Testing out some American Pro nylon bushings on a Staytrem bridge

[alexpigment]

My new Staytrem bridge was experiencing some 'not-returning-to-center' issues, and while it wasn't a deal-breaker at all, I decided this was a good opportunity to try out the nylon bushings that ship with the American Pro guitars (purchased from Darren Riley's shop). So far, I haven't really noticed any downsides. The bridge still rocks with trem use, albeit with a more limited range. I also tested 4 different bridges to confirm the bushings fit on all of these:

Staytrem (current model, at least)
American Pro (makes sense)
Squier 40th anniversary bridge (should be the same as the CV)
American Vintage (threaded saddles)

I had worried - in fact assumed - that the grippy matte saddles on the Staytrem would lead to some tuning issues when the trem arm was depressed or pulled past the point where the bridge can rock, but I haven't found that to be the case. On the other hand, I have a shallower break angle than a lot of people here prefer - I don't need/want a bridge that sits a centimeter off the body - so maybe it's easier for the strings to glide over the saddles as a result.

Anyway, I figured I'd report my early findings in case it helped someone in the future. I'll update this thread if I notice any issues going forward.

[timtam]

...I have a shallower break angle than a lot of people here prefer - I don't need/want a bridge that sits a centimeter off the body - so maybe it's easier for the strings to glide over the saddles as a result.

10mm would be a very high bridge. One should be able to get a stable bridge with trem use with a bridge height above the pickguard of around half that. What was your string gauge and bridge height when you were having the 'not-returning-to-center' issues with the new Staytrem ? (the two things, alone or in combination, needed to achieve sufficiently high string downforce, and thus high string-saddle friction, for consistent rocking; along with no string-saddle lubrication).

To my mind the Am Pro's nylon 'anti-rocking' bushings address a 'problem' that need not exist. Fender have never explained their logic in adding them to the Am Pro AFAIK (a cynic might suggest they spent too much time reading some people on Facebook offset groups saying 'wrap those bridge posts with tape to stop the bridge rocking' ? ... which is exactly the wrong thing to do).

In terms of the mechanics, anything that impedes free rocking can be thought of as creating a (new) problem and then trying to fix it. When the bridge rocks far enough forward or back with trem use to be impeded by the nylon bushings, the string's grip on the saddles/bridge is broken. The strings' motion over the saddle changes from gripping to sliding. Then when the string reaches the end of its range and starts coming back the other way, it will grip the bridge again and pull it back towards the neutral position. But because the bridge stopped short of how far it would have rocked with free motion, the string will now attempt to carry the bridge too far. But then the post will hit the other side of the bushing wall, which will prevent it from moving back too far, to the wrong neutral starting point. So it ends up back in more or less the neutral position. Problem solved ? Hmmm ... in a roundabout way ... kind of.

I don't recall that we've ever had a user problem with rocking bridge stability here that wasn't solve-able by following the standard steps. If there are 'edge cases' where those principles don't work they seem to be very rare.

[alexpigment]

I'm using 10-46 strings as that's my usual these days. It's an MJT body, so the neck pocket is not angled; I've got a very slight shim in there at the moment. I fully understand that I could increase the break angle and/or go up a gauge to mitigate these problems, but that would change the feel of the setup and I'd rather not do either. To be clear, it wasn't like the bridge was changing position after each trem use; it was just drifting from neutral over time due to tuning, playing, trem use, etc. At some point I would notice and try to re-center it.

As for why Fender started using these bushings, I think it's just because they ship the American Pro JMs with 9s (like their other guitars), and they also don't want to increase the neck pocket angle (and therefore bridge height) to an extreme degree to compensate. It's easy to be cynical about Fender, but I think a person or team was tasked with making the guitar work as well as it can and still be able to ship out with a string gauge that they consider their "standard", and this was their idea.

As mentioned, I haven't noticed any tuning stability issues whatsoever or any change in tremolo range/behavior, so I wanted to report my early findings.

[Larry Mal]

Sometimes I wonder about those plastic sleeves on these guitars. I had a StayTrem for a while, and it used plastic sleeves to persuade the bridge not to move back and forth, and I absolutely hate the bridge moving back and forth.

Some people here like it, but fuck, I spent well over a decade with only an MIJ bridge on my Jazzmaster and that thing slopped around so much in so many various ways that once a Mastery bridge became available I was all over it.

But my point is that the Mastery bridge is metal to metal from the bridge posts to the inserts and I can't help but think that adds to the resonance in some way. And I definitely noticed that the StayTrem did not have that "wild" character that the Masterys introduce.

But I didn't have the StayTrem long. Honestly I don't know how I would feel about the American Pro bridge and if I would ever think to upgrade it.

[alexpigment]

I don't doubt that the Mastery provides more string-to-body resonance due to the sizing of the posts within the thimbles. To me, the appeal of the Mastery is the ability to adjust the height of each individual string. In a perfect world with perfect frets and a perfectly matched radius, it shouldn't matter that a Mustang-style bridge has a fixed radius. However, that's not a realistic world, especially if you don't level, crown, and file your frets regularly (and professionally). That being said, I've never seen a Mastery come up on the used market for a price that seemed good at the time, and I only have two offsets with standard thimbles anyway (the others were originally AOM-equipped but modded to allow standard bridges), so I've never owned one.

As for the American Pro bridge itself, I've owned two of them that have been on various guitars, but they always get relegated to my parts drawer. They just don't feel solid for whatever reason, even if they generally work. I actually prefer the Squier 40th Anniversary aged nickel bridges over the AmPro, and you can find those on the used market for $20-30 bucks fairly regularly (I have 3 of them at the moment). This newer Staytrem was purchased on a whim for my new build; I just happened to see a 9.5" radius model come up online in the US for a reasonable price, so I jumped on it. It's good and very precisely machined, but it's not significantly better in practice than the Squier bridges.

[timtam]

I don't doubt that the Mastery provides more string-to-body resonance due to the sizing of the posts within the thimbles.
....

Since we're now talking about Mastery, and he's one person who is responsible to repeating this stuff ... transfer of string vibrations to the body is not really a "thing" in solid-body guitars. And particularly not a "good" thing. Despite what Mastery says on their website. He may know how to make a nice bridge. But his knowledge of guitar physics is lacking. But that's unfortunately not uncommon in the guitar industry. You don't need to really understand guitar physics to build great guitars, or parts for them.

The role of a guitar bridge on an electric guitar is to reflect string vibrations reaching it back up the strings (to be seen by the pickups). Which all measurements of real guitars have shown is the predominant fate of those string vibrations - bridge admittance measurements, direct measurements of string vibrations, measurements of vibration reflection, measurement of body vibrations, measurement of sustain ... all consistently showing that relatively little vibration energy leaves the strings. See the independent work of Fleischer, Zollner, and Pate.

So guitar bodies "resonate" much less than some players think. They've been hoodwinked by the 'echo chamber' of science-challenged famous players, guitar journalists,and guitar manufacturers. Who wouldn't recognize the Conservation of Energy Law if it fell on their head. If significant string vibration energy were to enter the solid body, it would be lost from the strings. So not seen by the pickups. Which would make sustain very poor. Which it's not. So, luckily, being wrong about how solid-body guitars actually work doesn't actually have any real consequences. Except when other people believe what the echo chamber says about it.

We feel vibrations with our skin mechanoreceptors. Which are very sensitive to a narrow band of vibration frequencies (and pretty much 'deaf' to other frequencies). Which has seemingly lead those people to over-estimate how much solid bodies are vibrating, and that it's somehow a good thing, viz. "the body really resonates dude". It's nonsense.

[Larry Mal]

I don't doubt that the Mastery provides more string-to-body resonance due to the sizing of the posts within the thimbles.
....

Since we're now talking about Mastery, and he's one person who is responsible to repeating this stuff ... transfer of string vibrations to the body is not really a "thing" in solid-body guitars.

I guess I'm not saying that the body resonates, but it seems like the plastic sleeves around the post would certainly have a deadening effect on the bridge and how the bridge interacts with the strings. Maybe not dissimilar to if you put a violin mute on the bridge.

I'm not going to be able to back any of this up with science, though, so make of that what you will. But I'll freely concede that the pluck of a string isn't resonating a five pound slab of wood covered in plastic finish.

[alexpigment]

[See above]

While I totally get what you're *trying* to say, I think you're downplaying (to a fault) the role of the acoustic properties of an electric guitar. Some of these are audible, some are physical, others are more in the "vibe" category.

Firstly, when you hit an E chord on a guitar, and you can 'feel' the overtones, that makes the guitar seem like a more lively experience. Just like when you go to a movie, and your ears can't hear the tones below ~20k, it is still impactful nonetheless. The notes that jump out will vary from guitar to guitar, and I know which of my guitars resonate with certain notes or chords. I presume you've been playing long enough to know which chords vibrate better on each of your guitars as well.

Secondly, when you play an electric guitar, unless you are playing at deafening volumes or are using in-ears that seal you off from the world around you, you are *always* hearing the guitar acoustically in combination with what's coming out of the amp. This is not a wild or unscientific claim - that's just how it works and it's easy to confirm (and I'm sure you are aware of this as well). When you play a guitar where the neck, body, and other elements of the guitar resonate loudly, it's an additive experience to the electric sound. If a guitar sounds more "lively" than another with the same components, that's the wood talking.

Lastly, the way a guitar vibrates determines how you interact with it. You may find yourself gravitating toward certain notes or chords, or you may find that one guitar works better for lead than rhythm. There's a "vibe" a guitar gives - which may have nothing to do with the pickups or electronics - and it's silly to write this off as a fault in the mind of the player (including professional players that are well-respected and frankly better at guitar than you or I).

Once we get into mic'd land or YouTube demo land, all of those factors sort of go away, and you can rely on strict science about how vibrations are picked up by pickups, but that's not how any of us - including yourself - interacts with or experiences a guitar. I know you're trying to make a scientific point that is based in reality, but none of us have been "hoodwinked" and this isn't nonsense. I am not sure how you've let some facts within a vacuum and without context override your basic experiences as a guitarist.

[alexpigment]

Also, I suppose it's worth mentioning that I respect all your contributions here on the forum, and I don't mean any ill will, nor am I trying to start an argument. I just find this to be a particularly contrarian-for-no-reason post from you, which seems out of character to me from your usual posts.

[andy_tchp]

To me, the appeal of the Mastery is the ability to adjust the height of each individual string.

Individual string height adjustment is impossible with a Mastery bridge.

Each saddle carries three strings, with action adjusted by a fastener at opposing ends of the saddle. The saddles themselves are subtly radiused so the bridge can be adjusted to the more commonly required/desired radii.

[alexpigment]

To me, the appeal of the Mastery is the ability to adjust the height of each individual string.

Individual string height adjustment is impossible with a Mastery bridge.

Each saddle carries three strings, with action adjusted by a fastener at opposing ends of the saddle. The saddles themselves are subtly radiused so the bridge can be adjusted to the more commonly required/desired radii.

Yes, I totally misspoke there - thanks for clearing that up. I just meant that you can raise the saddles to deviate from the radius. If you need to raise the B or A specifically, you can’t really do that. I think the more common problem on a mustang style is needing to raise the high E without raising the G (and B to a lesser degree) string. The high E is a very delicate balance in terms of having comfortable action and not fretting out in my experience.

[timtam]

[See above]

While I totally get what you're *trying* to say, I think you're downplaying (to a fault) the role of the acoustic properties of an electric guitar. Some of these are audible, some are physical, others are more in the "vibe" category.

Firstly, when you hit an E chord on a guitar, and you can 'feel' the overtones, that makes the guitar seem like a more lively experience. Just like when you go to a movie, and your ears can't hear the tones below ~20k, it is still impactful nonetheless. The notes that jump out will vary from guitar to guitar, and I know which of my guitars resonate with certain notes or chords. I presume you've been playing long enough to know which chords vibrate better on each of your guitars as well.

Secondly, when you play an electric guitar, unless you are playing at deafening volumes or are using in-ears that seal you off from the world around you, you are *always* hearing the guitar acoustically in combination with what's coming out of the amp. This is not a wild or unscientific claim - that's just how it works and it's easy to confirm (and I'm sure you are aware of this as well). When you play a guitar where the neck, body, and other elements of the guitar resonate loudly, it's an additive experience to the electric sound. If a guitar sounds more "lively" than another with the same components, that's the wood talking.

Lastly, the way a guitar vibrates determines how you interact with it. You may find yourself gravitating toward certain notes or chords, or you may find that one guitar works better for lead than rhythm. There's a "vibe" a guitar gives - which may have nothing to do with the pickups or electronics - and it's silly to write this off as a fault in the mind of the player (including professional players that are well-respected and frankly better at guitar than you or I).

Once we get into mic'd land or YouTube demo land, all of those factors sort of go away, and you can rely on strict science about how vibrations are picked up by pickups, but that's not how any of us - including yourself - interacts with or experiences a guitar. I know you're trying to make a scientific point that is based in reality, but none of us have been "hoodwinked" and this isn't nonsense. I am not sure how you've let some facts within a vacuum and without context override your basic experiences as a guitarist.

TL;DR: Everything you say about the acoustic sound is basically true. It's just not due to the body vibrating. Your experiences are entirely explained by the actual measured physics of real guitars. And a bit of neuroscience.

A closely connected misapprehension to "transfer of string vibrations to the body as a 'good' thing" is the misapprehension that the acoustic sound of a solid-body guitar is (1) due to the body vibrating and (2) very closely related to the amplified sound.

Re (1), what you hear when you strum a solid-body guitar acoustically is mainly the acoustic sound waves direct from the strings (that's why it sounds so anaemic compared to a real acoustic guitar). It's not the body vibrating. Those direct acoustic sound waves are what makes the sound of a truly acoustically "resonant" solid-body guitar. That's what you're hearing and responding to. That people connect that to the body vibrating (more) is simply an understandable misinterpretation of their heard experience. No one is saying that "resonant" guitars don't exist. Those are the guitars where vibrations remain almost entirely in the strings (to be seen by the pickups) - that's what you're hearing acoustically.

What you're feeling through your skin from those guitars is subject to the sensitivity but very limited bandwidth of your skin mechanoreceptors. And then what your brain chooses to overlay on that limited 'data'. You feel the frequencies in the band around 300 Hz to which they are sensitive. And you're not really feeling any other frequencies that various parts of the guitar might actually be vibrating at. Think about if you could only hear frequencies around 300 Hz - because that's the analogous limitation of those skin sensors. So while you may draw inferences that there is somehow a correlation between the acoustically resonant guitar (operating according to the above physics) and what you feel, such correlations are fraught. And not only by the fundamental limitations of those skin sensors, but also the bias induced by the 'echo chamber' telling you that solid body vibrations are a 'good' thing. Plus the lack of understanding of the Conservation of Energy Law. Because that, along with the known actual measured physics of real guitars, shows that a body vibrating more must mean the strings vibrating less - so the exact opposite of a truly resonant guitar.

So I don't think it's unreasonable to suggest that some players are kidding themselves as to what they feel and where it comes from. What they hear is a more accurate reflection of the actual sound waves reaching their ears (Fletcher Munson curves and age- or volume-related hearing loss notwithstanding). But their overall experience is significantly subjective, and sensed through a prism of sounds, feelings, and physics inferences that are not all objectively accurate.

The acoustic sound of the strings' vibration is however somewhat important to how an electric guitar functions - because it's the same "signal" that the pickups see. It's reduced by anything that drains vibrations from the strings. That's one thing that Paul Reed Smith is actually right about - guitars are "subtractive" (on other matters, like 'tonewood', he has the typically-vague bundle of misunderstandings of guitar physics common amongst guitar builders). The measurements of real guitars I mentioned have shown where those small losses commonly occur - to the long, thin, flexible, composite neck (at its resonant modal frequencies), and to excite internal bridge vibrations. And in trem-equipped guitars like strats and offsets, some vibrations pass over the bridge to the residual string length behind the bridge, vibrating both that extra string length and the trem itself, and mostly never return to the main speaking length of the string. Particular bridges with many moving parts/air gaps have been shown to vibrate more, thus absorb string vibrations internally. The bridge most commonly studied is the ABR-1 of Les Pauls, and it has been shown to be particularly prone to such losses (see ch7 of Zollner's "Physics of the Electric Guitar"). Offset bridges have not been studied in that way, but it is reasonable to assume that they 'suffer' from similar losses.

Of course in all these discussions, there is no implication of what sounds "good" or "bad" to your ears. It is perfectly reasonable that you might subjectively prefer the sound of a guitar with more losses over one with fewer (and possibly misinterpret the underlying physics of why that is).

Re (2), the correlation assumed by some people between the acoustic and the amplified sound, that depends a lot on the pickup. While the acoustic sound is reflective of string vibrations, the pickup does not necessarily reproduce those vibrations with exact fidelity. No pickup sees anything much beyond 5 kHz (and many see a lot less). Guitar amp speakers are similarly limited. There are much higher frequencies present in the strings than any pickup can transduce through to the output (you can however hear some of that upper end acoustically, direct from the strings). A single coil typically has a higher resonant frequency (with an associated low pass cutoff frequency a little above that) than a humbucker. So the SC will reproduce more of those string frequencies in the strings. A pickup also has a Q factor, which tends to emphasize the (treble) frequencies around the resonant frequency.

So in summary, there is never a 1:1 relationship between string vibrations and pickup output. An acoustically resonant solid-body guitar may not seem as "resonant" when amplified, depending on the pickup (and the downstream signal chain).

[timtam]

Also, I suppose it's worth mentioning that I respect all your contributions here on the forum, and I don't mean any ill will, nor am I trying to start an argument. I just find this to be a particularly contrarian-for-no-reason post from you, which seems out of character to me from your usual posts.

It's sometimes hard to convey intent in internet posts (I try to use emojis, but not always well). I'm definitely not trying to pick an argument. I respect your willingness to engage. These are interesting issues to discuss. Fender's not going to discuss the supposed merits of the Am Pro's nylon bushings, so we have to. Apologies if I got too strident.

And the whole "transfer of vibrations to the body" thing just offends my scientific sensibilities. When vendors like Mastery promulgate it, I just have to call them out.

[RockStarNick]

Interesting convo here re: solid bodies, responance, transferring vibes from strings through bridge etc.

Chiming with my experience:

Overall: bridges, bodies, vibrations
- Each guitar body can resonate very differently. Since they're made of trees
- I've found that body weight correlates to density and mass, which in turn, correlate to vibration properties
- I think the each type of guitar (strat, tele, jag) has a sweet spot of body weight + bridge type, that just work best

[RockStarNick]

Taking Teles for an example: Here's my findings throughout the years
- Lightweight bridges on heavy bodies: undesirable, thin
- Heavier bridges on heavy bodies: decent
- Lightweight bridges on lighter/medium bodies: optimal, loud, resonant
- Heavier bridges on light bodies: sounded good, but kinda masked any of the acoustic-like character from the lighter body itself.