This is the second time in two week's I've gone to set up a relatively new US made SG and this happens. The original bridge has a radius of something in the 17 to 18in radius range, nowhere near the factory fretboard radius of 12. Made for a pretty awful setup before the problem was corrected. Is this as commonplace as I think it is?
they don't make 'em like they used to.
a couple of years ago while visiting Bobby Blue one of his teenage students showed up for a lesson. He jumped out of mom's Ferrari & proudly presented a brand new SG - his mom had just bought him. Insert drool/envy here. But it was painted - not clear as the old mahogany models were. You needed a crane to lift the old Gibsons - but the new one was light as a feather. How Gibson can be proud to affix their name to these beats me. I personally was not impressed.
I understand the late model Fenders are made in Mexico - where are these Gibsons now made?
Gibson has made over 50 DIFFERENT versions of the SG.
The ones made from '62-65 are usually light as a feather. They got just a bit heavier through '71 but are still considered lightweight. They were offered in Transparent Cherry and White with other custom colors available at a 10-15% upcharge).
In '71-72 the entire SG line went completely to hell. These were usually heavy as heck and are of little interest to serious players. IMO, all the SG's made until around 1982 are crap designs. In 1982, good repro's of early '60's SG's re-entered their line. They were again bastardized in the 90's in several oddball versions. This, unfortunately continues in the present.
Today there are "under $700 MAP" Gibson SG's (and Les Pauls) being made & sold that are embarrassments to the guitar world.
Today, Gibsons guitars are manufactured in Nashville & Memphis. Google for more info.
Fender guitars made in North America are manufactured in California, Arizona (CS models) and Mexico. Another Googling will provide additional info.
There are several comprehensive books available with more detailed information than I will provide. Check 'em out. They're all good reads.
Could the new bridge be meant for a compound radius fretboard? In that case, the bridge radius should not match the fretboard radius.
Old tuneamatics tend to collapse gradually under string pressure. The radius you find is usually greater than the radius the bridge started with.
When I was doing electric guitar repairs in the 70s this was very common for 10-15 year old tuneamatics or even younger ones, and our standard fix was to turn them over, put them on an anvil, and pound on them a bit until the arch was right, which is flat across their top--the arch for the fretboard is supplied by the saddle heights. They were pot metal then (are they now?) and could be broken by overdoing it, but I never cracked one by tapping it back to flat on top.
They're still zinc alloy, Howard. I've given up on pounding them into submission.
Today's aftermarket "quality" ABR-1's & Nashville's are so much better and less expensive than Gibson's version [my personal vote for 'best value' TOM's are Gotoh Japan) that they're more cost effective to replace than repair (that ones on valuable & original vintage instruments are the exception). I agree that, when prescribed, pounding them into submission IS an acquired art I'm happy I developed a couple of decades ago.
fyi: It seems that several more 'upscale' aftermarket suppliers are making ABR-1's & Nashville's in a tool steel alloy. They're twice to 3 times as expensive (@ wholesale) as the zinc versions. Someday, I'll be able to afford some for my personal instruments. THEN I can evaluate all the hype surrounding them.
The final radius is established by the string notches which need to be cut into the saddles. All bridge saddles on tune-o-matic style bridges are just a 'starting point'.
It's "set-up 101" stuff.
I used some of my radius gauges and tried to visually trace a line from the tip of each saddle where the string had left it on the original bridge, and I still got an improper radius. It may be just such that the factory never finished cutting the slots enough to establish a proper radius. The replacement was a dead on 12'' even before making considerations for filing, whereas the stock one was much flatter without any regards to notches. Either way with the factory bridge, the 12th fret measurements did get progressively lower than desired when working towards the center strings, so the job was still done wrong from the factory. I suppose that if I did encounter one with a compound radius, the bridge may have been proper for that instrument, but luckily both of them benefited from the swap.
I'm sorry, but you have it all wrong.
By varying the depth of the saddle slots, the final radius is established. This varies from instrument to instrument.
If you don't have Dan Erlewine's repair book, please order a copy ASAP. It completely explains what I'm trying to explain.
For future projects: don't trust anyone's factory spec's (ESPECIALLY Gibson's). That's why we guitar tech's exist. To fix their mistakes/oversights.
I don't see the need to be unpleasant. There was a clear difference in the saddle heights (prior to cutting) from the factory bridge to the one I used as a replacement. You say file them to depth, I say why not start with something that already has the proper radius and simply notch for the string as opposed to cutting deeper. Either way the proper result is reached, and it doesn't mean I need to go back and study my basics. Please remember when having a conversation that your opinion is not fact, it's merely opinion.
The factory radius at Gibson is established by spacing the strings over the saddles & hammering the strings tnto the saddles to create the notches. It's an UNSKILLED process and MUST be refined. BTW: They keep the hammered strings on the guitar right through shipping.
My description of the method is NOT opinion but industry accepted fact.
The REASON it's easier to set the radius with filing is because there are small variances in saddle height & size caused by the manufacturing process. If we 'want' mil-spec TOM's , we'd have to pay $400+ @ for them to get the consistency you require.
I wasn't being unpleasant, just factually honest. It's a lacking quality on this forum nowadays. Up until my reply, you got nothing but guesses and digressions. Howard's post was historically informative.
You're on your own from here on out.
Here's the same info from someone you may consider an expert.
You absolutely fail to see my OPINION that if they were to use a bridge that requires less manipulation we would all be better off. I have used the traditional method also and understood it well before you made mention of it. You come across as an absolute elitist. I won't be following MY post any longer now that it's been shit all over.