Weird brige

[MartinBorgen]

From a rather new double bass player.

My plywood double bass i bought used has chimsled (sic?) bridge, about 1cm (~1/5th ") of small pieces of wood under the feet, and under that, directly between these peces of wood, there seems to be some kind of thing plastic tape. I guess this is some weird home-brew, and should be replaced? Also, plastic film can be found under the E string and G string, between the strings themselves and the brige. What is this?

Im planning to take it to a luther anywas soon, but i want to make sure of what it is I have here before i go.

[bigolbassguy]

There's nothing normal about what you're describing. I'd love to see a picture... just to be sure

[George700DL]

Originally Posted by psykopatsak

From a rather new double bass player.

My plywood double bass i bought used has chimsled (sic?) bridge, about 1cm (~1/5th ") of small pieces of wood under the feet, and under that, directly between these peces of wood, there seems to be some kind of thing plastic tape. I guess this is some weird home-brew, and should be replaced? Also, plastic film can be found under the E string and G string, between the strings themselves and the brige. What is this?

Im planning to take it to a luther anywas soon, but i want to make sure of what it is I have here before i go.

I wonder if that thing under the bridge feet could be something inspired by Chuck Traeger's book, where he talks about Teflon pads under bridge feet.

The insert between the string and the bridge is something else entirely - perhaps the previous owner wanted to mute those strings a little, or the notches were too deep, or a bunch of other reasons.

[bassics1975]

The wood that you describe under the feet are most likely shims to prop-up the action a bit on a bridge that is too short. I have seen this on several occasions with plywood basses. Rather than a costly bridge replacement, luthiers may often suggest this quick fix if the bridge is otherwise fine. As for the plastic film you describe between the strings and the bridge, this may be a bearing of sorts to allow the string to glide smoothly over the bridge without tilting it when the string tension is brought up.

[MartinBorgen]

bassics, that could make sense, since I figuer a shimmed up bridge would be less stable than one with both feet solidly on the lid.

What puzzles me though is that there is more shims than string height...

[bassics1975]

Under normal circumstances, the shims shouldn't be too thick because of stability etc. The bridge is going to affect the action of the instrument with seasonal changes. Shims were a quick fix for this scenario or in cases where the owner didn't want to invest in a refitted bridge. I have seen situations like yours where excessively thick shims were used. In such cases, the top of the bass had sunk considerably because of a poorly fitted bass bar. How is the integrity of the top on your bass?

As far as the material between the shims that you describe is concerned...is it possible that tape may have been used to hold the shims while the bridge was being adjusted?

[MartinBorgen]

bassics, i think you might be entierly correct about the plastic film. It's stickey, so it probably was probably adhesitive.

The top of my bass is just fine, after all plywood can stand some punishment. The "bass bar" is something i don't know - or is it some kind of reinforcement under the bass side of the bridge? the soundpost seems to be in a normal position form what i gather (that is, not obiously out of place, slightly below the treble bridge side foot -ish).

There are some rather heavy steel strings on now of unknown brand (bronze couloured with black ends), so maybe those are the reason for the shimmed bridge? i plan to have them replace with something that doesent require three fingers do take a low F or G anyways, to let me use proper technique for the entire gig.

EDIT: oh, and i will get a picture up sometime!

[bassics1975]

Your are right...the bass bar is a reinforcement of sorts on the E-side of the bass. It runs along the grain on the underside of the top under the foot of the bridge. If this isn't fit properly or if it becomes detatched, the top will begin to sink under the tension of the strings. You can tell this by looking at the ears of the F-hole on the E-side and see if they are level with the rest of the top.

Your best fix for your shimmed bridge would be to invest in a new one with adjusters. Good luck.

[MartinBorgen]

thank you for your help. The bass is not at home at the momet (a tad heavy to lug around all the time), but i will check up the bass bar and F-hole when i can.