Easiest/safest procedure for adjusting bridge tilt?

[marcja]

After a couple years, the bridge on my Gibson F5 is starting to tilt toward the nut. As I understand it, this is very common and the standard result of regular tuning and changing strings over a long while. It's extremely minor at this point -- for example, you can't yet slide a piece of paper under the corner of the bridge -- but you can definitely see that the tailpiece-side edge of the bridge isn't making as much contact with the soundboard as the nut-side.

What's the easiest/safest way to reset the bridge to be flat-footed on the soundboard? Loosening all the strings to be completely slack seems like an obviously a bad idea, but I don't want to force the bridge under too much tension either. I could futz with it and figure it out, but I was hoping that there is some standard best practice that people have.

Thanks!
Marc

[John Kelly]

You can ease off the strings slightly and tilt the bridge back again to the vertical, applying equal pressure to it across its width, making sure that you are aware of where the bridge was positioned before you try to straighten it up. This is a regular adjustment for fiddle players, whose bridges are narrower and taller than a mando bridge, so less stable. I often reset the bridge on the instruments of local fiddlers and always advise them to lubricate the bridge slots in the bridge with a soft pencil, so that the strings slide over the bridge rather than gripping on it and pulling it towards the nut.
With your mandolin, it can be a big help to lubricate the bridge slots too, using pencil graphite (or proprietary products). Loosen off the strings a pair at a time, lubricate, then retune to pitch. Pencil lead in the nut slots is useful as well and can ensure that the strings slide through the slots rather than snagging in them.

[sblock]

Well, the safest procedure is, indeed, to loosen all the strings until they are nearly slack, then right the bridge and its saddle, and re-tension the strings back into proper pitch. You can easily mark the bridge position with a bit of masking tape before doing so, if you like. But you can also use this same opportunity to double-check for the proper bridge position (with respect to length, that is: look for a match between the 1/2-length harmonic and the fretted note at the 12th fret), and also for the action height. These things also can benefit from periodic re-adjustment.

If you do not want to, or do not need to, move the bridge position or adjust the action, then you can loosen the strings much less, so that they still retain a certain amount of tension, and right the bridge and saddle under reduced tension. Loosen them at least several whole tones' worth, or even more. This procedure is still pretty darned safe, however, although a bit less so.

If you are confident, experienced, or if you just like to live a bit more dangerously, it is entirely possible to "burp" the bridge back into a proper vertical orientation without removing any of the string tension at all. This is the least safe alternative, however, and I'd tend to advise against it if you lack prior experience and have never seen it done. It takes a bit of force applied to the right places on the bridge (and you must not overdo it!), and the resulting movements tend to be jerkier. Screw up, and you might chip the slots in the bridge, smash (collapse) the bridge down onto the top (possibly denting it),or break a string. But hey, a lot of folks do it all the time!!

[barry]

Well, the safest procedure is, indeed, to loosen all the strings until they are nearly slack, then right the bridge and its saddle, and re-tension the strings back into proper pitch. You can easily mark the bridge position with a bit of masking tape before doing so, if you like. But you can also use this same opportunity to double-check for the proper bridge position (with respect to length, that is: look for a match between the 1/2-length harmonic and the fretted note at the 12th fret), and also for the action height. These things also can benefit from periodic re-adjustment.

If you do not want to, or do not need to, move the bridge position or adjust the action, then you can loosen the strings much less, so that they still retain a certain amount of tension, and right the bridge and saddle under reduced tension. Loosen them at least several whole tones' worth, or even more. This procedure is still pretty darned safe, however, although a bit less so.

If you are confident, experienced, or if you just like to live a bit more dangerously, it is entirely possible to "burp" the bridge back into a proper vertical orientation without removing any of the string tension at all. This is the least safe alternative, however, and I'd tend to advise against it if you lack prior experience and have never seen it done. It takes a bit of force applied to the right places on the bridge (and you must not overdo it!), and the resulting movements tend to be jerkier. Screw up, and you might chip the slots in the bridge, smash (collapse) the bridge down onto the top (possibly denting it),or break a string. But hey, a lot of folks do it all the time!!

I saw Mike Compton do this on a mandolin a guy handed to him to check out before a concert once. The owner handed it to Mike to play and give an opinion on. Mike played it for 15 seconds, looked it over, and said, "the bridge is leaning, want me to fix that?" The owner granted permission, and than.....Skarrrronck!!!! It was done under full tension. All done. No ill effects. Gave me the heebie jeebies though.

[pops1]

I saw Mike Compton do this on a mandolin a guy handed to him to check out before a concert once. The owner handed it to Mike to play and give an opinion on. Mike played it for 15 seconds, looked it over, and said, "the bridge is leaning, want me to fix that?" The owner granted permission, and than.....Skarrrronck!!!! It was done under full tension. All done. No ill effects. Gave me the heebie jeebies though.

I do it that way all the time. Only been playing 40 or so years, no problems yet.

[bennyb]

I don't really understand the reluctance to loosen the strings some and do it that way. Nothing bad will happen. If you tune them down a full step, or a step and a half, it'll be relatively easy and not stressful. Alternatively you could just wait until you next change strings, and monitor the bridge set as you're doing it.

benny

[marcja]

Thanks for all the advice. The only reason that I thought going completely slack on all strings before adjusting the bridge seemed like a bad idea is that it could increase the probability that I move the bridge position and mess up the intonation.

[Tom Haywood]

One of the biggest problems with loosening the strings all the way is that the bridge can begin to lean again as you tighten them, so that you have to adjust it as you tighten. That's actually the normal process when re-stringing. Loosening just enough to adjust the bridge may prevent some of that. I make the final adjustment under full tension, but I've watched several folks without experience crack their bridge.

[Doug Goodhill]

If the bridge is tilted forward the intonation must be off, unless the base of the bridge moved (that wold be weird). It is important to confidently maintain your instrument and removal and re-installation of the bridge should be a goal.