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Does anyone have a target weight they shoot for with a bridge? If so what's your theory?

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I build classicals but my bridges weigh between 14-19 grams on average. Depending on the tonal goals of the client and the fan system/top thicknessing I'll select lighter or heavier bridge material; a lightly strutted, thin top will typically have a bridge between 14 and 16 grams while a thicker top with more robust strutting I'll typically have a heavier bridge. I have no scientific evidence for why I do what I do, more just having seen what works for me after 50 or so guitars, ymmv

For the steel strings I build I like them to be around 22-26 grams. Like Brian I have no evidence, just what I do.

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Steve Smith
"Music is what feelings sound like"

The bridge is part of a system that includes the saddle(s), pins and if we are speaking of the mass on the sweet spot of the top this also includes the bridge patch top thickness and the bridge plate. My view is that all of these things work in concert... or not.... to efficiently transmit vibration to the box to move air. With this said you could weigh each element and determine a percentage for each component that each specific component comprises in the "stack."

Or, in other words I don't think that any one thing in the stack such as just the bridge is as consequential as some may think.

In the repair business we replace bridges all of the time. This means making a new bridge from scratch. For vintage stuff we carefully select a nice piece of maybe BRW if that is what we are replacing and make a nice, new bridge. No one is weighing the old bridge and making any effort to match the mass of the original material in the new bridge beyond using the same material/species.

In nearly 20 years of replacing bridges including on some pretty valuable stuff such as pre-war Martins and vintage Gibsons and for some very discriminating owners never once has anyone ever suggested that a change in the bridge including it's mass resulted in a change in the tone of the instrument. Some anecdotal information for you.

Or, in other words I don't think that bridge mass is as important as I once thought it must be. It's important, it all is but my view is shifting over time to much more consideration for the instrument as a whole and as a system and how it performs.

There is also the issue of the individual box and what it takes to drive it at an optimum level. Pins are always a good example of what I am getting at here people ask about tonal differences in changing pin materials such as bone, brass, ebony, etc. We are pretty sure it's not the material that makes any discernible difference (if there is one...) but we are pretty sure it's the change in mass over the sweet spot of the top that may... may make any resulting difference. Along with this is the fact that some guitars perform better driven harder and vice versa..... Lots of variables.

And lastly tradition such as the Martin style of building a guitar has resulted in some pretty good instruments and no one ever weighed anything for most of them.

Luck is in play too, always.

So not a good answer from me, nothing definitive and that is my point the amount of mass that may be optimal for the components that make up the bridge stack on the sweet spot of the instrument is going to be as individual as how that box is built, out of what, volume of air that can be moved and even the human hitting the thing.

We all have something, some number that we think may work for us and I do and did too but I question this number when I consider the ultimate function of the bridge in a "system" approach to the instrument. My number is also all I know and I certainly don't know the half of it if that and another number may be better for another situation/instrument.

What a number is good for is as a control for the bridge viewed as a variable when analyzing what one has in comparison to another example/instrument.

With this said I think a range.... of numbers for bridge weight is much more acceptable than I once would have thought. You can compensate for the overall amount of mass on the sweet spot of the top with plate thickness, saddle thickness and height (slot depth, etc.) pin material and bridge material and even top thickness in that area for those interested in fine tuning.

Complicated I know or just make a Martin belly bridge or pyramid bridge and slap that puppy on there and call it good.

I don’t have a target weight, but I use the same size bridge and same bridge material on nearly every guitar, so the bandwidth between one end of the scale and the other will be fairly narrow. I do accommodate for the actuality of what any given bridge actually is…

I don't weigh bridges and just make what seems to work but I'm no pro.

I'm in the camp of Trevor Gore on bridge weight.
For Trevor's discussion on bridge weight, see the section titled "Bridge Wood" in the attached paper. I want to fully understand the reasoning but I'm not quite there, and don't yet have the chops to validate a bit of it.

https://aipp.silverchair-cdn.com/aipp/c ... online.pdf

Trevor presents some wood alternatives in the paper, "that rate well balancing stiffness, density and hardness". Two of the three do not necessarily score well in the width/ thickness (T and R) stability found in the Wood Database, when compared to Ebony/ African Blackwood, which raises a further question for me, in terms of dimensional stability of the wood species selected.

These bridge weight and species questions have detracted from building, and I sometimes wonder if I wouldn't be better off just slappin a bridge on it. The bridge blanks I have, and have measured, vary in mass by 100%! The Martin-Clone bridge I made for my current build weighs in at 45 grams, the heaviest bridge I've ever held in my hand. That's what got me reading up on the subject to begin with.

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Measure Twice,

Karl Borum

Picking a target weight for a bridge, especially a "signature" bridge, ends up limiting wood choices as T Gore suggests or the bridge design. My last 3 guitars all had different wood for bridges and even though the same design the weights were all over the place. Padauk was in the mid 20's in grams, macassar ebony mid 30's and gaboon ebony over 40g.

I usually like to match bridge, fingerboard and headplate woods when I can so I almost ignore weight. There is only so much wood you can remove in a bridge.

The two guitars with the largest spread both sound good. I was worried about the ebony bridge being heavy but the most critical customer I have tone wise loves it. As does the owner of the one with the lightest bridge.

I really think there is a lot more flexibility in guitar design than some folks make out.

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Brian R, Wood Mechanic
N8ZED

You don't say if you're building a steel-string or a nylon-string guitar. However, in Trevor Gore's book, he says that a typical wood bridge for a steel-string guitar would be about 35 g. At the high end, they might be 60 g. His bridges are 15-20 g. He says, "we find that a 50 gram bridge will almost certainly condemn a guitar to acoustical mediocrity, whatever else it might have going for it."

For nylon-string guitars, 10 g would be the sensible lowest. His are 10 to 15.

The minimal area would be 45 cm^2 for a steel-string, and 40 cm^2 for a nylon-string.

Greg

True, but it's a lot more than most people remove. Only the front wall of the saddle slot needs to be full height. You can taper the thickness down to nothing at the back edge and it will still function just fine. Maybe better, since a flexible back edge will reduce stress concentration on the glue line.

I generally try to keep below 30 grams, but I haven't built enough to develop any strong opinion of what the weight should be.