String Break Angle at the Bridge #1
For the last while I’ve been rambling on about string angle over the nut. Now, I’m going right down the other end. Let's talk bridges and tailpieces.
Specifically, Gibson bridges and tailpieces.
Gibson Tun-O-Matic Bridge and Tailpiece
As we’ve talked about, the angle a tensioned string ‘breaks’ over something like a nut determines the downward force onto that nut.
Same goes for bridges.
With the Gibson-style arrangement, the strings anchor in a tailpiece and then pass over the tun-o-matic bridge. The angle at which those strings meet the bridge is determined by the height of the tailpiece. Raise the tailpiece off the body and the string angle becomes more shallow. Lower the tailpiece towards the body and the angle steepens.
The Problem: Collapsed Bridge
While we want a the strings to have a good solid downward pressure over the bridge, too much pressure in this location can bring its own problems.
Namely, bridge collapse (or call it buckling, arcing, bending, whatever — it’s not good).
Over time, pressure on the tun-o-matic can cause it to sag in the middle.
This sagging means that your string radius and angle is no longer consistent.
Let me explain:
If your bridge is properly set up, your strings should match your fingerboard radius so that they have a consistent feel across the fingerboard.
When the bridge begins to collapse, the strings in the middle become closer to the fingerboard. Effectively, the action on these strings becomes lower and you might find these middle strings begin to buzz for (seemingly) no reason.
Repairing the Sagging Gibson Bridge
Sometimes, the saggy-bottomed bridge can be brought back to life. I’ve made a pretty simple jig that allows me to put the bridge in my vice and apply pressure to straighten it again.
I call it the Haze Tun-O-Matic Straighten-O-Matic. It’s just some maple shaped to the rough dimensions of a non-buckled bridge, with a top to protect the saddles during straightening.
Of course, it’s not always possible to straighten the bridge successfully. Sometimes, it’s just too far gone. Sometimes, the metal just doesn’t have the pliability to come back into shape without cracking. Sometimes, it just doesn’t work.
So, you can just buy a new bridge. Pop the original in the case for the vintage guitar buyer in fifty years. ;-)
Avoiding Gibson Bridge Collapse
You can avoid dealing with a buckled bridge (or having your straightened bridge buckle again) by altering the break angle over it.
Raising the tailpiece will make the string angle more shallow and will help prevent collapse. Personally, I’ll do this when setting up any Les Paul unless the owner has strong opinions otherwise.
Why might someone be against raising the tailpiece? Well, some feel that having the tailpiece bolted hard down to the body helps the tone/sustain. If you’re in this camp, you can still lower the tailpiece right down and reduce string break-angle by stringing over the tailpiece (insert strings from the front and wrap-over the top of the tailpiece).
The Gibson Neck Angle Lottery
The neck-set angles on Gibsons are annoyingly inconsistent. I don’t want to open another can of worms and introduce another ‘angle’ discussion but for now, just know this:
On some guitars you can screw that tailpiece right down and still have the perfect string break angle over the bridge. Other instruments may require the bridge be much higher off the body to get a good action and the tailpiece then has to be correspondingly higher.
Your guitar will probably not be the same as others so it’s impossible to give height measurements. Fun, eh?
So What Angle Should I Set?
Something like this one. Not too steep and not so shallow that it will cause any problems.
You can dial in a slightly different angle on each side if you want. Personally, I like to keep the bass strings a little more steep than the treble.
You'll certainly want the strings to clear the body of the bridge. Don’t have the strings touching the corner at the back of the bridge. That just makes me say, “Grrrrr.”
What About Through-Body Stringing?
Yeah. ‘Grrrr’ on this one too.
You’ll sometimes get tun-o-matic instruments with through-body stringing. You can’t adjust the tailpiece since there isn’t one. And the angle’s usually pretty steep.
Keep an eye on the bridge and, I guess, just get used to replacing or straightening it every now and then.