Quick question on string tension and neck relief?

lovestrat74

If the truss rod is backed right off does that increase the string tension on the guitar. We are talking Tele here, so no trem system to complicate the issue.

Basically, are you asking the strings to do more work getting the neck relief to where you want it to be with a loosened truss rod or have I got this the wrong way round? Or.. does this have no bearing on string tension whatsoever?

vonLayzonfon

I think...

The strings will put a certain amount of force on the neck when tuned to pitch. This may or may not have an effect on the bow of the neck, depending on how stiff it is, but probably exerts a small forward pull. So you may or may not need to use the truss rod to get the relief you want. 

francer

I think ...
Relief is increased by front bow, so if the truss rod is backed off (loose) you have your max relief already from the strings, only heavier strings would increase it. On a tele truss rod resists string pull on the neck and reduces bow or even adds backbow (reducing relief).

I don't think it affects string tension at all, if a string is tuned to pitch the tension is the same regardless of it's effect on the bow of the neck. So the string tension is fixed and the truss rod adjustment changes how much of that tension is shared between the rod and the neck itself.

springhead

String tension will stay the same regardless of neck relief - it's a function of scale length, string type/gauge and pitch.  With greater relief, or higher action - i.e. strings further away from frets, then you have to displace the string further in order to fret it which will make it feel stiffer.  Not the same as tension but it's easy to think of the string as being more taut as your fingers are working harder to play it.

merciful-evans

springhead said:

String tension will stay the same regardless of neck relief - it's a function of scale length, string type/gauge and pitch.  

Yep. This.

lovestrat74

So... 2 different Tele necks, same scale, same radius, same frets same relief, same action will have the same tension... The difference must be down to the action in my case then.

vonLayzonfon

lovestrat74 said:

So... 2 different Tele necks, same scale, same radius, same frets same relief, same action will have the same tension... The difference must be down to the action in my case then.

You forgot 'same string guage' but yes, basically. 

richardhomer

lovestrat74 said:

So... 2 different Tele necks, same scale, same radius, same frets same relief, same action will have the same tension... The difference must be down to the action in my case then.

I have played certain guitars (notably Eric Johnson Signature Strats) which feel harder to bend on that other variants. There are probably many reasons why (nut height, fret height, fret finishing, action, relief, etc) but I wonder if necks which have more (or less) ‘give’ play a part as well?

Clearly the tension for the same gauge and make of string ‘must’ be the same, if they are tuned to the same note - but the subjective difference in feel suggests something is going on.

Modellista

Actually there will be a slight change of scale length between a dead-straight neck and one that has a bow in it.  Imagine if you bend a straight thing the distance between the two ends becomes less.  We're probably talking fractions of a mm though.  

springhead

The different 'feel' is the effort required to displace the string from unfretted to fretted, or fretted to bent.  So height of the string above the board as already mentioned but also, particularly when bending, the amount of string behind the nut and saddle and the break angle at each end.  Hence owners of Les Paul/335's with separate tailpiece and bridge can raise or lower the tailpiece to change that 'feel', the resistance to string displacement.  Or some screw the tailpiece down for perceived tonal benefit but the top-wrap to make it feel easier to play. 

For strats and tele's then if if the scale length, string type and gauge, action and relief etc. are the same then I guess break angle over the nut could be a reason for different feel?  String tree height, method of wrapping the string round the tuner? 

FelineGuitars

lovestrat74 said:

So... 2 different Tele necks, same scale, same radius, same frets same relief, same action will have the same tension... The difference must be down to the action in my case then.

@lovestrat74 ;;

A string stretched over a set distance to a certain pitch will pretty much have the same tension (laws of physics)

The relief will only affect how it feels to get the string down t the fret top

There are a couple of other factors that can affect the feel of the tension in two identical scale teles and it has to do with the break angle of the strings at both ends.

Where the string comes down behind the bridge saddle can vary a bit , and also the angle the string comes down behind the nut too. Some Fenders have a deeper scoop on the headstock and that can create a greater angle over the nut.

So steeper = feeling more tense 

EDIT- I've just seen that springhead summed that up nicely while I was slowly composing an answer.

Funkfingers

For the most commonly used neck woods and profiles, string tension has the effect of creating a bow curvature between the nodal points at each end of the sounding portion of the strings. (The nut and the bridge.) The purpose of the truss rod is to counteract string tension.

Reducing the truss rod tension allows the string tension to have a greater effect on the bow in the neck. 

Correct adjustment is a balancing act between truss rod and your chosen string gauges.

On an electric guitar with a vibrato bridge, there is a further tension balance to be achieved between string tension and the vibrato springs.



NOTE: I have deliberately kept my comments general. For more precise suggestions, it helps to name the exact make and model of guitar under discussion in your opening post. Even knowing which end of the neck the truss rod adjuster appears at is relevant.

Clarky

lovestrat74 said:

If the truss rod is backed right off does that increase the string tension on the guitar. We are talking Tele here, so no trem system to complicate the issue.

Basically, are you asking the strings to do more work getting the neck relief to where you want it to be with a loosened truss rod or have I got this the wrong way round? Or.. does this have no bearing on string tension whatsoever?

when the trussrod straightens the neck's curvature, the neck will lengthen..
but not by a lot.. just a tiny amount..
if it lengthens enough to make you need to reset the intonation from the bridge saddles, then the string length and so the tension should go back to roughly what it was before..
so no... it shouldn't make any noticeable difference [provided the string gauge and tuning remain the same]..

HAL9000

FelineGuitars said:

There are a couple of other factors that can affect the feel of the tension in two identical scale teles and it has to do with the break angle of the strings at both ends.

Where the string comes down behind the bridge saddle can vary a bit , and also the angle the string comes down behind the nut too. Some Fenders have a deeper scoop on the headstock and that can create a greater angle over the nut.

So steeper = feeling more tense.

^Definitely this. I used to own a Tele with a toploader bridge which felt noticeably 'slinkier' than the normal string-through affair.

lovestrat74

Hmm... very interesting. Thanks chaps