Pinless Bridge Questions
 

1. Do pinless bridges typically have a bridge plate installed under the guitar top? Do they need one if the answer to 2. (below) is no?

2. Do pinless bridges typically have 2 small posts/dowels serving to help offset shear force?

3. Would you recommend a pinless bridge?

Edited for clarity.

Bridgeplate, yes. It not only serves to resist string ball wear on pin bridges, but it ALSO reinforces the top against excess belly and peeling of the bridge. Some classical guitars (which primarily use pinless bridges) don't have bridgeplates, but they only have about 60% of the tension of steel strings.
IMHO, installing shear pins is of limited use. Bridge joints almost always fail by peeling off, starting on the back edge.

John - thanks for the reply! I think you might have misunderstood - I'm asking about pinLESS bridges.

Does a bridge plate still serve the same functional utility in a pinless setting?

Yes bridge plates are necessary.

I have a mid to late 60s Regal that the old bridge came of by pulling the back of it and slitting the bridge in two leaving the front.

I removed the remnant, cleaned the footprint of the old glue and used original titebond and clamps to glue the new one in place.

I was considering converting to a pinned bridge, but the old bridge held for 20+ years so the new one should perform just as well.

It had a couple of countersunk holes on the lower part of it but I opted out of using screws to help hold it in place. That's right where the old bridge split in two and with out the screws it might have pulled off in one piece instead of two.

If you have never done this I suggest taking it to a luthier if possible. It was not possible for me, so I watched tons of ytube "bridge" videos and had a very good idea of how it's done and why.

Good luck

Ron

I can only speak about my Lowdens, but they have a bridge-plate - presumably for the reason John Arnold spoke about, i.e. to reduce bellying.

There are no dowels or screws in the Lowden bridges, they are secured by glueing alone.

I’m a novice, building my second guitar, so keep that in mind as you read my words.

First question -
YES, bridge plate.

Second -
I’ve discussed with my mentor .. a veteran of 50 guitars made and hundreds repaired.. about putting a pin-less bridge on my current build project.
When asked if some sort of attachment aid was advisable,
he stated that glue alone was sufficient to hold the bridge to the top.. no pins needed to offset sheer.
Not one of his builds have ever had a glued bridge joint fail.
Nor has any of his re-glue repairs failed.

Third -
I was hoping you would get more specific answers to this from those with more experience, as I’m considering doing so.
I don’t see a downside to a pin-less bridge, but they are certainly not common, leading me to wonder why?

I think it has a lot to do with tradition and the conservative nature of guitar buyers generally. Bridge pins are traditional.

Breedlove alone probably accounts for tens of thousands of guitars with pinless bridges and they've been building them that way for almost 30 years. Breedlove is one company that hasn't been terribly constrained by tradition in their designs.

Just built a guitar to gain experience with pinless bridges. I found it a serious PITA to set up. With a pinned bridge it's easy to relax the strings and remove them to attend to the saddle. Not so for my pinless bridge. On the good side, a string change is easy, no messing with pins or monitor wear on bridge plate. But for me, I've had the experience and I don't want to build another with a pinless bridge.

That is what I was referring to, see my edited reply. Obviously, attaching the strings from underneath (pin bridge) means that the bridge will not fly off the top if it loosens. If the bridge flys off the top, it can pull top wood north of the bridge with it, particularly if the top has runout.
I am not a fan of pinless bridges, and it is not just because of the failure mode. Pinless bridges are not nearly as convenient when changing saddles.

Can’t dispute your ‘changing saddles’ point in any way, but that’s not something the average player does with any kind of regularity. Changing strings, however, is a different matter, and it’s a simpler, speedier process with a pinless bridge, and with less possibility of making mistakes - e.g. failing to seat ball-ends properly, string-windings ‘hanging up’ in the pin hole or on the pin, etc.

So, from the POV of a player who’s had both kinds of bridge for the past twenty-five years or so (and, FWIW, never had a bridge of either kind ‘fly off’, or even come loose), and with all due respect to your experience and expertise as a luthier, as a player I tend to prefer the pinless style.

The usual disclaimers apply......IMHO, YMMV etc.

The pins may help keep the bridge from flying off and killing the cat, but it doesn't seem to me from my old repair experience that they reduce the damage to the top. If anything, a pinned bridge tends to end up distorting the top more, and that's particularly true of things like bolts and screws. As to whether pinless ones come up more frequently, I don't know if there's enough real data on that. More steel string guitars are made with pinned than pinless bridges, and we tend to notice rarities, so when a pinless bridge does come it you remember it. But without accurate data as to the relative numbers out there I don't think we can really say which is more likely to come loose when properly done. From what I understand the actual stress levels in the glue line are much the the same, and it's the maximum peeling load along the back edge that dictates when the bridge starts to come up.

Pinless bridges have improved over the years because they have screws to reinforce them & use a double bridge pad. The technology is more updated than it used to be.

IMO, if anything, adding screws or bolts makes a poorer joint.

My 30 plus year old Takamine 12 string with a pinless bridge is still in perfect playing condition. A little over built perhaps but still plays and sounds great. No screws or bolts that I can see looking inside.

My only personal experience is owning a Lowden for 25 years with no hint of bridge lift, so I'd look to their design if you're doing a pinless bridge.

Conversely, I've owned exactly two Chinese manufactured "popular name brand" acoustic guitars with regular pinned bridges, both of them having the bridge lift after a year or two.

The lesson I learned is it is more about design and correct gluing practices instead of pinned vs. pinless.