The Mod Squad
Gigs are back! Are we ready? Er… no. Some peculiar things are going on and Dave Burrluck needs to fix ’em
Getting ready for my return to playing live, I realise I need to spend a bit of time giving my gigging guitars some love. Now, it’s not like I’m Dallas Schoo and I’ve got The Edge on the phone saying he needs his 20-something gigging guitars all restrung and in tip-top condition before five o’clock. Nope, I’ve just got the two: one for the main stuff, the other for slide. Simple.
That said, I’m a bit embarrassed when I pull out my slide guitar, which I haven’t used since October 2020. Do strings corrode and fingerboards get gunkier just from a guitar being in a gigbag? Or did I forget to give it a wipe down after its last hurrah? My main guitar, a start-up ultrabasic-spec Knaggs Kenai, has had plenty of use over these past pandemic months as a reference for any relevant review I’m writing. And before that it had been a workhorse for a couple of years before gigs stopped. A bit of a clean-up, then, some new strings and I’ll be done.
But then I notice something odd. The tune-o-matic-style bridge (aka TOM) has sunk – or collapsed, which seems a rather dramatic term. What I mean is that the top of the bridge, which should be straight, now shows a noticeable concave curve [pic 1]. It’s not much, but it means that the saddle radius, which was 305mm (12 inches), is now a little flatter, the central strings are closer to the frets and, well, it doesn’t feel quite as ‘right’ as I remember. The bridge is a pukka Gotoh part, and regular readers will know I’m a big fan of its wares. I can’t quite believe what I’m seeing.
Now, tune-o-matics can have a tendency to sink like this over the years, but I’ve only experienced this once before on a low-end Tokai with its generic cheap TOM. ‘Has the guitar been bashed?’ suggests a mate (who’s as long in the tooth as I am and has never experienced such an issue, either).
The Knaggs uses a proprietary Influence bridge setup where the anchor bar (which is not height-adjustable like a normal stud tailpiece) does pull the strings down at quite an angle, slightly sharper than a normal TOM/stud tailpiece setup. I drop Peter Wolf at Knaggs an email with a picture just to check if this has been an issue. He answers in the negative.
There’s a good chance that you could straighten it by removing the saddles and clamping the bridge in a large bench vice with a hardwood or metal spacer placed on the underside, for example. You could also hammer the base with the top of the bridge (again, with saddles removed) on a flat piece of metal. Can’t do any of that? You might have a mate who’s better equipped. But there’s also the chance that you could crack the bridge, too, which on anything remotely collectable or vintage is not what
“I notice something odd. The tune-omatic-style bridge has sunk… its top has a concave curve”
you want. To be honest, while I’ll happily remove the saddles from that cheapo Tokai bridge and give it a bit of a bash – which successfully straightens it and proves it can be done – I decide to simply order up a replacement.
Which TOM?
This should be straightforward, but like pickups and other hardware parts there’s quite a choice, not only in brands but in finding the right fit. I’m tempted simply to order the same bridge, but my hesitancy comes from two places: first, if it’s failed once it might happen again; and, second, Knaggs has now moved over to TonePros. So I decide to look at that option first and keep it in the family.
There are basically two types of TOMs: the original ‘narrow’ ABR-1 style and the later, wider ‘Nashville’ style. By narrow, I mean around 10.7mm in width whereas the Nashville is wider at just under 14mm. This means there is more distance that each saddle can travel, so if the bridge posts are slightly off in terms of position, for example, then a Nashville’s wider adjustment range might help you intonate the guitar correctly. The limited travel of the ABR-1 means the original placement of the bridge has to be that much more accurate.
The majority of TOMs have the same spacing of the two post holes (approximately 74mm or 2.913 inches) and typically the holes are a little larger than the diameter of the posts so there’s a little wiggle room. However, there are three main post-hole diameters [pic 2], confounded, as usual, by metric and imperial sizes. Many import guitars use a large post, often with a very handy-toadjust slot head: the diameter here is typically 6mm. The more vintage accurate TOMs have smaller-diameter threaded posts that, of course, screw directly into the top. This is, Tone Pros tell us, a 6/32 US thread (UNC) that has a specification diameter of 0.1380-inch (3.5mm), so you’ll often find smaller-diameter holes (typically 3.75mm) on that style of ABR-1. Large-scale hardware makers such as Gotoh work in metric and, aside from that larger post-style option, seem to stick to 4mm diameter posts with a hole of around 4.4mm. There are some exceptions, notably the tune-o-matic used by large production maker Samick for many years, which had a post spacing of 71mm – but you can buy conversion posts from WD Music UK, for example, that’ll solve that problem. If you can speak to a supplier or email them before you order, I’d recommend it.
Then we’ve got the material to think of: the body of the bridge and the saddles themselves. Unhelpfully, Gotoh doesn’t tell us what its Nashville bridge is made of – the base or saddles are not magnetic so it’s not steel and it’s probably a zinc alloy known as Zamac, Zamak or Mazak. Now, Wikipedia tells me these are “a family of alloys with a base metal of zinc and alloying elements of aluminium, magnesium, and copper… part of the zinc aluminium alloy family[,] they are distinguished from the other ZA alloys because of their constant four per cent aluminium composition.” Gawd. There are plenty of other options, not least machined zinc alloy, brass, aluminium and
“All I wanted to do was to get ready for a gig and I’m now deep in the rabbit hole of materials”
steel. Saddles can be made of that same alloy, or brass, steel, titanium, not forgetting nylon, and then there are the ‘string saver’ friction-reducing composite saddles made by Graph Tech. Gawd, again!
All I wanted to do was to get this guitar ready for a gig and I’m now deep in the rabbit hole of materials and their sounds. I have no problems with the guitar or the way it sounds. Will that change, though, maybe for the worse? When it comes to ordering the ‘right’ part, it’s far from a simple decision. Ultimately, though, if Knaggs is using TonePros right now, that’s good enough for me, so I simply go for the TonePros Locking US Fit tune-o-matic, small post, notched saddle with a code number T3BP-N. Got that?
Refitting The TOM
Depending on the bridge you buy, it may or may not be notched: each saddle has a slight groove in its centre that will stop the string from slipping sideways. Some notches are really quite extreme Vs – and I suggest you avoid these; like the nut, the string needs to sit on the saddle with only about 50 per cent of its diameter actually going into the saddle. So a lightly notched TOM means that you can precisely ‘sit’ each string [pic 3] with the same files you use for your nut. Just like a nut, each saddle groove needs a good exit and entry point. You can certainly do this with some fine needle files, and if you’ve got a Bigsby involved then you really need to smooth the slots carefully and apply some lube every time you restring.
If your saddles are unnotched, all the above applies, but you obviously need to make sure you centre each string slot on the saddle. A quick way to do this is to string up and get the strings all sitting correctly on the saddles. Then mark either side of each string with a fine Sharpie (or other similar marker pen). This will give you two lines and then you can notch each saddle in the centre with a fine ‘V’ needle file then open out each slot as above. Personally, I usually do this by eye, using the adjustment screw as the guide for that initial notch. And, of course, don’t forget to reintonate your new TOM [pic 4]!
“Things move, frets wear, tuners get slack… it all happens quicker on guitars you’re playing live”
Final Clean & Tweak
It always surprises me how my gigging guitars take such a battering. I’m hardly throwing them around and probably play much less aggressively than I did a few decades ago. The thing is, you don’t always notice the wear. Things move, be it necks or Fender saddles, frets wear, batteries go flat, tuners get slack, output jacks get loose – and it all happens a lot quicker on guitars you’re playing live, often for extended sets in probably sweaty boozers.
So, if you’re also in the process of getting back to gigging, now’s the time to get your maintenance routines up to muster. Let us know how you get on!