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Does anyone happen to have any experience with very light weight bridges? I have some really nice, black Brazilian. I just made a couple of belly like bridges and they came in pretty light. Like 20 and 22 grams before pin holes and top radius. This is the lightest this bridge shape has ever weighed in at by probably 4 or 5 grams. In this case the guitar I was wanting to put it on has a fairly light, stiff Redwood top. 16" lower bout but has an arm bevel so it's loosing an inch of real estate. In comparison, an Ebony bridge in this shape and this state of finish would be about 30 grams. I also made a Pau Ferro at the same time and it weighs 27. The Brazilian seems solid enough. It's just not very resinous. Kinda dry but does polish up nice.

Any thoughts would be appreciated.

Thank, Danny

That sounds right for Brazilian. Most of my Braz or Mrw bridges are under 20 grams.

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Burton
http://www.legeytinstruments.com
Brookline, MA.

Danny: Given you have the right structure, foot print and wood( Brazilian is the right wood) I think its impossible to build too light a bridge. The bridge area is the most sensitive part of the top and any changes there are strongly reflected in the output of the guitar. I like light bridges mainly because of the increase of responsiveness. Other folks like heavier ebony bridges for their damping of certain frequencies and their looks. Depends what you want out..............I guess it's pay your money and take your chances.

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A person who has never made a mistake has never made anything!!!

Thanks! The guitar is for a fairly light attack finger style player. I guess I could always glue a bit of lead to the bridge plate.

Really light bridge is perfect for this application IMO. Low weight bridge = high volume, very responsive. I've made 17-18g bridges on lightly braced, thin topped instruments that made for really explosive sounding guitars.

That's what I was hoping to hear! Thanks James. I usually shoot for lighter weight but this one will be a bit of new ground.

I am a huge fan of Brazilian bridges. Go for it!

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It's not what you don't know that hurts you, it's what you do know that's wrong.

my latest is a size 2 parlor with a 12g EIR bridge. it's a traditional pyramid style and i haven't even put the holes in it yet. i like light bridges.

A light bridge will tend to accentuate the trebles. I had one student who got a bit carried away carving the bridge for her OM, and it ended up at about 22 grams. It was a bit too bright for her taste, and we ended up adding a couple of grams of weight with poster adhesive inside the top. Later, when it got varnished, that reduced the highs enough that we removed the gunk.

Another vote for low mass bridges, in the 14-20grm range. Easy to make heavier (if you want) with denser bridge pins.

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Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au

Thanks all. I look forward to the outcome!

I make all my bridges as close to 30 grams as possible because I tune my tops (and backs) to specific fundamental resonances during construction, and the bridge weight is an important part of the equation. A light bridge will raise the fundamental resonance of the top, resulting in less warmth in the final tone when compared to an identical top with a heavier bridge. You may like the results of using a lighter bridge, this is why I keep detailed records of each build. When I want to make future adjustments, I have hard data to use in making decisions.

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It will probably be alright.

Hi Greg and welcome to OLF. You make all bridges 30ish regardless of playing style? I can see where if one was building dr%*#ds for heavy handed players that might not be such a bad idea. I've been working my way down in weight and have been happy with the results. This will be the lightest for my in a belly like bridge, which is why I asked the question. I've also had great results with 30g bridges. I do find they like to be driven a little harder, and if so the guitar is less likely to over driven if you know what I mean. In this case, the guitar is for a guy with a fairly light touch. "It will probably be alright"

Speaking of bridges, I like the shape you use on the guitar in the other post by you. Nice clean work!

Cheers,
Danny

Thanks for the welcome and the compliment!

I tune and voice my guitars for the individual player using top wood selection and fundamental resonance. When I say top wood selection, I am referring to sonic data rather than species, grains per inch, etc. I test all potential tops using dynamic (tap tone) and static (deflection) tests, the results of which go into a spreadsheet. The software assigns a Q-rating to each test top that is based on modulus (inherent strength), speed of sound, and mass per square inch at final thickness (density). This allows me to select tops that have more headroom for heavy handed players, or more responsive tops for finger style players. The top is then tuned to a specific resonance during the carving process. A lower fundamental will result in more warmth (bass) but at some point the tradeoff is less treble. Its a combination of art and science, and using past data and tonal results to fine tune future builds.

Because I tune the tops to a specific resonance in the mold that will change once the box is glued up, bound, finished, and with bridge weight glued on, I weigh my bridges and use a standard weight to ensure that the completed guitar will end up at the target resonance.

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It will probably be alright.

As with everything else having to do with the guitar, there's a whole range of things that work for somebody. You have to figure out what's going to work for you.

It always seems to me that the main function of the bridge is to tell the string how long it is, so that it will 'know' what pitch to make. In theory the bridge should be 'fixed': massive and rigid, to do this. In practice you would not hear anything if that were the case, since the top would not be moving. Thus the trick is to make the bridge massive and stiff enough to define the string length in practical terms while still allowing for enough movement to be heard. Thus you need to look at the bridge as an element of the top; the heaviest, and one of the stiffest braces on it.

I tend to use 'tapered' bracing; taller and stiffer at the bridge, and lower as you go back toward the edge of the top. With all that stiffness in the center I don't need to worry so much about having enough mass or stiffness in the bridge to provide a good stop for the strings. A Dread with scalloped bracing needs a heavier bridge to make a decent stop. Trevor's 'falcate' bracing provides even more stiffness in the center than my more 'traditional' style, so he can get away with a lighter bridge.

It also helps that Trevor is careful to 'tune' the finished top to that the 'main top' resonant mode is well off any scale pitch, so that's another aspect of the equation.

As Trevor says, it's fairly easy to add mass to the bridge if you need to, but can be hard to take it off. That, in itself, is a good argument for a light bridge, but in some cases, where you know it's not going to work out, there's no reason to push it.