrote:
Fri Dec 14, 2018 10:30 am
You do want a bit of bow in the neck but not too much. You can see and keep an eye on the relief by holding down the neck at the 12th fret and the first fret and looking at the gap around 5th and 6th frets. I usually aim for 0.25 - 0.4mm

If your action hasn't changed over the years it is unlikely your neck has moved forward. There also many factors that contribute to ease of playing not just action and relief.

I checked the action there at the 12th fret. It’s nearly at 5mm

When pushing the 12th and 1st fret it’s just over .5mm I would say at the 5th and 6th frets.

I only have a rubbish measuring tape so difficult to get an accurate measurement.


Like I say I can play the guitar no problem all day long.
David Argent Cedar 2005

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rinneby
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Re: Bowed neck??

Post by rinneby » Fri Dec 14, 2018 4:31 pm

Argent wrote:
Fri Dec 14, 2018 4:27 pm
Stephen Eden wrote:
Fri Dec 14, 2018 10:30 am
You do want a bit of bow in the neck but not too much. You can see and keep an eye on the relief by holding down the neck at the 12th fret and the first fret and looking at the gap around 5th and 6th frets. I usually aim for 0.25 - 0.4mm

If your action hasn't changed over the years it is unlikely your neck has moved forward. There also many factors that contribute to ease of playing not just action and relief.

I checked the action there at the 12th fret. It’s nearly at 5mm

When pushing the 12th and 1st fret it’s just over .5mm I would say at the 5th and 6th frets.

I only have a rubbish measuring tape so difficult to get an accurate measurement.


Like I say I can play the guitar no problem all day long.
How did you measure the action?

/J
Feel free to ask me anything about Japanese classical guitars.

Argent
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Re: Bowed neck??

Post by Argent » Fri Dec 14, 2018 4:33 pm

rinneby wrote:
Fri Dec 14, 2018 4:31 pm
Argent wrote:
Fri Dec 14, 2018 4:27 pm
Stephen Eden wrote:
Fri Dec 14, 2018 10:30 am
You do want a bit of bow in the neck but not too much. You can see and keep an eye on the relief by holding down the neck at the 12th fret and the first fret and looking at the gap around 5th and 6th frets. I usually aim for 0.25 - 0.4mm

If your action hasn't changed over the years it is unlikely your neck has moved forward. There also many factors that contribute to ease of playing not just action and relief.

I checked the action there at the 12th fret. It’s nearly at 5mm

When pushing the 12th and 1st fret it’s just over .5mm I would say at the 5th and 6th frets.

I only have a rubbish measuring tape so difficult to get an accurate measurement.


Like I say I can play the guitar no problem all day long.
How did you measure the action?

/J
The distance between the 6th string and the 12th fret
David Argent Cedar 2005

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rinneby
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Re: Bowed neck??

Post by rinneby » Fri Dec 14, 2018 4:40 pm

Argent wrote:
Fri Dec 14, 2018 4:33 pm
rinneby wrote:
Fri Dec 14, 2018 4:31 pm
Argent wrote:
Fri Dec 14, 2018 4:27 pm



I checked the action there at the 12th fret. It’s nearly at 5mm

When pushing the 12th and 1st fret it’s just over .5mm I would say at the 5th and 6th frets.

I only have a rubbish measuring tape so difficult to get an accurate measurement.


Like I say I can play the guitar no problem all day long.
How did you measure the action?

/J
The distance between the 6th string and the 12th fret
If measured from top of the fret to bottom of string, one could argue that the action is on the high side. 4-4.5 mm is more within "the norm" - But maybe you are a heavy hitter :) You are certainly not the first one.

/J
Feel free to ask me anything about Japanese classical guitars.

MessyTendon
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Re: Bowed neck??

Post by MessyTendon » Fri Dec 14, 2018 5:22 pm

It could be worse :) Enjoy it before the top sags and neck distorts.

Marshall Dixon
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Re: Bowed neck??

Post by Marshall Dixon » Fri Dec 14, 2018 5:24 pm

Argent wrote:
Fri Dec 14, 2018 4:27 pm
Stephen Eden wrote:
Fri Dec 14, 2018 10:30 am
You do want a bit of bow in the neck but not too much. You can see and keep an eye on the relief by holding down the neck at the 12th fret and the first fret and looking at the gap around 5th and 6th frets. I usually aim for 0.25 - 0.4mm

If your action hasn't changed over the years it is unlikely your neck has moved forward. There also many factors that contribute to ease of playing not just action and relief.

I checked the action there at the 12th fret. It’s nearly at 5mm

When pushing the 12th and 1st fret it’s just over .5mm I would say at the 5th and 6th frets.

I only have a rubbish measuring tape so difficult to get an accurate measurement.


Like I say I can play the guitar no problem all day long.
As noted 0.5 mm may be a little high.

Take a deck of playing cards. Measure the thickness of 50. Insert card(s) where you want to measure and do the math.

In the first picture you posted it appears that the 6th string is high at the nut, but looks OK in the second picture.

I've noticed that many guitarists from an electric guitar background are put off by the higher action of nylon strings. Classical guitarists that have a strong attack like it higher.

If you're comfortable with it then no reason to do anything.

Argent
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Re: Bowed neck??

Post by Argent » Fri Dec 14, 2018 7:27 pm

Marshall Dixon wrote:
Fri Dec 14, 2018 5:24 pm
Argent wrote:
Fri Dec 14, 2018 4:27 pm
Stephen Eden wrote:
Fri Dec 14, 2018 10:30 am
You do want a bit of bow in the neck but not too much. You can see and keep an eye on the relief by holding down the neck at the 12th fret and the first fret and looking at the gap around 5th and 6th frets. I usually aim for 0.25 - 0.4mm

If your action hasn't changed over the years it is unlikely your neck has moved forward. There also many factors that contribute to ease of playing not just action and relief.

I checked the action there at the 12th fret. It’s nearly at 5mm

When pushing the 12th and 1st fret it’s just over .5mm I would say at the 5th and 6th frets.

I only have a rubbish measuring tape so difficult to get an accurate measurement.


Like I say I can play the guitar no problem all day long.
As noted 0.5 mm may be a little high.

Take a deck of playing cards. Measure the thickness of 50. Insert card(s) where you want to measure and do the math.

In the first picture you posted it appears that the 6th string is high at the nut, but looks OK in the second picture.

I've noticed that many guitarists from an electric guitar background are put off by the higher action of nylon strings. Classical guitarists that have a strong attack like it higher.

If you're comfortable with it then no reason to do anything.
Thanks. I’ll give that a go. Yes I have no problem playing with that action and have never gave it a second thought before.It was just when I looked at the neck it looked odd to me.
David Argent Cedar 2005

baxialby
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Location: Italy

Re: Bowed neck??

Post by baxialby » Wed Jan 02, 2019 7:12 pm

Seems like it is bended due to lack of rigidity of the neck to the forces expressed by the tuned strings.
This shall never happen.

This can occour in 2 cases:

- the neck is not made pretensioned ( cheap industrial guitar, or guitar made by not expert luthier)

- the guitar is old and glueing is detached somewhere

simonm
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Re: Bowed neck??

Post by simonm » Wed Jan 02, 2019 8:02 pm

Argent wrote:
Fri Dec 14, 2018 4:27 pm
...
I only have a rubbish measuring tape so difficult to get an accurate measurement.
...
Like I say I can play the guitar no problem all day long.
Rubbish tape = rubbish measurements.

If you can play it all day, it is fine. It certainly doesn't look particularly odd to me in that photo.

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James Lister
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Re: Bowed neck??

Post by James Lister » Thu Jan 03, 2019 9:35 am

From that first photo, the relief looks excessive to me (more than 0.5mm), but it is difficult to be sure from a photo. If you can get a better measurement it would help.

James
James Lister, luthier, Sheffield UK

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