Do I need to consider nut width when swapping the bridge on my JM?

[NateD81]

I've never replaced a bridge before so I would love some guidance!

I've got a 60th anniversary JM and planned to buy the Fender American pro jag / jm bridge (part # 7709942000 on darrenriley.com) to swap out the vintage one currently on there.

https://darrenriley.com/store/fender-am ... 709942000/

the nut width on my 60th anniversary is 40mm and the string spacing is 'flexible' as you all know. The American pro bridge has 2-1/16″ string spacing -- does anyone foresee this being an issue for my guitar? I really don't like the current bridge that's on there, sadly the staytrem is not an option, and I don't really have the cash to go the mastery route.

Lastly, if I can use this bridge with not string spacing / nut issues, will it drop in or do I need to consider new thimbles as well?

[timtam]

Riley's description of the Am Pro's Mustang-style bridge's string spacing as 2-1/16", which is 52.4mm, is likely wrong. Probably just a quick measurement with a ruler (Riley is usually pretty good at including important specs that Fender omits to provide). Given the number of people who reported E's falling off the edge of Am Pro fretboards or coming close, it's more likely to be around the standard 56mm.

As to whether that fixed spacing might be an issue for you, what is your preferred E-E spacing on your current vintage-style bridge ?

[NateD81]

Riley's description of the Am Pro's Mustang-style bridge's string spacing as 2-1/16", which is 52.4mm, is likely wrong. Probably just a quick measurement with a ruler. Given the number of people who reported E's falling off the edge of Am Pro fretboards, or coming close, it's more likely to be around the standard 56mm.

As to whether that fixed spacing might be an issue for you, what is your preferred E-E spacing on your current vintage-style bridge?

I’ll be totally honest and tell you that I’ve got no idea what my preferred spacing is, E to E, however, this is my first JM worthy his type of bridge (I’ve had a Squier JMJM, and an American Special hardtail). Both of those guitars had issues with the low E slipping off the fretboard which I did not like.

Currently, I really like how my spacing is set up, I really have no issues with the spacing, just problems with the typical vintage bridge setup which I why I really want to resolve that without a buzzstop if possible.

Is this image helpful at all? Sorry - I'm totally new to this and I'm trying to avoid spending $70 bucks if it's not going to be an improvement.

[timtam]

So your pic with the setup that works for you now is at 2 inches E-E spacing (50.8mm). If someone has the 7709942000 American Pro aftermarket bridge maybe they can help us with an exact E-E spacing measurement. But as I said there is a suspician that it's closer to 56mm than Riley quotes. If so, you could try that spacing by moving your E strings now out to 2.2" apart (56mm), and see if it still works for you.

But 52mm sounds like the best fixed spacing option for you. Staytrem (9.5" radius version for your JM) and Mastery are 52mm. Or the 7712971000 Marr bridge from Riley is supposedly 52mm (but 7.25" radius), but it's only just become available and AFAIK no one has taken delivery of one aftermarket yet to check that it has really got 52mm E-E spacing.

[NateD81]

So your pic with the setup that works for you now is at 2 inches E-E spacing (50.8mm). If someone has the 7709942000 American Pro aftermarket bridge maybe they can help us with an exact E-E spacing measurement. But as I said there is a suspician that it's closer to 56mm than Riley quotes. If so, you could try that spacing by moving your E strings now out to 2.2" apart (56mm), and see if it still works for you.

But 52mm sounds like the best fixed spacing option for you. Staytrem (9.5" radius version for your JM) and Mastery are 52mm. Or the 7712971000 Marr bridge from Riley is supposedly 52mm (but 7.25" radius), but it's only just become available and AFAIK no one has taken delivery of one aftermarket yet to check that it has really got 52mm E-E spacing.

This is super helpful! I'm going to first try adjusting the spacing as you suggested to see how that feels. I suspect I won't like it as much hah The Marr bridge sounds interesting - I think I read about it in the bridge super thread. Would it be incredibly awkward to have a 7.25 radius bridge on a 9.5" radius neck?

[Telemnemonics]

The often inaccurate sting spacing listed for Fender fit bridges is frustrating and often confusing until you buy and try.

WRT putting a 7.25 bridge on a 9.5 board, I would find that unacceptable, and we generally want a slightly flatter radius for the bridge to allow for gradually higher action across the wound strings which vibrate in a larger area so need more clearance over the frets.

You asked if nut spacing was a consideration, and I'd say it is a factor, where a narrower nut or a neck that's narrower at the nut will bring the strings in a bit at the upper end of the board.
Depending on your current nut width, you may be able to set it up with a narrower spaced nut to get a more comfortable bridge and fingerboard spacing overall.
But that would require a new nut. Might still be worth it if it allows you to use an available bridge that wasn't made of unobtanium in a NASA lab.

FWIW I have an original Mustang bridge on the bench and it's a solid 2 1/8" string spacing.
Your strings being moved in narrower to suit your preference suggests you won't like a 2 1/8"spacing.
Might help if you showed your string spacing at the 21st fret and the nut.
If you move the strings out at the bridge so they are centered on the saddles and measure 2 1/8", can you play the guitar?
Is the high E or the low E closer to the edge than the other E?
Are your fingerboard edges rolled so the frets are narrower on top?
Fender has buggered up a lot of expensive guitars by catering to the relic loving crowd with crazy rolled board edges that are almost unplayable.

Helps to identify exactly what the problem is when searching for a solution.

Edit: Sorry, I missed where you said your 60th Anny has a 40mm nut width.
Is that an accurate measurement? That would be 1 3/4", fairly huge compared to the more common 1 5/8" or 1 11/16".
A 1 3/4" nut width will be the cause of your problem here!

[NateD81]

The often inaccurate sting spacing listed for Fender fit bridges is frustrating and often confusing until you buy and try.

WRT putting a 7.25 bridge on a 9.5 board, I would find that unacceptable, and we generally want a slightly flatter radius for the bridge to allow for gradually higher action across the wound strings which vibrate in a larger area so need more clearance over the frets.

You asked if nut spacing was a consideration, and I'd say it is a factor, where a narrower nut or a neck that's narrower at the nut will bring the strings in a bit at the upper end of the board.
Depending on your current nut width, you may be able to set it up with a narrower spaced nut to get a more comfortable bridge and fingerboard spacing overall.
But that would require a new nut. Might still be worth it if it allows you to use an available bridge that wasn't made of unobtanium in a NASA lab.

FWIW I have an original Mustang bridge on the bench and it's a solid 2 1/8" string spacing.
Your strings being moved in narrower to suit your preference suggests you won't like a 2 1/8"spacing.
Might help if you showed your string spacing at the 21st fret and the nut.
If you move the strings out at the bridge so they are centered on the saddles and measure 2 1/8", can you play the guitar?
Is the high E or the low E closer to the edge than the other E?
Are your fingerboard edges rolled so the frets are narrower on top?
Fender has buggered up a lot of expensive guitars by catering to the relic loving crowd with crazy rolled board edges that are almost unplayable.

Helps to identify exactly what the problem is when searching for a solution.

Edit: Sorry, I missed where you said your 60th Anny has a 40mm nut width.
Is that an accurate measurement? That would be 1 3/4", fairly huge compared to the more common 1 5/8" or 1 11/16".
A 1 3/4" nut width will be the cause of your problem here!

I would be willing to have a different nut put on, but it'd definitely need to be done by someone who knows what they're doing because I would sure mess it up. In an ideal world, I would be able to find a bridge that could work without too many mods. My dad is a retired machinist and converted his garage to a machine shop, so he could modify the bridge if that is necessary, but the easier the better

I haven't moved the strings out yet, I plan on doing that this evening and will report back. I'm not the best technical player so I worry about having the E strings too close to the fretboard because I know I'll end of pushing them off too often.

as far as I can tell the fingerboard edges are not rolled - however - from the measurements in the pictures below it appears the frets are narrower on top.

Let me know if this helps at all. I can't thank you enough for sharing your expertise!

[Telemnemonics]

OK sorry, I have an odd antique German caliper with what appears to be CM/MM graduations that are something else entirely!
Maybe picas?
So you have a normal 1 5/8 nut and the string spacing is well inside, that's not an issue.
While Fender does tend to put the strings pretty close to the edges of the board on vintage USA spec guitars, if you really need narrower I'm not sure what product you can get that will work for you here.

Given that your Dad has a machine shop, maybe he can mill you up six custom saddles of the correct height, then you can get a guitar tech to groove them to your preferred width. Or the old man can groove them to where you set the strings.
Having a machinist on staff should get you where you want to go!

You could also have him mill a used Mustang bridge down so the grooves are gone, then mill new grooves at a narrower spacing.
Depending on neck angle and bridge height you may get away with that or the strings may hit the bridge sides before the low and high E saddle tops.

If there is a perfect bridge for your problem out there I'd think a member here would have suggested it.
Maybe ask in a new thread called "narrower JM bridge availability" or something like that?
Maybe just get used to strings closer to the edge...

[NateD81]

OK sorry, I have an odd antique German caliper with what appears to be CM/MM graduations that are something else entirely!
Maybe picas?
So you have a normal 1 5/8 nut and the string spacing is well inside, that's not an issue.
While Fender does tend to put the strings pretty close to the edges of the board on vintage USA spec guitars, if you really need narrower I'm not sure what product you can get that will work for you here.

Given that your Dad has a machine shop, maybe he can mill you up six custom saddles of the correct height, then you can get a guitar tech to groove them to your preferred width. Or the old man can groove them to where you set the strings.
Having a machinist on staff should get you where you want to go!

You could also have him mill a used Mustang bridge down so the grooves are gone, then mill new grooves at a narrower spacing.
Depending on neck angle and bridge height you may get away with that or the strings may hit the bridge sides before the low and high E saddle tops.

If there is a perfect bridge for your problem out there I'd think a member here would have suggested it.
Maybe ask in a new thread called "narrower JM bridge availability" or something like that?
Maybe just get used to strings closer to the edge...

Fair enough -- I think i'll just go with the closest possible bridge and modify if necessary and/or become a better guitar player! Thanks again for the input!

[timtam]

With your current ~2" (~51mm) E-E spacing your strings look to be nicely positioned in relation to the edge of the fretboard. You wouldn't want to go much wider. Your nut looks fine. So the new 7712971000 Marr bridge may be your best option (as of now yet to be confirmed as 52mm E-E). Only if its 7.25" radius proves to be an issue would you then consider flattening its radius a tad, by getting the middle string grooves filed down a fraction, or the middle saddle edge ridges filed off the bottom.

[NateD81]

With your current ~2" (~51mm) E-E spacing your strings look to be nicely positioned in relation to the edge of the fretboard. You wouldn't want to go much wider. Your nut looks fine. So the new 7712971000 Marr bridge may be your best option (as of now yet to be confirmed as 52mm E-E). Only if its 7.25" radius proves to be an issue would you then consider flattening its radius a tad, by getting the middle string grooves filed down a fraction, or the middle saddle edge ridges filed off the bottom.

I ended up finding a used, what I believe is the Fender American Professional bridge used on Reverb for 60 bucks so I’m just going to give it a shot. It came off the Triple Humbucker 60th anniv JM I thought I might try it. I figure if the E’s are off I can fix that in my dads machine shop, but hoping I won’t need to. If that doesn’t work out I’ll throw it back up on Reverb but if nothing else, I’ll post my results to help anyone with a similar situation.

[Telemnemonics]

With your current ~2" (~51mm) E-E spacing your strings look to be nicely positioned in relation to the edge of the fretboard. You wouldn't want to go much wider. Your nut looks fine. So the new 7712971000 Marr bridge may be your best option (as of now yet to be confirmed as 52mm E-E). Only if its 7.25" radius proves to be an issue would you then consider flattening its radius a tad, by getting the middle string grooves filed down a fraction, or the middle saddle edge ridges filed off the bottom.

Right, easy to mill off the bottoms of the middle saddles on a 7.25 bridge.
WRT the Marr bridge width, you could write to Stratosphere and ask them to measure it, but they never reply to questions I ask.

https://www.ebay.com/itm/2018-USA-Fende ... ctupt=true

[timtam]

WRT the Marr bridge width, you could write to Stratosphere and ask them to measure it, but they never reply to questions I ask.

There is a whole saga with respect to the Marr bridge that you may not have picked up on yet.
- the original Marr jags (incl. the parts Stratosphere are currently offering) have the 0091905000 bridge, which is ~56mm E-E (ie wider than the Staytrem's 52mm, some of whose other features it does have). So Stratosphere's offerings are not likely to be useful currently if a narrow spacing is desired.
- the new Lake Placid Blue version of the Marr guitar has been reported as having a 52mm spaced bridge (which most people prefer)
- that new bridge has become a 'hot' item since Staytrem stopped selling outside the UK recently
- it did not have a known part number, nor was it available aftermarket, until it appeared on the Riley site with the 7712971000 part number last week
- however Riley mistakenly currently calls it an Americian Professional / Marr bridge. As far was we know, that bridge has never appeared on an Am Pro (the true Am Pro bridge is 9.5" radius).
- Riley quotes it as having 2-3/32″ string spacing (53.2mm). Other features are consistent with the Marr bridges, original and new (eg nylon anti-sink bushings on the bridge height posts).
- some people ordered that bridge before it went out of stock, but are yet to receive it so we don't know for sure that it really does have the same narrower 52-53mm string spacing as the bridge on the LPB Marr guitar (Riley's measurements can be approximate at times).

Bridge issues are complicated in offset world.

[timtam]

I ended up finding a used, what I believe is the Fender American Professional bridge used on Reverb for 60 bucks so I’m just going to give it a shot. It came off the Triple Humbucker 60th anniv JM I thought I might try it. I figure if the E’s are off I can fix that in my dads machine shop, but hoping I won’t need to. If that doesn’t work out I’ll throw it back up on Reverb but if nothing else, I’ll post my results to help anyone with a similar situation.

Yes it looks like the 60th Anniv Triple JM has the 7709942000 Am Pro bridge. Hopefully it suits. The (harder) fix for too-wide string spacing is to drill new intonation screw holes in the other wall of the bridge plate that are 10.4mm apart, and shave off the sides of the saddles to allow the string grooves to also be 10.4mm apart (for 52mm E-E spacing ) instead of 11.2mm apart (with 56mm spacing).

[Telemnemonics]

WRT the Marr bridge width, you could write to Stratosphere and ask them to measure it, but they never reply to questions I ask.

There is a whole saga with respect to the Marr bridge that you may not have picked up on yet.
- the original Marr jags (incl. the parts Stratosphere are currently offering) have the 0091905000 bridge, which is ~56mm E-E (ie wider than the Staytrem's 52mm, some of whose other features it does have). So Stratosphere's offerings are not likely to be useful currently if a narrow spacing is desired.
- the new Lake Placid Blue version of the Marr guitar has been reported as having a 52mm spaced bridge (which most people prefer)
- that new bridge has become a 'hot' item since Staytrem stopped selling outside the UK recently
- it did not have a known part number, nor was it available aftermarket, until it appeared on the Riley site with the 7712971000 part number last week
- however Riley mistakenly currently calls it an Americian Professional / Marr bridge. As far was we know, that bridge has never appeared on an Am Pro (the true Am Pro bridge is 9.5" radius).
- Riley quotes it as having 2-3/32″ string spacing (53.2mm). Other features are consistent with the Marr bridges, original and new (eg nylon anti-sink bushings on the bridge height posts).
- some people ordered that bridge before it went out of stock, but are yet to receive it so we don't know for sure that it really does have the same narrower 52-53mm string spacing as the bridge on the LPB Marr guitar (Riley's measurements can be approximate at times).

Bridge issues are complicated in offset world.

Ahhh, this is funny- unless you're one waiting for the mystery parts to arrive in the mail!
Thanks for filling me on on this...