Sunday, March 13, 2011

Floyd Rose

This is heavy nerd, feel free to skip.

When I was working on Ed's guitar yesterday, I took some time to reacquiant myself with the whimpering horror of the Floyd Rose Double Locking Tremolo.

This beast was invented in the mid-1970s by a chap called Floyd Rose (bet you didn't see that one coming). He came up with it because he wanted a tremolo that you could go Jimi Hendrix-style mental with, without pulling your guitar badly out of tune. In that regard, he succeeded—when properly set-up you can do just about anything with a Floyd Rose and it won't have any serious effect on the tuning. That, in my view, is about the only way in which he succeeded.

The Floyd Rose is a wildly impractical piece of technology. In order to restring a guitar with a Floyd Rose you have to first chop the ball-ends off the strings, then clamp them into the saddles at the bridge (to do this properly you must turn the set screws so hard that you will inevitably strip quite a few allen keys over the years). Once they're all in you have to spend ages tuning the strings, letting the bridge adjust—which pulls them back out of tune again—then tuning them again. It typically takes a day or two before you actually have a guitar that is both in tune and has a balanced tremolo. If you're switching between string gauges or brands of strings it can take even longer. Once this is done, you have to clamp the strings in place at the nut, making large adjustments to tuning a fiddly and laborious process.

If you you try and change the tuning of an individual string (say switching to Drop-D tuning) then this will lower the overall tension on the tremolo, pulling all of the strings out of tune. Similarly, if you break a string, the increased tension on the other strings pulls them all out of tune, and sometimes causes more to break. The second fact makes it foolish to gig with a Floyd Rose equipped guitar unless you have at least one backup.

Ed has made several modifications to his Floyd Rose over the years (including adding extra springs and placing a block of wood under the rear of the tremolo) which essentially make it into a single-action tremolo, like the Wilkinson Tremolo on a Strat. This makes it less versatile as a tremolo unit, but makes it much, much easier to use.

Even so, the actual tremolo unit is a pretty shocking piece of design. The set screws that allow you to adjust the intonation are positioned underneath the strings, so you have to remove the strings in order to make any adjustments the intonation. You cannot raise or lower the saddles individually, which means that you can only adjust the action by tightening or loosening the bolts that anchor the unit in place. Also, the clamps that hold the strings into the bridge are positioned at a 90ยบ angle to the string pull, which makes the strings more likely to break at that point.

All told, a guitar with a Floyd Rose Tremolo is like an old Rolls Royce where the driver's seat is not covered by the roof. It's a design feature that assumes you have staff to do everything for you, as it would be really unpleasant to do it yourself.


I replaced the busted barrel-jack on my Yamaha bass the other week (a relatively simple but very fiddly bit of wiring) and that reignited my urge to tinker with guitars. I can't begin round three of Ben vs. Refinishing (see these posts) until the weather improves, so the other day I took the opportunity to abduct Ed's guitar (the Stratobastard) for a quick bit of maintenance.

It's been more than three years since I made the alterations described here. Surprisingly, the electrics in the guitar seem to be holding up well—there aren't any settings that make it go dead, nor any that crackle or hiss. The only electrical issue worthy of mention is the fact that the pickup housing on the neck pickup becomes live when the pickups are switched into series. I know how to fix this, but I don't have the tools, nor the balls to do it just yet (It involves cutting the pickup casing open with a dremel-like  tool and creating separate ground wires for the casing and the signal ground). I'll sort that out one day, but it's not a pressing issue right now.

The main reason I wanted to get this guitar back on the workbench (it's a figurative workbench, obviously, as I do most of my tech work sitting on the floor in the attic) was because of a fretwork issue I noticed during its overhaul. I didn't have time to fix this problem back then, so the action has always been far too high for my tastes. Ed has never had a problem with this, but it has always bothered me. If he wants high action because he likes it that way, then that's fine, but I don't want the stratobastard to have high action because it's impossible to play otherwise.

I spent a few minutes raising and lowering the action, playing scales, and staring down the neck until I went cross eyed. Some day, I'll buy a set of relief measuring tools, but for now I'm more comfortable assessing the state of a guitar by eye and ear. What I figured out was that the guitar was suffering from a condition I call "the hump," where the fretboard has warped slightly around the neck join. It's something that happens as guitars age, and as the neck-wood settles into the join. It's another one of the reasons that I'm going off the idea of ever buying guitars that are less that 5 years old.

Ed's guitar didn't have the worst case I've ever seen, but it was bad enough to make the guitar unplayable beyond the 12th fret. The 15th fret, in particular, stood 2-3mm proud of its neighbors on the treble side. Extreme cases of the hump (the likes of which I've only ever seen on old mandolins) can only be treated by defretting the neck and planing down the fretboard, but this one was mild enough to be treated be re-profiling and re-crowning the frets (using techniques broadly similar to the ones outlined here)

While I was doing this I made a few very minor adjustments to the truss rod, to straighten out the neck a little, and fiddled around with the intonation on the tremolo. The end result is a dramatic lowering of the action, with none of the buzzing or dead notes that caused problems before, and once again, I managed to do the whole thing without injuring myself. Huzzah.