Question about necessary fretboard width in connection with Bridge Spacing
 

Hello. New. First post. So I have an Eastman that has a 1 3/4 nut and bridge string spacing of 2 5/32. However, I used to own a Martin 000-28ec (during better times) that had a 1 3/4 nut and 2 1/4 bridge string spacing. And since I play fingerstyle, these specs were a dream. So, I'd like to replace the bridge on my Eastman with a bridge that has 2 1/4 bridge string spacing. However, I noticed that on the fourteenth fret (where the neck meets the body) on my Martin matched the width of its bridge string spacing. And I notice the same for my Eastman. So I am worried that if I replace the bridge on my Eastman to that of one with 2 1/4 bridge string spacing, the neck won't be wide enough to support it. The strings would be way too close to the edge of the fretboard. So, all that to simply ask, can put a 2 1/4 bridge string spacing bridge on my Eastman? Or just start saving for another Martin.

A thought
 

A ruler, masking tape, and a yardstick will let OP see what is possible. No way for correspondents to judge. Replacing a bridge ain't pocket change, too.

Local luthier here in California said it could be done over the phone. Just wanted see what some of you out there think. If you don't know, you don't know.

Also Luthier also said it would be $150 to relace the bridge. That's pretty cheap for me. And to gain those specs, I'd certainly pay it.

Correction: Replace the bridge.....

I've been following this post to learn something and expect someone with experience will shed some light on what you are considering. My first thought would be since the bridge pin holes won't line up, the bridge pin fit will be degraded. Maybe not enough to matter and possibly if reamed for larger diameter pins it would be ok, but I would like to hear a luthiers opinion.

The second concern is the string path is no longer parallel to the edge of the fret board and might not feel right capering the treble E at the higher frets, possibly pulling a string into the fret bevel (or over the edge). So I think you have answered your own question and the change would not be for the better.

I think an important thing to look at is how close the treble E currently is to the edge of the fingerboard. If you want to increase the string spacing by 3/32, that bumps out the high E 3/64 from the center of the saddle and 3/128 closer to the edge of the fingerboard at the 12th fret. A pretty minimal amount but if the high E is already riding close to the edge it might be too much.

It is definitely not a safe assumption that the low and high E's are equal distances from the edge of the fingerboard so it's something you (or the luthier) would have to check. Additionally take a look at how much room you have on the frets towards the edge of the fingerboard -- depending on how the fret ends are finished (beveled, rounded, etc.) you might have more or less room to work with.

All the more reasons to defer judgement until a luthier has made a hands-on inspection. No one but the person doing the inspection will be able to speak to the viability and expense of the project.

RHayes and IndianHillMike, thanks so much for your great insight. This was exactly the analysis I was looking for when I posted. I will definitely look into the points you raised and take a closer look at what you referenced. You guys are awesome!

If you want to see if the wider spacing is suitable for you, you can lightly notch the saddle to have the spacing you want. It will be very clear to you and you risk nothing but a saddle. You may even like the notched saddle--apparently Norman Blake does. Bill

bisco1, you know, that just might be the trick! It's definitely worth a shot. Thanks so much!

In general, the bridge spacing can be 1/16" more than the neck width at the 12th fret without issues. Whether you can go further will depend on how beveled the frets are, and how rolled the edges of the fretboard are. That reduces the effective width of the neck.

What I would suggest is to use kite string and at the bridge stick down some masking tape and draw the two center points for both low and high E-strings at your new string spacing. Then put the string in the E nut slot and pull it tight to where your new bridge pin hole markings are and observe what it looks like over the fretboard. As John mentioned if your fret ends are beveled and rolled you might need a whole fret job to get this right.

$150 bucks is a good price for such work because not only do you need a new bridge but they will have to plug the bridge plate and old holes too.