Slotting a Badass bridge

Many bass players swear by the Badass bridges, invented and manufactured by Leo Quan. They’re well built, drop right on to a Fender bass without modification, and some say it improves the tone and feel of the bass. They’ve been in such high demand for decades that many bass manufacturers install them stock. But a Badass bridge installation isn’t complete without slotting the saddles. Many Badass bridges don’t come slotted from the manufacturer, presumably to allow the player to dictate string spacing. Unfortunately, many bassists aren’t aware that their bridge needs some attention, and they just play them as is. The problem with playing an unslotted Badass is obvious: the string spacing isn’t even, and every time a string is plucked the string can move, imparting a sloppy, loose feel. Worse, the notes can sound undefined and lack a solid fundamental, as the string doesn’t have a definite witness point at the bridge saddle. No fun!

Today I slotted a Badass V bridge. You can see in this first picture that the string spacing is uneven, and the saddles have tell tale marks from where the strings have slid back and forth during playing, especially on the A and G strings:

When slotting a Badass bridge, one can’t just start hacking away at it – it takes careful measurements to get it right. I do an almost complete setup on the instrument before I start working on the bridge. It sure would suck to slot the bridge only to discover later that the neck wasn’t lined up in the neck pocket, and the strings were all listing to one side!

I begin by lining up the outer two strings with the last fret on the fingerboard. It’s important to set it far away enough from the edge, so the strings won’t accidentally pull off the side of the fingerboard. I usually set them around 2-3mm away from the beginning of the frets bevel:

Once I’ve gotten the outer strings exactly where I want them, I mark the saddle with a razor blade, and then very carefully make a notch for the outer strings in the saddle. I use joint edge round files, sized just slightly over the strings diameter, to make each cut. As I’m getting the cut started, I set the file against my fingernail to keep it from sliding all over the place, and I always back angle the cut slightly so the string has a solid witness point:

Once the outer two strings are set, now comes the fun part: the MATH! (cue shrieking violins here)

It’s imperative that the string spacing is dead even. I opt to go for an even space between the edges of the strings, as opposed to measuring from the center of the strings. Why? Well, because bass strings have a very wide range of gauges, from the very thin to the very thick. If I were to measure from center to center, the spaces between the strings would be narrower between thicker strings than the thinner ones. If a player later decides to use some crazy thick strings, the edges would be very close to each other, and the entire bass could feel pretty odd. (If you don’t agree, take it up with Anthony Jackson.)

Calculating the string spacing is actually pretty easy. I measure the space between the string with a set of digital calipers, measuring 71.68mm (pay no attention to the measurements indicated in the pictures – it’s hard to hold both the camera and calipers steady):

Then I measured each of the three inner strings, getting 2.5mm, 2.11mm, and 1.63mm. From here, it’s just simple arithmetic:

– 2.50
– 2.11
– 1.63
= 65.44

So the total space available between the outer two strings, minus the inner three strings, is 65.44mm. Since we need four spaces between the strings, we divide the available space by four:

/ 4
= 16.36

So, now we know the space between the edges of each string is 16.36mm. I set the digital calipers to 16.36mm, and space the strings accordingly (again, pay no attention to the display in the picture):

Once I’ve got each of the strings set exactly where I want them, I again very carefully mark their locations on the saddles with a razor, and file each slot with the appropriate file. The slots don’t have to be very deep – just enough to hold the string in place:

And that’s all there is to it! Once the Badass saddles are slotted, all that’s left to do is set the radius and intonation, and it’s all done! Hooray, math!

Permanent link to this article: