Q: I understand the difference between a standard humbucker and a Trembucker, but what on earth is “F-Spacing?” And why do I need to know about it?
A: F-spacing refers to the widest spacings on full-sized humbucking pickups. For correct string alignment and a balanced output, F-spaced humbuckers should be used in the bridge position on guitars with string spacing at the bridge of 2.1″ or 53mm (or greater). If the nut width is 1-11/16″ or 43mm (or greater) F-spaced pickups can be used in the neck position. Why two different standards? Originally the electric guitar world was pretty much split between Gibson and Fender designs, and one of the differences (besides scale length) was string spacing. Gibson typically chose a narrower string spacing at the bridge than Fender, so the polepieces on Gibson humbuckers would be closer together than the magnets on Fender pickups. When guitar shops (and serious do-it-yourselfers) started installing humbuckers in the bridge position of Strats, the strings didn’t line up with the polepieces. If the top and bottom E strings were too far outside the polepieces, the sound could suffer. Floyd Rose-equipped guitars have string-spacing the same as Fender spacing, so it naturally evolved that these pickups were called “F-spaced.”