When you’ve been professionally repairing and setting up stringed instruments for awhile, you start growing a list of things that irritate you.
Other techs borrowing your tools and not returning them is on the list. (Looking at you, Liam!) But much higher is people who think they must angle their saddles to match their fretboard radius!
In the image above, you can see the two outer saddles of this bass have been angled to “match the fretboard radius”. Let’s analyze this and see just how foolish and wrong it is.
First, should the strings match the fretboard radius? The industry has universally accepted that each string should be a certain height above a certain fret on a specific instrument.
Which fret to measure at, and what heights to aim for, are all topics for another day. Today, we’re just focusing on angling saddles to match fretboard radius.
So if we agree to set each string at a certain measurement above a certain fret, that in itself, assures that the strings are following the fretboard radius.
How? Well, the fret we’re measuring from is radiused, right? And if we set each string to a certain height (depending on manufacturer specs) above that fret, then we’re measuring from a point beneath the string, between the top of the fret and the bottom of the string.
If we have six strings, we’re measuring from six different points on the fret. The fret is bent (i.e.: “radiused”) and therefore each measurement is following the radius, and thus each string is following the radius.
The question now comes down to this: Must you angle the saddle to achieve this? (“This” meaning having the string heights follow the fretboard radius.)
And the simple answer is, “Absolutely not!” So what is achieved by angling each saddle. (We’re talking about saddles with two height adjustment screws, where one side can be a different height from the other).
If you have one screw shorter than the other, the longer screw takes the greater amount of tension, leaving less stress on the shorter screw. This can allow the shorter screw to vibrate loose, causing the string height to change and potentially, other issues.
Per geometry, if you change the height of one side, you change the height of the center by half that amount.
Also, allowing the saddle to lean to one side adds tension and friction to the side as well as the bottom of the saddle slot. Most saddles have not been engineered to accept this force on the sides of the groove. For instance, many saddles are highly polished at the slot bottoms, but not their sides. This may or may not make much of a difference but if it does, it is not likely to be a positive difference.
Angling your saddles to form to the fretboard radius is merely a sign that the instrument owner is not familiar with the laws of physics and geometry. Don’t be that guy!
