Fender offset bridge options – A tale of three bridges

Suddenly – I appear to have three different Fender offset projects on the workbench. My new, Custom Jaguar USA, my Olympic White “1962” Jag, and also a Kurt Cobain inspired JagStang. The two Jaguars both use the Fender Jaguar/Jazzmaster, floating tremolo system – the JagStang uses a different, “Dynamic Vibrato” system. (Also sometimes known as the Mustang tremolo system). In all cases – a separate bridge is an integral part of the system, and these usually need to have a little, side-to-side, movement – so that tuning issues are kept to a minimum. This is achieved by having the bridge sit on two posts, which themselves sit loosely in two, small, metal cups or “thimbles”

So far, so similar. But things rapidly get more complicated. When it comes down to the specification of the actual bridges on different offset models – there are, nowadays, three main configurations for consideration. The original Fender Jaguar/Jazzmaster bridge and the Fender Mustang bridge, (or one of it’s re-engineered clones, such as the “Staytrem”) cover most of the offset guitars out there. However, for the last decade, or so – there has been a third viable option out there too. The rather less Fender-associated, Tune-o-matic style bridge. (Fender call it an “Adjust-o-matic”). Over the past few months I have acquired an example of each, and now I really need to decide which bridge would better suit each build. I’ve been reading up and researching as much as I can, about each option. The reasons behind their developments, and the pros and cons of each. Of course – sooner or later, online discussion boards come into the equation – and then opinions start to get a little more blurred. Things get confusing. Some people get angry…

And it’s not just a matter of (wild), subjective opinion. There appear to be very real, apparent differences, in the critical dimensions of each system. Indeed – the original ABR-1, Tune-o-matic, (TOM) bridges – having been developed mainly for Gibson guitars – seem to have developed around a completely different architecture. There are some critical, objective measurements here, which may need to be considered.

I already fitted a “Staytrem”, Mustang style bridge to my Olympic White Jaguar project – but that seemed to sit quite high, initially. So much so – that I felt I had to shim the neck to get the action right. Might I be better sticking with the original Jaguar format bridge, on my original build? Also, in researching Kurt Cobain’s designs for the JagStang – he seemingly expressed a clear desire to use a TOM bridge on his first concept drawings. Back in 1993, Fender just didn’t do Tune-o-matics. Perhaps Kurt’s Fenders were being modded to receive Gibson bridges? His famous Jaguar certainly seems to have a TOM fitted. Since then, Fender have made a few inroads to TOM design themselves. But does the Fender TOM conform to the Fender standard? – or the original Gibson standard? Little differences in dimensioning have a critical influence on how easily a custom build comes together.

And since I’ll eventually need to get the body of my JagStang custom made, I’ll need to know exactly which bridge I’m going to use in advance – and then make sure the holes for the thimbles or post bushings are pre-drilled correctly. With Fender and Gibson standards differing by a few millimetres, (at least, that’s what they say on some discussion boards) – I’m going to have to make sure I know what I’m letting myself in for.

It seems to me, that with three different projects – there might actually be a scenario where I can use all three options. A different solution per build. However – which goes where best? With two different Jaguar bodies to try out the bridges on, and with some digital calipers to get some reasonably decent measurements – I can go through each in turn, and see what issues arise. (Measuring accurately is still a little tricky – especially with my ongoing vision problems. But I’m currently test-driving a pair of magnifying spectacles, cooked up by my opthamologist. My digital calipers also have a nice, large, idiot-proof, LED display. My measurements might not be 100% accurate – but they should be within the same sort of tolerance range, for comparison purposes. In other words – these are measurements made by a somewhat, visually handicapped individual – trust them at your own risk).


Fender Jaguar/Jazzmaster bridge (Fender part number 005-4460-000)

Fender Jaguar / Jazzmaster bridge assembly

The Fender Jaguar bridge, essentially takes the same, individually-adjustable string saddles previously developed for the Stratocaster tremolo system, and mounts them on a simple, twin-post plate. The bridge is located on the guitar body – some distance away from the actual tremolo plate. The whole bridge assembly is allowed to gently rock backwards and forwards under friction from the strings, whenever the tremolo is operated. This helps ensure that the tuning of the guitar remains stable. It’s a neat solution – but it does have it’s drawbacks.

Part of the distinctive sound of the Jaguar, (and Jazzmaster), is derived from sympathetic resonances produced by the long string “tails”. The lengths of guitar string running between the bridge contact points and the anchor points on the tremolo plate. Because these string lengths are, in themselves, quite long – the actual break angle where each string passes over the bridge saddles, is quite shallow. This lessens the downward pressure of each string at the bridge – making for a slinky feel, and a highly distinctive sound. However, it can also lead to strings buzzing and rattling – even jumping off the saddles with heavy play. Reputedly – some of the earlier Jaguars might actually have been less prone to this, but nevertheless – many Jaguar players over the years have considered replacing the original bridge at some point. (Probably, immediately after removing that redundant mute).

But the original design does have some clear advantages. Since the height of each saddle can be slightly altered by adjusting a pair of small grub screws – the curve of the bridge can be altered to accommodate both 7.25″ and 9.5″ radius necks. This keeps production costs down. Furthermore, the simple hex-wrench adjustment of just two screws – one within each of the pivot posts, allows the entire assembly to be lowered and raised to suit the particular neck / body alignment conditions precisely. Intonation adjustments are per-string, and achieved by moving the individual saddles backwards and forwards on lateral screws. There’s plenty of scope for fine adjustment, but the downside is that there are plenty of individual, moving parts. Ultimately, the original bridge solution is a bit of a compromise – but it’s all part of that original character.

A quick note on measurements. In all cases, I test fit the bridges in the thimbles already installed on my two Jaguar bodies – to make sure they rock gently backwards and forwards, as they should. In the case of my “62” Jaguar – I can restring the guitar, and try to assess the action. I can also take some critical measurements of each bridge assembly with my calipers. Since it’s difficult to measure the centreline to centreline dimension between the posts, I calculate the span by measuring the outside post to outside post dimension, (A), before subtracting the diameter of just one of the support posts, (B). The “nominal height” dimension is the apparent height of the bridge from a point midway between the foot of each post, to the highest point on the highest saddle, and is measured by holding the bridge posts on a flat surface, and then measuring from there.

o/s post to post measurement (A)79.5mm3.129″3 1/8″
post diameter (B)6.2mm0.244″1/4″
c/l post to post measurement (A-B)73.3mm2.885″2 7/8″
nominal height36.46mm1.436″1 7/16″
Fender Jaguar / Jazzmaster bridge dimensions

The first thing I notice, is that the original style bridge appears to sit lower on the Olympic White “62” Jaguar, and although somewhat unexpected – that certainly seems to make some sense, straight away. (When I’d originally installed a Staytrem bridge on the “62”, I had to shim the neck to get the action anywhere near decent). Perhaps there’s a difference in that nominal height dimension between this and the Staytrem?

Otherwise – the bridge sits perfectly well in the installed thimbles. That shouldn’t be surprising – since this is the default Fender Jaguar and Jazzmaster option for their “vintage” guitar range. (Fender part number 005-4460-000). The Fender specification states the post spacing as 2 7/8″ – so my measurements, and measuring method, both look reasonably accurate. It should be noted additionally, however, that the height of the standard bridge is adjustable, and that the dimension shown is the dimension of the bridge, as supplied – not as fitted to achieve the ideal setup.

“Staytrem” Mustang style bridge

Staytrem” Mustang style bridge assembly

The Fender Mustang bridge is a considerable evolution of the standard bridge, and improves on the original by beefing up each individual string saddle. This allows for deeper string slots on each, with less scope for the strings to buzz or slip out. The saddles are machined from stainless steel, and there are simply fewer parts to achieve the same result. Fewer parts obviously means fewer potential causes of rattle and buzz.

Of course – losing the individual saddle height adjustment screws means that the saddles are all pre-set at a fixed height above the bridge plate, and are also fixed in their configured radius. For the Fender Mustang bridge – that’s usually a fixed 9.5″. However – the Staytrem alternative can be had in both 7.25″ and 9.5″ variants – so it’s also a potential drop-in replacement for Vintage models.

And this example is a 7.25″ radius “Staytrem” bridge. Manufactured in the UK from high quality stainless steel – the Staytrem is an improved version of the Fender Mustang design – differing mainly in the overall quality of construction, as well as the addition of some nylon bushings to the two support posts. (These help smooth the rocking movement a little, and further cut down on potential rattle). When I originally put my “62” Jaguar together, I opted for this Staytrem bridge after hearing about many of the rattling and buzzing problems associated with the original specification. In the event – I had to shim the neck to allow for an apparently taller, nominal height. Let’s see if that bears out in the measurements…

o/s post to post measurement (A)79.5mm3.129″3 1/8″
post diameter (B)6.34mm0.25″1/4″
c/l post to post measurement (A-B)73.16mm2.879″2 7/8″
nominal height36.5mm1.437″1 7/16″
“Staytrem” Mustang style bridge dimensions

So, the dimensions confirm it as a straightforward, “drop-in” replacement – but the nominal height, as measured, appears to be the same. Something isn’t right…

After checking the depths of the thimbles on the two Jaguars – I discover a potential discrepancy. The thimbles fitted on the USA body are, apparently, shallower than the thimbles on my “62”. This isn’t of immediate concern – since the bridge height can usually be modified by adjusting the screws on either post. However, since both bridges actually measure the same, (or thereabouts), it does demonstrate that there may well be to be a significant difference in the neck / body / bridge, positional relationships – between the two Jags. I might have to bring that into consideration when planning which bridge to use where – but since the “Staytrem” is designed as a straightforward, “drop-in” solution – then I think this confirms that there’s something possibly not quite right about the way my “62” Jaguar’s neck sits. Or perhaps I’ve just got hold of some weird thimbles…

The “Staytrem” is manufactured here in the UK, and is an upgrade on the equivalent Fender Mustang style bridge, (Fender parts number 770-9942-000). The Mustang bridge design is a standard modification included on the Fender “Johnny Marr” Jaguar, signature range – and that, in turn, was a heavy influence on my original choice when putting together my “62” Jaguar. A lot of Jaguar players seem to rate the Staytrem as the obvious upgrade on the standard, Fender Mustang bridge. Now that I have the option – I may consider using the Staytrem bridge for my Custom US Jaguar.

Fender “Adjust-o-matic” style bridge (Fender parts number 007-6230-000)

Fender Adjust-o-Matic style bridge assembly

And then there’s the Fender Tune-o-matic bridge, (adjust-o. Whatever…). This bridge originally appeared as part of the Fender “Classic Player” range of guitars. It’s a bit of a wierd fish, all round.

There have always been players who liked the sustain which, they claimed, the Gibson Tune-o-matic provided, above all others. (Equally, there are many other players who wonder, in that case, why the TOM lovers still choose to play Fenders – when there are all those Les Pauls out there). Kurt Cobain was one of the TOM fans, and there’s evidence that he had his iconic Jaguar custom-modded to receive humbucker pickups and a TOM bridge. Both standard, Gibson fare. When Kurt put his sketches together for his JagStang concept – he specified a “Tune-o-matic bridge – or whatever works best”. That was back in 1993. The Fender “Classic Player” range came along much later – and by then, some production Jaguar designs had even evolved to incorporate dual humbuckers and a TOM bridge. There was eventually, a limited run, Kurt Cobain tribute model – which seemed to use this exact bridge.

But the Fender TOM isn’t quite a quick, “drop-in” modification. Or is it? We need to look at the difference in how a TOM bridge is supposed to work.

The Tune-o-matic bridge, and it’s many similar cousins – is a nifty solution which offers stable saddles, individual string intonation adjustment, together with bridge height adjustment via two, threaded support posts. Wheras the traditional Jaguar bridges have to allow for a little movement – some TOM bridges rely on much sturdier support, and get it from two oversized, threaded bushings, into which the two support posts are individualy screwed. Bridge height adjustment can be made, by turning the two, knurled discs – one on each post – under the bridge piece, or by turning the slotted posts from above, with a screwdriver.

It’s a well-proven design which has stood the test of time. But does it really suit a Jaguar? Well, if you’re looking to use the tremolo – then perhaps not. But if you just like the styling and the functionality – why shouldn’t you consider a TOM on a Jaguar?

With the ABR-1 and other, Gibson type variants – it’s all down to those post bushings. They’re not really sized to fit the usual thimble hole dimensions on a Jaguar, and if you want to properly seat a TOM bridge on a Jaguar body – you usually have to plug and re-drill the body to allow for the correct bushings to be installed. That’s not major surgery for some, but you’re not going to do it right unless you know exactly what you’re doing – and a lot of people are going to think twice, especially if it means drilling into your nice, expensive, lacquer finish on your nice, expensive, Fender body. Plus – it’s pretty much a one-way journey, and not one which you can easily un-do.

And then, you can’t really just drop a TOM bridge into the usual Fender Jaguar thimbles. The post-to-post dimensions are similar – but ideally you need the posts, (which are threaded), to tap securely into the bushings – so that the bridge can be properly lowered or raised, whilst remaining totally stable. The usual TOM posts are quite thin, compared to the internal dimensions of the Fender thimbles – (but curiously, the Fender TOM posts seem almost purposely designed to drop into Fender thimbles. What’s going on?)

Is the Fender version merely a stylistic nod to the TOM design? – yet built to allow a certain amount of movement like previous Jaguar bridges? Since I’ve got the opportunity to measure the fender TOM with and without it’s supplied bushings – I can measure, and double-check the critical post-to-post measurement. Since I’m planning to get my JagStang body custom made by Warmoth, and since they offer pre-drilling of the support holes for both Mustang and TOM bridge thimbles – I really need to decide early on, whether I stick with the tried and tested Mustang option – or follow The TOM route, and see if I can bring Cobain’s original intent to life.

o/s post to post measurement (A)85.07mm3.35″3 11/32″
post diameter (B)11.3mm0.445″7/16″
c/l post to post measurement (A-B)73.77mm2.905″2 29/32″
nominal height39.3mm1.547″1 35/64″
Fender Tune-O-Matic style bridge dimensions (with large post bushings)
o/s post to post measurement (A)82.8mm3.26″3 17/64″
post diameter (B)9.0mm0.354″23/64″
c/l post to post measurement (A-B)73.8mm2.905″2 29/32″
nominal height35.5mm1.397″1 25/64″
Fender Tune-O-Matic style bridge dimensions (with T-O-M posts only)
Fender Tune-o-matic posts and bushings, (with traditional “thimble” also shown)

The first thing that strikes me, is that the post-to-post dimension, although slightly different from the other two options, still technically allows the bridge to act as a drop-in option with regular Fender thimbles. However, in such a case, the height adjustment facility isn’t functional, due to the fact that the thimbles are, (annoyingly), ever so slightly larger in diameter, and are unthreaded. To use the Fender TOM on a standard Jaguar body – it looks like the usual thimbles need to be removed, and the holes potentially filled and re-drilled to the correct diameter, to receive the new bushings. However, annoyingly – I can’t find the Fender specifications for these critical dimensions anywhere. This is too critical a job to consider with only “approximate measurements”.

The question is – when Warmoth offers a “TOM” option for bushing drilling – does the spacing match my apparent, measured, dimensions for the Fender TOM – or is it for an ABR-1 type? The dimensions seems strangely close – but things will need to be within a tight tolerance for the bridge to function correctly. Since I’m not really sure what Fender are doing here – I’m left a little confused as to whether I’ll be able to use the Fender bridge, should I eventually opt for the TOM option. The more I look at it – the less it appears that the TOM is supposed to be a drop-in option. It just looks like Fender went off on a different standard entirely.

And yet I think I could actually get it to work – if only I could provide a threaded thimble for the posts to tap against. A simple solution might be to simply thread a nut over the M8 threaded posts and, with some copper tape to act as “padding” between the post threads and the inside of the standard Fender thimbles – the nut, which would sit atop the thimble could be turned to raise and lower the bridge as desired. Admittedly – the practical adjustability wouldn’t be quite as simple a matter as turning a knurled dial, or a slotted screw – but it certainly should work to provide a basic functionality, at least.

Fender TOM – Apparent pre-set radius of 12″

Importantly – if I did experiment in this way – using the standard Fender thimbles instead of the larger bushings would always allow me to revert to a Mustang style bridge at any stage – wheras if I drill for larger bushings – reverting will always be a much more involved process. However, there’s yet another potential problem with the Fender TOM…

As with the Mustang bridge – all TOM bridges have the string radius curve pre-set. The Fender Jaguar and Fender Mustang bridges both conform to the usual Fender “Vintage” and “Classic” fingerboard radii – 7.25″ and 9.5″. Most TOM bridges, (and this Fender example looks to be no different), are pre-configured for a 12″ fingerboard radius. You can still, of course, use them with standard Fender necks – but either the outside strings will sit high, and have a more difficult action – or I’ll need to get busy with a file, and try and deepen the string slots. It’s true that the individual saddles can be replaced and reconfigured, with taller or shorter alternatives, but since I don’t think you can get any taller than the two existing centre saddles, it’s difficult to see how the radius could be physically increased that way. (Perhaps someone needs to work on a conversion set of saddles for the sanity of us poor, detail-obsessives).

Fender TOM bridge vs 7.25 radius curve. Room for adjustment?

Those attempting to file the slots deeper will probably find that adjustment of the string slots is limited due to the need to keep the strings clear of the bridge body plate, itself. There’s very little room to deepen the outside slots since the outside saddles are shorter. I’ve no idea what Kurt Cobain’s solution was – but he supposedly fitted his favourite Jaguar neck profile to his Mustangs, his Jaguar, and, reputedly, his Sonic blue JagStang too. All with TOM bridges? Perhaps he just put up with the stiffer action? Or perhaps that might answer the question as to why Fender, eventually, went with a Mustang style bridge for the limited production run of the JagStang? Was Kurt’s original vision too much of an unplayable mongrel?


Conclusions

Clearly – looking at the whole question of Fender offfset bridges – there’s a lot to consider. Frankly – it’s a bit of a minefield, but I think it’s been a useful exercise in developing plans for my various project builds. Firstly – I think I’ll take the “Staytrem” off my “62” project, and re-assign it, potentially, to the Candy Apple Red, Custom USA build. I’m a fan of the vintage, 7.25″ radius, and plan on using that standard on my ideal build. The upgraded Mustang style bridge is well-loved by many other players, and since I plan to also look at elements of the Johnny Marr Jaguar switching circuit – it makes sense to bring various upgrades together in my Custom specification

It looks like the geometry problems encountered when I used the Staytrem bridge on my “62”, Olympic White build may, perhaps, be down to a simple difference in thimble depth. Since I can adjust the standard Jaguar bridge for overall height, and for individual saddle height, this may give me the range of adjustment necessary to install the bridge without needing a neck shim. This would be a useful exercise in continuing to focus that build towards a strict 1962 stylings. Of course – using a traditional style bridge would look the part – but it would make the “62” a little more prone to the usual buzzing and rattling problems. Maybe that’s the point. Whilst you gain in authenticity, appearance-wise – you also gain a closer architecture to the original – and with it, presumably, a more authentic sound. That’s great – just so long as you’re happy to deal with any inherent weaknesses.

Since I have a spare mute assembly – I might as well install that on the “62” too, and work to complete the period look. If I do encounter buzz and rattle problems, I’ll probably resort to the usual recommended work-arounds. From research – that seems to be a combination of thread-lock compound, PTFE tape, and a device called a “Whizzo Buzz Stop”. It looks like my Olympic White Fender might be about to put on a little extra weight – what with all the new, metallic hardware. But with the authentic wiring and authentic pickups – it’ll be interesting to see if I can fully capture the character of a 1962 Jag, both in terms of look and sound..

So – essentially – the plan is… The two Jags swap bridges – that just leaves me with a Tune-O-matic option for the JagStang. I’d like to investigate Cobain’s original intent, and the idea of being able to use a TOM with the standard thimbles is intriguing. That ability to easily switch back to a Mustang bridge without major modification would mean I could get to experiment with the Mustang Tremolo system on the same setup, (and there’s plenty of idiosyncrasies to explore with that, as it is). If I fudge the Fender TOM, I can still keep my options open. If I pre-drill for an ABR-1, or even the proper Fender TOM post-bushings – it’s a one-way trip, and there’s no going back without a struggle. Especially if that pre-set radius problem can’t be worked around.

It’s one thing to stick dogmatically to the intended design – it’s another to get it all working seamlessly. Maybe that’s why Cobain’s first designs were eventually modified by Fender for final production – in favour of the Mustang bridge. Maybe that’s even why the original JagStang didn’t ever really make it into the recording studio? I think I still need to look into options for my JagStang build, but I must admit – I’d be interested in trying out a TOM, just to build it like Kurt Cobain first envisaged. I’m just not convinced that I wouldn’t be reaching for the wood-filler and re-drilling those bushings a couple of days after “finishing” the build. Once I settle on a neck for the JagStang – I think I’ll be sourcing another “Staytrem” Mustang-style bridge, with the correct radius.

Just in case…

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