Radius Mismatch?

[johnbiscuti]

I've had my 1987 X-170 for a few weeks now, and I've had mixed feelings about it. It's a very well built guitar, great sound, looks beautiful, but I can't seem to get the action low enough (bridge is bottomed out) or feeling "right" and I'm having trouble understanding why exactly.

It kind of hit me last night while playing it - it feels like the radius of the bridge is not the same as the radius of the fretboard.

I don't have tools to back this up, but before I go down this rabbit hole, has anyone heard of this before on Guilds? I know it's VERY common on Gretsch guitars and that most serious players upgrade those bridges to one where the bridge radius matches the fretboard radius.

 

[richly harmonic]

Hey johnbiscuti, congratulations on your 'vintage' X-170 :redface-new: and welcome to the forum.

I have a Tru-arc aluminum bridge that I bought earlier this year in an attempt to comepensate for my 'would-be' Starfire III, but I wasn't entirely happy with the purchase-experience from Sweetwater, so I returned the guitar, but I still have the Tru-Arc bridge with me.

I don't think having a slight mismatch would be too much of a problem, say if you had a 9.5" fretboard radius, and a 11 or 12" bridge/saddle radius, just that maybe the outer strings (6th, 5th, 2nd, 1st) might be slightly further from the fret-board than was is normal for a closely matched radius/fret-board/bridge ratio.

I've played some brand new Taylor (Baby Taylor) acoustics last weekend at Tom Lee's in Hong Kong, and I was quite pleased by how comfortable the action and radius was. And you know what, the radius of bridge saddle was around 9.5/10"-ish, and the fretboard at 12" (from what I recalled asking at the store).

I'm sure there'll be others here shortly to help chime in on these perspectives.

Again congratulations on your Guild, and wishing you many sessions of great music time.

Best,
RH

 

[adorshki]

I've had my 1987 X-170 for a few weeks now, and I've had mixed feelings about it. It's a very well built guitar, great sound, looks beautiful, but I can't seem to get the action low enough (bridge is bottomed out) or feeling "right" and I'm having trouble understanding why exactly.

John I don't recall seeing mismatchde profiles mentioned before, usually only the question about whether a replacement will work on a given guitar, but that leads me to wonder if you're certain it's the original bridge?
Or even if maybe previous owner had fretboard re-profiled?

 

[NYWolf]

I have X 170, and there's a few problems with this guitar: the radius of fretboard is super flat! You can't fix it with TruArc or anything like that, because they don't make them flatter than 12'. Secondly, the bridge bottomed out because the neck angle is very shallow. It's inherited design flow, and that's why a lot of X170 needed a neck reset(i came across this phenomena when I was searching for mine.) I don't think you can do much about those issues, it is what it is, sorry to say. My solution was just use the lighter strings (010 with wound 3rd). The guitar otherwise is pretty well built, has nice tone, and pretty versatile too. However, I keep it as just the backup.

 

[Walter Broes]

What NYWolf said - there seem to be quite a few X170's out there with a very weak neck angle. Re: bridge and fingerboard radius match : if the guitar has a wooden bridge saddle, that should be very easy to fix for a repair guy.

 

[DThomasC]

I agree with Walter; this is probably fixable without a neck reset; bridges can be modified for lower action. If there's a radius mismatch then two birds, as they say.

I've removed material from the bottom of the saddle, where it rests on the thumbscrews to lower the whole thing. It's easy to do yourself and largely invisible. Pick up another bridge to experiment with if you're unsure.

 

[cc_mac]

First of all, It's a beautiful guitar. I took a serious look at it when it was for sale earlier this year. Although the owner couldn't explain the extra holes it seemed likely that someone had taken a run at using a Bigsby B3 or equivalent Guildsby on it. The situation with the neck angle and bridge was apparent form the pics and I guessed it would have had break angle issues with a Bigsby. As stated above the fix for the situation is to rework the bridge saddle. One can remove material from the bottom and thumb wheel notches to lower the action. If done carefully it's almost unnoticeable and the effect on tone would be minimal to negligible. It's possible the bridge radius does not match the fretboard but that is also something that can be dealt with. It could be as simple as the sting slots are worn deeply or unevenly. You have a great guitar there and once that is sorted out

I've often wondered why Guild did not build these and other hollow and semi-hollow with more of a neck angle.

 

[Guildadelphia]

A TOM style bridge could also be modified for a lower profile just like a wood bridge......some judicious filing or grinding of the underside of the bridge where it contacts the height adjustment screws (some older Guilds actually came stock with factory modded TOM style bridges to compensate for the neck angle). Some TOM's are also lower profile than the stock wood bridges to begin with. Also, depending on how thick the wooden brdge base is, the feet of the bridge base could be filed down a bit also. With either, you just need to be careful that you don't loose to much break angle over the bridge.

 

[cc_mac]

You are quite correct. I've given up the search for a low profile TOM as there aren't really any that I can find on the market new and the older Gibson ones are quite expensive. I have friend who is a machinist and is will to modify a TOM for me. He has the tools to make short work of it I've just got to decide which new one to buy. I'd like to find one that can survive having about 4 to 5 32nds taken off the bottom.

 

[Guildadelphia]

With regards to what TOM style bridge to use, stay away from the MIK or MIC imports....it's not that they are terrible quality, but they tend to be taller (especially the saddles) than other TOM style bridges. Gotoh makes a very nice ABR1 style bridge that isn't too $$$$ (under 30.00) and is the same dimensions as a regular ABR1 except instead of the saddle adjustment screws being held in place by a wire, they go through the bridge body similar to a Nashville style TOM so you don't get the rattles. The ABR1 type bridges that Walter Broes likes from Philadelphia Luthiery Supply are also very nice and quite reasonably priced.

 

[cc_mac]

Thank you for those tips.