Quote:
Originally Posted by PTC Bernie
Actually, if you look at the load across the cross section of the bridge, the difference in the moment between a pinned bridge and a pinless bridge aren't as different as you might think. The major component is the one pulling the whole assembly in the direction of the head, as you would expect.
The amount of energy that translates "upward" against the underside of the soundboard is small compared to the pull toward the head of the guitar.
My Breedlove SJ25W has a pinless bridge. To my way of looking at it a pinless bridge yields better transfer of energy to the soundboard. The less you have poking through the soundboard the cleaner the sound.
As far as "dinging" the top is concerned, I shaped a piece of cardboard to fit flush against the bridge so that the ball end of the string impacts cardboard, not the guitar surface. End of problem.
All of this is just my less than humble opinion of course.
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The moment is purely dependent upon the angle that the string makes as it leaves the back of a saddle. It has nothing to do with whether it is pinned or pinless. So, two similar guitars, one with pins, one with a pinless bridge -
and with the same string break angle - will have the same 'composite' upwards and forwards moment (force, whatever you want to call it) acting upon it. The difference is.. with a pinned bridge a lot of the force will be acting upon the underside of the bridge plate, whereas with a pinless bridge the force will be trying (more so than pinned) to pull the bridge from the top of the guitar. It's the
anchorage points that make the difference; the moment of the string could well be exactly the same on either style of bridge. Saying that, the break angle is often greater on a pinned guitar, although modern luthiers have taken cognisance of this issue (Lowden, McIlroy) as opposed to the older styled pinless guitars such as Harmony, that were quite flat.