Collapsed ABR…

[jeggz]

Ain’t played the Goldtop conversion in awhile, broke it out and something was weird.

ABR collapsed.

Slapped a Historic abr I had laying around and alls well in hell, but I can’t help being depressed.

 

[strayedstrater]

Condolences.

68 years (give or take) is a pretty good run for a piece of crappy cast zamak. Some others are still soldiering on, but a lot of them gave up the ghost decades ago.

If it hasn't cracked you could bend it back. You won't get another 68 years of continuous use out of it, but you could just put it on for special occasions.

And/or you could put the saddles and screws in a new bridge chassis so you have the minimum amount of new metal.

 

[mdubya]

I think Gruhn's or Glaser has a method to restore them.

 

[strayedstrater]

Various approaches, all the same basic idea. A few shims and either a bench vise or a clamp, slowly and gradually increasing the pressure until it's straight.

The only critical thing is to stop when it's straight. Don't try to overbend it into a slight upward arch hoping that it will take longer to collapse again -- that will crack it.

The second pic is probably the ideal way to do it. Especially for a repair shop that does it frequently. But thousands of ABR's have been straightened using the other two ways. (Wood shims are probably better than the metal shims in the first pic to avoid scuffs and dents).

 

[mdubya]

And/or you could put the saddles and screws in a new bridge chassis so you have the minimum amount of new metal.

Great suggestion.

 

[jeggz]

I’m thinking I can try and bend it back with a clamp and a lil care.

 

[strayedstrater]

I’m thinking I can try and bend it back with a clamp and a lil care.

ABR's can stay straight for many years after collapsing and re-straightened.

But the grain/crystal structure of the zinc alloy is internally weakened so it won't stay straight as long as it did originally. And every time it collapses and gets re-straightened it gets weaker, until it eventually cracks.

Raising the tailpiece or top wrapping reduces stress on the bridge. If you don't already have it set up that way you might consider doing that. Lighter gauge strings help if you could tolerate that.

Swapping bridges is a bit of a pain, but if you anticipate leaving it unplayed for a long period of time you could extend the life of the original by putting the new bridge on it when not using the guitar. (Could just loosen the strings when storing it, but ideally you should loosen the truss rod when you slack the strings for an extended period.)
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There are several replacement bridges that are more accurate than Gibson's Historic. Even if you straighten the original you might consider a really good replacement for everyday, long-term use. (And again, the vintage saddles and screws should last forever so you could pop them into the new bridge.)

 

[jeggz]

Who’s the bees knees repro ABR in 2025?

 

[jeggz]

 

[Brazilnut]

That's some helpful info there, mates! Thanks!

 

[jeggz]

FIXED!!!!!

Now we see how long it holds, I’ve raised my tailpiece a good bit up from decked, and went from 50-11 to 50-10 hybrid strings.

 

[boogieongtr]

I've tried pretty much everything out there and the best one made today are the 4 Uncles. As close to vintage as you can get. They're pricy but worth it in my book. You can make a maple wood blank and place it under the ABR1. Once you get your string height, make the block curved to fit the guitars top and the bottom of the ABR1. No more collapse.

 

[jeggz]

Gonna see how a set of Ultra Slinky’s feel on these two conversions. Maybe it’s for the best on the old ABRs.

They both had 50 40 30 18 15 11
Now it’s 50 40 30 17 13 10
The UltraSlinkys are 48 38 28 17 13 10