Bridge Thickness different on Bass to Treble

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yakka
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Bridge Thickness different on Bass to Treble

Post by yakka » Wed Oct 04, 2017 3:22 pm

I am up to making the bridges for some guitars I am making, (first lot of builds). i use a couple of guitars at home to reference (also "The Gilet & Gore Books").
Looking at the bridges today I noticed the thickness of the bridge on the Bass side is thicker than on the treble side, is this for weight loss on the bridge, break angle something else intonation ?
the guitars are a 00 Gilet and 2 dreadnaught matons.
any opinions please!

regards
yakka
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kiwigeo
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Re: Bridge Thickness different on Bass to Treble

Post by kiwigeo » Wed Oct 04, 2017 6:39 pm

As far as a I know Trevor doesn't thicken his bridges on the bass side but if I'm wrong Im sure Trevor will correct me. On the steel string bridges in The Books the back of the bridge is beveled off so it maybe the beveling is giving a visual illusion that the bridge is thicker in places.
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Trevor Gore
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Re: Bridge Thickness different on Bass to Treble

Post by Trevor Gore » Wed Oct 04, 2017 7:46 pm

yakka wrote:
Wed Oct 04, 2017 3:22 pm
Looking at the bridges today I noticed the thickness of the bridge on the Bass side is thicker than on the treble side...
Usually that is done purely for aesthetic reasons so that the saddle protrusion is the same all across the the bridge, even though the action is higher on the bass side. It can save a bit of mass, but mostly, on factory guitars, the mass of the bridge is uncontrolled anyway. For factory guitars a bridge is chosen from a variety of thicknesses at hand, so that with the right action for the current guitar's neck set, a decent amount of saddle is left protruding for later adjustment. Bridge thickness can therefore vary by a few millimeters and the mass accordingly. This is one of the reasons why factory guitars vary a lot in their sound quality - the string height off the top is quite variable along with the bridge mass.

If you use string height above the top as a fixed dimension, (along with specified action at fret 12), the controlling variable is neck angle. That means you can use the same thickness of bridge from one guitar to the next. You can still taper it from bass to treble if you wish, but if you put CF in it, you don't want to cut into the CF when you taper it. You also need to think about where the taper on the wings ends, which means you have to put the taper across the whole bridge before you "scallop" the ends. So with composite bridges, it's a lot easier to keep the bridge the same thickness across.

Some builders come at it from the other direction... They keep the bridge thickness constant and the saddle protrusion the same from bass to treble by putting a slope on the fretboard (i.e. thicker on the treble side).

Whichever way you go, make sure it's easy for you to tool up to get it right.

yakka
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Re: Bridge Thickness different on Bass to Treble

Post by yakka » Wed Oct 04, 2017 8:38 pm

Thank you for the replies I will now get on with it.

jeffhigh
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Re: Bridge Thickness different on Bass to Treble

Post by jeffhigh » Thu Oct 05, 2017 10:48 am

On some brands, such as Martin, the bridge pins are quite close to the saddle, especially on the bass side, so having the extra support from a thicker bridge and the resultant lower protrusion, can be beneficial for the increased sideways load.

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