Anyone have experience with, knowledge of, adjustable bridges for banjos,
like we see on archtop guitars and mandolin s ?
I'm sure the reason it hasn't been explored seriously is because they would weigh too much.
quote:
Originally posted by Ken LeVanI'm sure the reason it hasn't been explored seriously is because they would weigh too much.
What Ken said!
Additionally, the characteristics of vibration transfer from strings to banjo head, as opposed to strings to wood could probably be an additional factor that might not support the use of an adjustable bridge.
In the history of banjo building and modification there has to have been more than one attempt to graft an adjustable bridge to banjo. That fact that it is not common practice speaks volumes.
In his book on building archtop guitars Bob Benedetto says that a solid wood non-adjustable bridge sounds noticeably better on an archtop guitar, but that few players are willing to sacrifice the convenience of adjustment to which they have become accustomed. I think that an adjustable bridge for a banjo would be about the same as using a mute that goes on the bridge in terms of the effect it would have on the sound, but I don't know.
We're all picturing a traditional guitar/mandolin bridge with large flat base and metal screws and nuts extending up to the large saddle assembly. Part of the benefit of an adjustable bridge for these instruments is that the base has to be precisely fitted to the top. Can't just swap out one bridge for another without some work.
Banjo bridge is small and light, all wood, usually with 3 legs. They are interchangeable on instruments.
Now suppose each of those 3 legs were cut off about 1/4" from the bottom and a small wooden bolt were grafted onto the lower part with a threaded hole to accept the bolt at the upper part. Each leg can be screwed in or out to adjust the height of the bridge. Total adjustment range needs to be only about 1/16", because beyond that you just get a different sized bridge.
I can't see the weight being any more than a solid bridge, because if the bridge is adjusted up, there is actually less mass than a solid bridge of the same height. There are no metal parts.
The reason we don't see these types of inventions is that it is a very simple matter to adjust the height of a bridge a small amount -- cut the notches a bit deeper or sand a little off the bottom of the legs. (If need more range of adjustment, then get a different sized bridge -- don't have to modify it to fit the head.) A simple solution eliminates the need for a more complicated assembly.
Every banjo bridge I've ever used is adjustable. They float on the head so you can move them around. You can change the height with a file or piece of sandpaper.
I always dreamed of an adjustable bridge like found on electric guitars,but very quickly discovered the mass of that kind of adjustment destroyed the tone and power of a banjo.
I then decided to carve an "adjustment" into a solid bridge which zeroes intonation at the 12th fret.I talked to luthiers about figuring perfect intonation at the 12th fret and they agreed that was the right place to set it for best compensation with no adjustments.
The best weight for a responsive banjo bridge is between 2 and 3 grams.I find the best weight for all considerations to be 2.2 to 2.4 gram with 99% of my orders right at 2.2 to 2.3 grams for bluegrass and melodic performance.Adding screws and stuff adds to the weight.
An adjustable bridge that weighs 2.2 grams would be great,but that isn't possible except maybe if built from carbon fiber.That would cost a lot.
Edited by - steve davis on 01/27/2023 09:06:33
Question for the O.P:
Are you speaking of adjustable for height, adjustable for intonation, adjustable for weight, or some other adjustment. If it's height, solutions have been offered (taller/shorter bridge, cutting slots deeper or sanding the feet. If precise intonation is desired for all strings, there are compensated bridges, which can also be raised or lowered just like plain ones.
Hi Greg
I can see a two piece X bridge with a pivot in the middle
Two solid outside feet with a split middle foot
As noted it doesn’t need to adjust much
The bridge goes straight up and down
With little notches for braces on the arms
Adjustable while tuned up
And it weighs 2.2 grams from bamboo last night in my dreams
Print one?
I have no experience yet
Bridges are floating and held by string tension.
Therefore a bridge in theory could be slotted at the top to slip an ebony top in.
You could have 2 different slot depths and you just flip the ebony or have an oval rotating ebony top?
Just thinking out loud??
I like that, Leon, Nice to hear from you.
This discussion brings up a question and I hope it is not too off topic. I have noticed that some Grover bridges have these little plastic (or possibly other material) inserts along the top of the bridge. What are they supposed to do and what is their purpose?
Robert
I was waiting for others.
We bought that Grover bridge in the '60's because it was the best looking bridge. At the time.
The white pieces on every string is someone's idea. I'm not sure you could prove the advantage.
quote:
Originally posted by TN TimeThis discussion brings up a question and I hope it is not too off topic. I have noticed that some Grover bridges have these little plastic (or possibly other material) inserts along the top of the bridge. What are they supposed to do and what is their purpose?
Robert
I'm no expert, but I've read (or been told) that it is bone. I guess it was supposed to improve the performance and sound of the bridge.
quote:
Originally posted by BNJOMAKRquote:
Originally posted by TN TimeThis discussion brings up a question and I hope it is not too off topic. I have noticed that some Grover bridges have these little plastic (or possibly other material) inserts along the top of the bridge. What are they supposed to do and what is their purpose?
RobertI'm no expert, but I've read (or been told) that it is bone. I guess it was supposed to improve the performance and sound of the bridge.
Nope, this stuff actually is totally genuine imitation-bone. It's purpose? Hmmm, the "awesome looks" of it, no doubt. I've seen a bunch of them over the years and each one of them showed a fair bit bit of daylight between the "pearl" and the ebony it was "positioned into."
