Bridge shaving

[fhubert]

This is a quote from Mathew Larrivee in the Larrivee guitar forum.


"It's an issue that opens a can of worms for many people. As there are a group of "internet forum readers" who believe it is not a valid way to adjust the guitar. Both Jean and I, Taylor, Martin, Collings, and virtually every other maker disagree with them.

Our bridge starts off at around 10.5mm and you can safely take the bridge as low as 7.0mm with no loss in tone or stability. We basically use a rectangular orbital sander and some hand sanding to do it. We also manufacture special bridges (9.5, 9, 8.5, 8, 7.75, 7.5, 7.25, and 7mm) that we use for repairs. The bridge usually requires some extra dremel sloting to reset the string break angle as well.

The primary reason this is done is not that neck join has changed, but rather the back of the guitar has either swollen or collapsed due to moisture change which forces the neck block to slightly move in turn giving the apearance that neck angle has changed. For example I had a lady come in this week from San Diego whos guitar was swollen like a football. Her action was a mile high because the back of the guitar had swollen up shifting the neck forward. She had lowered the saddle and there no room for it to go lower. So we removed about 2mm from the top of the bridge and reset the break angle - the string height at the 14th fret went from 8.5/64th to 5/64th with room on the saddle to spare to try and get lower if she wanted. It's a quick and easy permanent fix that doesnt require the risks and damage of a neck reset."

[zabdart]

If the bridge on your guitar starts growing a beard, I suggest you take it to see a doctor. Otherwise, I see no reason to shave your bridge.

[Bridgepin]

Originally Posted by Hurricane Bob

Here is what she looks like right now after sanding--a definite improvement in play-ability, tempted to continue...

OUCH, I'm glad the guitar plays better, but now you have some other issues.

[zhunter]

Originally Posted by Stony32

I think of the break angle as being the angle caused by the string breaking over the saddle, where, in geometric terms, the line from nut to saddle intersects with the line from the saddle to the bridge. If you lower the bridge by shaving the bottom, you increase (widen) that angle because the geometry is changed in the line from the nut to the bridge. Theoretically, if the top of the saddle is close enough to the top of the bridge and the bridge is shaved enough from the bottom, the break angle I am referring to is 180 degrees (straight line from bridge to nut). So, as you can see, dealing only with the angle from bridge to saddle only gives you half of the story in terms of downward pressure on the saddle.

It has a miniscule effect on the angle off of the front of the saddle.

hunter

[flagstaffcharli]

Originally Posted by fhubert

This is a quote from Mathew Larrivee in the Larrivee guitar forum.


"It's an issue that opens a can of worms for many people. As there are a group of "internet forum readers" who believe it is not a valid way to adjust the guitar. Both Jean and I, Taylor, Martin, Collings, and virtually every other maker disagree with them.

Our bridge starts off at around 10.5mm and you can safely take the bridge as low as 7.0mm with no loss in tone or stability. We basically use a rectangular orbital sander and some hand sanding to do it. We also manufacture special bridges (9.5, 9, 8.5, 8, 7.75, 7.5, 7.25, and 7mm) that we use for repairs. The bridge usually requires some extra dremel sloting to reset the string break angle as well.

The primary reason this is done is not that neck join has changed, but rather the back of the guitar has either swollen or collapsed due to moisture change which forces the neck block to slightly move in turn giving the apearance that neck angle has changed. For example I had a lady come in this week from San Diego whos guitar was swollen like a football. Her action was a mile high because the back of the guitar had swollen up shifting the neck forward. She had lowered the saddle and there no room for it to go lower. So we removed about 2mm from the top of the bridge and reset the break angle - the string height at the 14th fret went from 8.5/64th to 5/64th with room on the saddle to spare to try and get lower if she wanted. It's a quick and easy permanent fix that doesnt require the risks and damage of a neck reset."

Some posts come along with a bit more authority than others.

My CEO-7 currently has a nice set-up but little saddle left. It does appear to have a fairly tall bridge. Knowing that Martin uses a variety of bridge thicknesses, I'm going to take some measurements before rushing into a $400 repair that pulls the neck off my otherwise beautiful guitar. If the string height off the top is still in spec, it would seem shaving or swapping out for a new, shorter bridge would be an easier and more appropriate repair.

Certainly on cheaper guitars, shaving the bridge is a sensible way to keep a guitar playable.

On the other hand, my old Guild F-212 looks like it will need a neck reset next time the action changes. That's life.

Originally Posted by flagstaffcharli

...My CEO-7 currently has a nice set-up but little saddle left. It does appear to have a fairly tall bridge. Knowing that Martin uses a variety of bridge thicknesses, I'm going to take some measurements before rushing into a $400 repair that pulls the neck off my otherwise beautiful guitar...

Martin's "standard" bridge height is 11/32", or approximately 0.340". If the bridge is much taller than 0.340", shaving it down to that is appropriate as long as the saddle height is about 0.090"-0.125" with the desired action. An overly tall bridge means an overly heavy bridge, and that kills tone and volume.

[flagstaffcharli]

Originally Posted by Todd Yates

Martin's "standard" bridge height is 11/32", or approximately 0.340". If the bridge is much taller than 0.340", shaving it down to that is appropriate as long as the saddle height is about 0.090"-0.125" with the desired action. An overly tall bridge means an overly heavy bridge, and that kills tone and volume.

Thanks & will keep this in mind when I measure!

[mitcher16]

I had a Larrivee C05 for a while and I found it difficult to play over an extended amount of time. The break angle was off and it did look like a neck reset was in need. I actually phoned Larrivee and talked to Matthew and he walked me through the process of sanding down the bridge to allow me to lower the saddle a little more. After a few hours, mission accomplished and the angle was correct, guitar was easy to play and there was no loss in tone whatsoever. It was a great and somewhat easy fix.
Cheers.

[Steve Christens]

Originally Posted by fhubert

This is a quote from Mathew Larrivee in the Larrivee guitar forum.


"It's an issue that opens a can of worms for many people. As there are a group of "internet forum readers" who believe it is not a valid way to adjust the guitar. Both Jean and I, Taylor, Martin, Collings, and virtually every other maker disagree with them.

Our bridge starts off at around 10.5mm and you can safely take the bridge as low as 7.0mm with no loss in tone or stability. We basically use a rectangular orbital sander and some hand sanding to do it. We also manufacture special bridges (9.5, 9, 8.5, 8, 7.75, 7.5, 7.25, and 7mm) that we use for repairs. The bridge usually requires some extra dremel sloting to reset the string break angle as well.

The primary reason this is done is not that neck join has changed, but rather the back of the guitar has either swollen or collapsed due to moisture change which forces the neck block to slightly move in turn giving the apearance that neck angle has changed. For example I had a lady come in this week from San Diego whos guitar was swollen like a football. Her action was a mile high because the back of the guitar had swollen up shifting the neck forward. She had lowered the saddle and there no room for it to go lower. So we removed about 2mm from the top of the bridge and reset the break angle - the string height at the 14th fret went from 8.5/64th to 5/64th with room on the saddle to spare to try and get lower if she wanted. It's a quick and easy permanent fix that doesnt require the risks and damage of a neck reset."

Gee - doesn't this directly contradict about half of the posters on this thread who said the OP was nuts to even consider sanding down his bridge? I think I might tend to give Matthew's advice a bit more weight.

[Slight Return]

Originally Posted by fhubert

This is a quote from Mathew Larrivee in the Larrivee guitar forum.

"It's an issue that opens a can of worms for many people. As there are a group of "internet forum readers" who believe it is not a valid way to adjust the guitar. Both Jean and I, Taylor, Martin, Collings, and virtually every other maker disagree with them.

Our bridge starts off at around 10.5mm and you can safely take the bridge as low as 7.0mm with no loss in tone or stability. We basically use a rectangular orbital sander and some hand sanding to do it. We also manufacture special bridges (9.5, 9, 8.5, 8, 7.75, 7.5, 7.25, and 7mm) that we use for repairs. The bridge usually requires some extra dremel sloting to reset the string break angle as well.

The primary reason this is done is not that neck join has changed, but rather the back of the guitar has either swollen or collapsed due to moisture change which forces the neck block to slightly move in turn giving the apearance that neck angle has changed. For example I had a lady come in this week from San Diego whos guitar was swollen like a football. Her action was a mile high because the back of the guitar had swollen up shifting the neck forward. She had lowered the saddle and there no room for it to go lower. So we removed about 2mm from the top of the bridge and reset the break angle - the string height at the 14th fret went from 8.5/64th to 5/64th with room on the saddle to spare to try and get lower if she wanted. It's a quick and easy permanent fix that doesnt require the risks and damage of a neck reset."

I'm assuming the special bridges they have are simple replacements, which would mean removing the old bridge and replacing it with a thinner one, and also that they wouldn't have to dremel out the slot on those replacement brdiges. i.e. effectively the same as removing the bridge and sanding the bottom down.

Not that either method is superior; just different ways to skin a cat. And if you're comfortable deepening saddle slots cleanly with a dremel, using an orbital sander on top of the bridge and doing that would certainly be faster than removing, sanding, and re-gluing the bridge.

I'd assume they only do that because they have the manufacturing set up to do so; if you have a bridge that would fit perfectly that's already the thickness you need....it's like if you had a perfect bone saddle of the perfect size. You'd just drop it in as a replacement, you wouldn't waste time making a brand new one.

I got my 12 string bridge down to around .260", which is just a little shy of 7mm. The wings are around .060" - .070".

Currently my action is around 5/64" on the high E string at the 14th fret.

6/64" on the low E string at the 14th fret.

That's with a saddle height of roughly .117" on the high E side, and .165" on the low E side. Everything right now is rough fit and I haven't lowered the saddle; simply had a compensated bone saddle in a drawer and sanded the ends down to the fit the slot since it was about 1/4" too long.

It's good to know someone has said you can safely go all the way from 10.5mm to 7mm with no loss in tone or stability.

If anything, I'd imagine the tone would improve a bit since you're effectively lightening an external brace on the guitar.

[Slight Return]

I'd also like to add that while I've never tried a Thompson Belly Reducer, removing the bridge and sanding it from the bottom would give you the opportunity to use something like this to fix the belly in the acoustic top while the bridge is off.

I've experimented a little with my homemade Go-Bar deck, simply putting some cauls on top of the bridge and clamping it with go bars to flatten the top.

It did seem to work. I think I forgot about it and left it clamped for a week or so. No heating and no bridge removal required.

But with the Thompson method I could see how heat could be helpful. The only thing that concerns me is how permanent this really is. Tops can change continuously throughout their life and I'm not sure if or when they ever reach a point where they're fully bellied out or completely done moving. I flattened my 12 string top, for example, with the Go-Bar deck....but after a while with string tension back on it, it's headed back to where it was.

I'm not sure if a Thompson belly reducer used with heat would get any different results in the long term. After all, acoustic guitars are constantly trying to fold themselves in half. Daily string tension for years is gonna have much more weight in the long run than even a few weeks of clamping pressure.

Unless instead of keeping your guitar on a stand or in a case you keep it clamped on the bridge in a Go-Bar deck whenever you're not playing it

Anyway, if the guy from Larrivee does it, I'll probably reconsider offering bridge shaving as an option to customers, especially after that comment about how you can safely take a bridge down to 7.0mm without worrying about any change in tone or stability.

And sanding from the top down, provided you're set up to cut saddle slots, would be much less time consuming than removing, sanding, and re-gluing the bridge.

However, on bridges that are lifting up and need to be re-glued anyway, I think in that scenario sanding the bridge on the bottom makes the most sense. If you're gonna have it off the guitar and have to reglue it anyway, you might as well do everything in one go.

Especially on cheaper guitars, though, where people want lower action, bridge shaving seems like it would be good to add to my arsenal. Kind of exciting to think about, actually, since most of the time lowering the saddle [which is usually already very low] and adjusting the truss rod doesn't do a whole lot. It helps a little, more in some cases than others, but.....

...I'm currently retracting my statement about never doing this to customer guitars. Only reason I can see is I wasn't aware of it as a legitimate option and have just never thought about offering it as a service to offer. I've only lowered the bridge to get the action better on bridge re-glue jobs. Never considered or was even aware people did top-down sanding of securely attached bridges just to lower action.

I'll be thinking about this for sure. Of course I'll get the routine down on a few of my guitars first, but I get the idea. Thanks to everyone here for commenting and opening my mind up, this is pretty exciting stuff to me.

Also, another note:

I also recommend John Pearse "Slightly Light" strings to people sometimes, which I think can help a little with bellying compared to .012-.054 sets.

(The Pearse set is 011, .015, .022, .030, .040, .050 and IMO feel great)

[meredith]

Originally Posted by fhubert

This is a quote from Mathew Larrivee in the Larrivee guitar forum.


"It's an issue that opens a can of worms for many people. As there are a group of "internet forum readers" who believe it is not a valid way to adjust the guitar. Both Jean and I, Taylor, Martin, Collings, and virtually every other maker disagree with them.

Our bridge starts off at around 10.5mm and you can safely take the bridge as low as 7.0mm with no loss in tone or stability. We basically use a rectangular orbital sander and some hand sanding to do it. We also manufacture special bridges (9.5, 9, 8.5, 8, 7.75, 7.5, 7.25, and 7mm) that we use for repairs. The bridge usually requires some extra dremel sloting to reset the string break angle as well.

The primary reason this is done is not that neck join has changed, but rather the back of the guitar has either swollen or collapsed due to moisture change which forces the neck block to slightly move in turn giving the apearance that neck angle has changed. For example I had a lady come in this week from San Diego whos guitar was swollen like a football. Her action was a mile high because the back of the guitar had swollen up shifting the neck forward. She had lowered the saddle and there no room for it to go lower. So we removed about 2mm from the top of the bridge and reset the break angle - the string height at the 14th fret went from 8.5/64th to 5/64th with room on the saddle to spare to try and get lower if she wanted. It's a quick and easy permanent fix that doesnt require the risks and damage of a neck reset."

Thanks for this! Looked all over the forum for just this information. I have a Yamaha Nippon Gakki FG 180 that is not worth a neck reset, but still want to get a few more songs out of. I needed to know how low I can shave the bridge, and voila! Thanks fhubert.

[lar]

After reading through all the posts, I'm curious why no-one thought that the low saddle height could be due to the top bellying (raising up).

If the top is bellied, that would raise the action, which would cause someone (the OP or Luther) to sand the saddle down to obtain a lower action - to the extreme.

Is this a possibility?

[Aaron Smith]

Originally Posted by lar

After reading through all the posts, I'm curious why no-one thought that the low saddle height could be due to the top bellying (raising up).

If the top is bellied, that would raise the action, which would cause someone (the OP or Luther) to sand the saddle down to obtain a lower action - to the extreme.

Is this a possibility?

It is a possibility, but it's also easy to diagnose. A straightedge across the lower bout would tell whether the top radius has changed; an inspection with a mirror inside would also tell if some braces had pulled loose.

[brianhejh]

I have a Gibson J50 ,the bridge was ramped about 8 years ago. The straight edge currently just clears the bridge top. Action at the Low E is 6/64 treble e 5/64.

The treble e has almost no clearance at the ramp and I believe is now affecting the tuning.

My question: because it is one string would the easy fix be to route out the ramp a little more or slot the bridge or both to obtain a fix.
Are there other options?

Thanks

Brian