Bridge Tips Forward on String Change

[John Flynn]

Whenever I change strings on my Rigel A+ Deluxe, I wind up with the bridge saddle tipping forward about 5 or 10 degrees or so and I have to wrestle it back upright. It tips more on the treble side than the bass. I had this problem with former mandolin also. I change one string at at time and I have tried lubing the bridge string slots with powdered graphite. I use the type and gauge of strings (J74) that came on the mando from the factory. My questions are:
> Is this common, or is it a symptom of a problem with the bridge?
> Could I accidentally break the saddle wrestling it upright? Is there a right/worng way to do that under string tension?
> Is there a way to prevent it?
> Could this be damaging the screw posts on the bridge?

[AlanN]

I hope some experts chime in here, but it's the bane of the design, I think, with a 2-piece, adjustable bridge. It's a pain, it happens a lot, and I hate it, but that's the deal. I checked out Bobby Clark's Triggs F-5 and he had that going on, too. I deal with it when the intonation goes, and it eventually does.

[Hans]

That is a problem with mandolin bridges. Usually happens more on the bass strings because they are wound. When changing strings, change one at a time. If it still tips, tune part way up and pull the saddle back. Tune it the rest of the way and check again.

Hans.

[Scotti Adams]

..its just one of those things that happens...you have to learn to look for it and do the adjustment when needed or as Mr. Brentrup suggested...

[Dfyngravity]

That is very interesting to me because I have never had this problem with any mando I have had. When changing my strings I loosen up all the strings and then one by one I change the strings starting with the outer G string then the outer E string and I work my way to the center which would be the inner D and inner A strings. This method seems to work for me very well.

[Scotti Adams]

...seems to make sense....I assume we are talking about a 2 piece Loar style adjustable bridge...and the top part leaning towards the headstock a little.....by keeping even tension from the ends of the bridge inward that would seem to stop the leaning problem....maybe I will try it sometime...its not an issue with me cuz I just make the minor tweek when needed.

[Michael Lewis]

The "problem" is that the strings stretch as they are tuned to pitch, and they exert a great deal of friction on the contact areas, which tends to pull the saddle toward the fingerbaord. This happens to all floating bridge designs (violin, cello, bass, archtop guitar, banjo, etc.) and is a part of the process. You really do need to keep an eye on the angle or it can cause deformation of the bridge if it gets too severe.

[Fretbear]

The more precision made the bridge is, the less this problem will arise. If the adjustment screw post holes are drilled a bit oversize there is more room for the saddle to tilt forward even though the base has not moved. I always lock my finger at the front of the saddle as I tune up a new string to relieve that forward pulling tension mentioned in the previous post.

[Salty Dog]

I had this problem initially with my BRW. #With my infinite wisdom (right!!!), I decided that (as stated above) the top part of the bridge was tipsy as there was just a bit too much screw post metal showing and the hole for the screw post was not snug. #I had my luthier build up bottom of the top part of that bridge so that at my lowest action setting there would be no screw post showing, only the wheels. #It almost loooks like a solid bridge except for a small gap (1/64"?) between the top and the part fitted to the mandolin top. #End of the problem with no detriment to tone, possibly an improvement.

[Michael Lewis]

Fretbear, even the best made bridges will tip forward if not attended to, unless you can make the notches nearly friction free. I would expect there are exceptions to this rule too, but in my experience bridges tend to tip toward the neck when the strings are tightened.