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25.5 neck on a 24.75 body?

Polyester

Member
Messages
950
Yes I realize the answer is generally "no way". But I have a motley collection of guitar parts here, among which is a neat Gibson-scale bolt on body missing a neck, and a nice Fender neck.

My first thought was to just find a replacement bolt-on 24.75" scale neck, but being fairly broke right now, doing that without spending significant money is difficult.

So realizing that just bolting a 25.5" neck onto a 24.75" scale body is normally a terrible idea, would simply relocating the bridge ~3/8" backwards (or however much it would take for the appropriate scale length) take care of it? I have no problem doing so, but don't want to hack up the guitar only to find out it wouldn't work.

The bridge is a weird one piece string-through, sort of a hardtail Strat style bridge, so there isn't much to do other than the actual filling and redrilling. Otherwise I wouldn't even consider this.

Can it be just that easy though, or am I missing some vital detail that'll screw this whole thing up?
 

Structo

Member
Messages
9,555
The scale is determined by the neck and bridge placement.

The scale of the neck and placement of the frets are also different so I don't think you can simply move the bridge back.
Someone correct me if I'm wrong.

Warmoth makes conversion necks for this purpose.

Not sure about other companies making the conversion necks.

The Warmoth solution is expensive so you probably don't wan to go there.
http://www.warmoth.com/Guitar/necks/strat_conversionneck.aspx
 

Polyester

Member
Messages
950
I'm not talking about just moving the bridge back on a shorter-scale guitar to make it a 25.5" scale... that wouldn't work at all.

I'm talking about already having a 25.5" scale neck, and a body which originally had a 24.75" neck. If I mount the neck, and relocate the bridge to be 25.5" from the nut, that ought to work fine, right?

Might look a little strange but in my mind it should work without any problems. Proper scale length, frets in the right spots, etc.

Yes?
 

Kyle B

Silver Supporting Member
Messages
5,115
Can it be just that easy though, or am I missing some vital detail that'll screw this whole thing up?
Yes your supposition is correct. But your math is wrong.

25.5-24.75 = 0.75 = 3/4". If you only go 3/8" you won't ever be able to intonate. I guess you were thinking since you're combining two different scales, you'd "split the difference" and took the average. But that's wrong. Your goal is to turn the 24.75" body into a 25.5" body, so move the bridge back fully 3/4".

Note though, pickup locations aren't really random - they're sitting in tonal sweet spots. Sorta. Or at least that's what I've read - I've never built a sliding pickup jig to test that theory and see, but it does make sense that location would matter. Anyhow, it means unless you move your pickups also, you may get some unexpected tonal result. Who knows, it could be awesome :)

There's also the matter of the radius of the bridge should basically match the radius of the neck. A typical Gibson type tune-o-matic bridge (ala Les Paul) won't give you individual string height control like a Fender strat bridge would. You might need to grind down some of the saddles so they get shorter and match the Fender neck better.

Before drilling holes, I'd personally experiment to be absolutely sure I got the bridge placed correctly. You wouldn't want to drill holes, then discover you can't quite intonate because you need another 1/32" of travel on one of the saddles. If it's a tune-o-matic bridge, this shouldn't be too hard really. Pull the bridge out of the existing peg, and stick it in the place you think it should be. Shim it with cardboard or wood or something to get it the right height, and string the two E strings. The strings should hold the bridge down w/o it sliding around I think. Set the two saddles to their middle positions. Then intonate both the E's by sliding the bridge back & forth, and precisely mark the final position of the bridge. Note I've never done this :) It's just what I would try before committing to drill location.
 
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Clorenzo

Member
Messages
1,923
Yes your supposition is correct. But your math is wrong.

25.5-24.75 = 0.75 = 3/4". If you only go 3/8" you won't ever be able to intonate. I guess you were thinking since you're combining two different scales, you'd "split the difference" and took the average. But that's wrong. Your goal is to turn the 24.75" body into a 25.5" body, so move the bridge back fully 3/4".
This would only work if both necks had the same length from nut to heel, which is unlikely: if the neck ends at the same fret (say 21st), then the 25.5" one will be longer.

Install the new neck and then use this calculator to find out the correct bridge placement. Also, note that the Gibson scale length isn't actually 24.75" but 24.625", though there's been changes over the years (more info here). I've never heard of variations in the 25.5" scale, but just to be sure, the best thing to do is measure the distance from the fretboard side of the nut to the middle of the 12th fret and multiply by two. That's the number you should enter in the calculator.
 

dewey decibel

Member
Messages
10,855
I did this on my Duo Sonic project, Duo Sonic body with a Strat neck. Worked out fine. It's not likely but if the saddles on your bridge have enough play/travel you may not even need to move the bridge, you can measure to find out.

I did relocate the pickups, although that whole issue is fairly subjective.

Does your body have a Fender spec neck pocket? That would be what I'd worry about. Also keep in mind moving the bridge back isn't as easy as it sounds, I can go into detail if needed.
 

Polyester

Member
Messages
950
clorenzo / kyle b: thanks for that. Yeah, I didn't mean exactly 3/8"; I plan on getting the neck where it needs to go and then measuring for bridge positioning based on that. Somewhere around 3/8" most likely, but that's all depending on everything else.

dewey decibel: The neck pocket is definitely not Fender spec, but it's close enough that I can work with it. The width and depth are right, which is very good; the end of the pocket and/or the end of the neck need a little shaping to match but that's very doable.

First step is filling and redrilling the holes in the neck so this project isn't going to get done overnight, but if all works out it'll be a pretty nice Frankenstein guitar built out of old leftover parts. Semi hollow LP-style body plus comfy Strat neck plus three Rick-style toasters? Why not!
 

John Coloccia

Cold Supporting Member
Messages
9,584
Did you measure to see where everything ends up yet? For example, if the body was originally designed for a 21 fret neck and you have a 22 you may be all set. Definitely measure everything out before touching anything.
 

walterw

Platinum Supporting Member
Messages
39,374
measure from the leading edge of the nut to the center of the 12th fret; double that is where your hi E saddle should first contact the string. the other saddles will all be slightly behind that one, so line up the bridge with the hi E saddle extended out a bit.

can't say how good this'll be but it should work.

the other thing to consider is the relative value of the neck and the body; if one is nicer than the other, or is already drilled to "correct" fender specs, i'd leave it alone and alter the other one to fit it. (a warmoth neck say, onto a mis-fitting hondo body warrants redrilling the body, not the neck.)
 

Tone_Terrific

Silver Supporting Member
Messages
34,707
This is no different than locating the bridge on a new build 25.5 guitar.
Mount the neck, move the bridge into place and you'll be fine.
Easy...to say.
The pups are ok anywhere, they'll just sound a bit different.:banana
 

dewey decibel

Member
Messages
10,855
dewey decibel: The neck pocket is definitely not Fender spec, but it's close enough that I can work with it. The width and depth are right, which is very good; the end of the pocket and/or the end of the neck need a little shaping to match but that's very doable.

First step is filling and redrilling the holes in the neck so this project isn't going to get done overnight, but if all works out it'll be a pretty nice Frankenstein guitar built out of old leftover parts. Semi hollow LP-style body plus comfy Strat neck plus three Rick-style toasters? Why not!

Well what you've just said would make me nervous. Keep in mind how important things like neck angle are, and how when setting up a bolt-on guitar just a thin piece of business card in the neck pocket can change things. I'd be concerned about how big (thick?) the heal is and how high the fingerboard is going to end up in relation to the body. Maybe an issue, maybe nothing.

And when you're re-shaping things, if you do anything to the heal that's going to affect the placement of the bridge. IMO if you already have the body and neck laying around then I guess why not, but I wouldn't put any (or much) money into new parts for this project. IMHO!!!


This is no different than locating the bridge on a new build 25.5 guitar.
Mount the neck, move the bridge into place and you'll be fine.
Easy...to say.
Wanted to add, when you do this string up both high and low 'E' strings and try and get a little tension on them so you're sure to mount the bridge in it's correct position horizontally (or vertically? Depends how you look at it I guess...).
 

Polyester

Member
Messages
950
Well what you've just said would make me nervous. Keep in mind how important things like neck angle are, and how when setting up a bolt-on guitar just a thin piece of business card in the neck pocket can change things. I'd be concerned about how big (thick?) the heal is and how high the fingerboard is going to end up in relation to the body. Maybe an issue, maybe nothing.

And when you're re-shaping things, if you do anything to the heal that's going to affect the placement of the bridge. IMO if you already have the body and neck laying around then I guess why not, but I wouldn't put any (or much) money into new parts for this project. IMHO!!!

Wanted to add, when you do this string up both high and low 'E' strings and try and get a little tension on them so you're sure to mount the bridge in it's correct position horizontally (or vertically? Depends how you look at it I guess...).
I should probably mentioned I've fixed up and/or repaired many guitars, so I (hopefully) know my way around already. Converting a body to take a neck designed for a different scale is one thing I've not done before, hence the questions.

I should probably mention that these are all miscellaneous spare parts that have accumulated over time, and not one of 'em is worth any sort of money... so if I screw this all up, tossing them in the garbage and starting over is not going to hurt at all. Total investment so far: $0, possibly going as high as $10 if I'm not happy with the pots because I don't have any spare 250ks right now. It's going to be ugly and weird, but that just makes it more unique. :)

Test-mounting the bridge is not going to happen, though - I need to get it right on the first try or this whole project is boned. :omg The bridge is a weird, sort of hardtail Strat thing that mounts on two Gibson-style pegs. It does have independent Strat-style saddles though, so I can adjust them for radius and intonation and everything else. For being a cheap no name thing it's actually a pretty cool design.

So far the body has been stripped of its hardware and the bridge mounting studs have been pulled - they're some weird nonstandard size so I don't have the luxury of leaving them in for future un-conversion, but that's OK.

After cleaning up the neck pocket and measuring I'm ready to drill for the new bridge location... that's a project for the weekend though.
 






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