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Mosrite bridge problem

Posted: Sun Nov 22, 2009 10:00 am
by Sarah93003
I've searched the forum and could not find an answer to my question. On my Celebrity is a Mosrite roller bridge. The little rollers all function just fine. I notice that this bridge tends to rock forward on the two pins instead of sitting parellel to the top of the guitar. Is this normal? Someone, either the previous owner or my luthier, put a piece of wood under the front of the bridge apparently to restrict it's pitching movement. Obviously this should not be there. It is making me wonder if my bridge is worn out in some way.

Yesterday I put on new strings which allowed me to adjust the tremelo arm to snug it up a bit. After putting the strings on it seems that the action is significantly higher than it should be. I'm thinking this is from the bridge moving or some other condition that I'm not aware of. At the last fret the E string is about 3/16" above the fretboard and this seems high to me. Sorry about the grainy pictures, my iPhone doesn't have a flash and I'm out of batteries on the regular camera. :D

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Re: Mosrite bridge problem

Posted: Sun Nov 22, 2009 11:13 am
by Veenture
I'll take a stab at it for what it's worth Sarah. My Hallmark bridge looks very similar to the one on your Celebrity and I would conclude that if there is NO way you can make standard adjustments to the bridge to tighten it up (rings, washers etc.?) and so ban that undesired pitching movement -which adversely effects tuning stability, I would have to think of wear although that seems unlikely. My Hallmark bridge does not pitch in the slightest way.

Did you put on thicker gauge strings? My Hallmark bridge rollers all have individual roller measurements, i.e. each slot/groove is designed to accommodate the thickness of each (!) designated string. On yours the higher action may be due to a thicker E string possibly now sitting higher on the roller saddle (I take it you are referring to the LOW E string).

Maybe your luthier inadvertently changed the bridge's adjustments? (I thought I could detect a slack washer on one of the bridge posts?) :?

Re: Mosrite bridge problem

Posted: Sun Nov 22, 2009 11:16 am
by jtr654
Your missing a screw in the front left of your trem. When was the last time you intonated your guitar? from the picture it looks like the bridge was misplaced when made because all the saddle are forward of center. If it Inonated at where it is than don't do anything to it except lower the bridge. Yes 3/16" is high for the Mosrite. The bridge is fine.

Re: Mosrite bridge problem

Posted: Sun Nov 22, 2009 11:48 am
by TerryTNM
Well I notice one thing right off the bat. I would check the intonation. All the string saddles are as far forward as they go except the 6th string. If indeed it is close to intonation then the bridge itself is located to far back. The bridge tilts because the bridge saddles are all forward of the bridge posts (It looks like that's why the piece of wood is in there). You might end up having to relocate the bridge. Ideally, you'd like the string saddles to be positioned fore and aft of the posts equally. As far as the string being to high it would just be a matter of lowering the bridge but check to see it the neck is bowed. Also a note: the higher the strings the more sharp your notes will be especially at higher register so keep that in mind when you check your intonation. Just chiming the note at the 12th fret is not enough you should fret pick it to set your intonation. preferably with an electronic tuner.

Hope this helps.

-Terry

Re: Mosrite bridge problem

Posted: Sun Nov 22, 2009 6:25 pm
by Sarah93003
Thank you all for your feedback.


1. I'm currently using 10's on this guitar but thought of switching to 11's. I tired out some Earnie Ball strings and I don't care for them.

2. The intonation is way, way off. I'll have to start over and figure this all out. The last setup was done by a local luthier who is really terrific. I don't know why all of the bridge saddles are in front of the posts but that makes perfect sense why this thing is tilting forward.

I think I'll disassemble the whole thing, check out all of the little parts, and go from there. Thank you all!

Re: Mosrite bridge problem

Posted: Sun Nov 22, 2009 6:33 pm
by GattonFan
This problem was resolved later on when the tops of the adjustable post were threaded, and locked down with either an acorn nut, or plain nut. At any rate, if you have enough post showing through the bridge, it can be threaded. If not, you can get those bridge posts (occasionally) on eBay. The nut locks the bridge down to the post - a simple solution.

Dennis

Re: Mosrite bridge problem

Posted: Sun Nov 22, 2009 6:56 pm
by Sarah93003
jtr654 wrote:Your missing a screw in the front left of your trem. When was the last time you intonated your guitar? from the picture it looks like the bridge was misplaced when made because all the saddle are forward of center. If it Inonated at where it is than don't do anything to it except lower the bridge. Yes 3/16" is high for the Mosrite. The bridge is fine.



There are only two screws that hold this time of tremelo onto the top. The hollowbody models did not get the Vibramute or tremelo with four screws. And, yes the intonation appears to be a mile off. I'll correct that.

Re: Mosrite bridge problem

Posted: Sun Nov 22, 2009 6:58 pm
by Sarah93003
GattonFan wrote:This problem was resolved later on when the tops of the adjustable post were threaded, and locked down with either an acorn nut, or plain nut. At any rate, if you have enough post showing through the bridge, it can be threaded. If not, you can get those bridge posts (occasionally) on eBay. The nut locks the bridge down to the post - a simple solution.

Dennis



Thanks Dennis. That is a great idea. There isn't enough post sticking above at the moment, but when I take it apart I should be able to see a solution such as you describe. Great!

Re: Mosrite bridge problem

Posted: Sun Nov 22, 2009 8:10 pm
by handbrake
Hi Sarah,
I didn't read anyone discussing string tension, so I thought I'd bring it up. You might expect higher action if your replacement strings have a higher tension that pull the neck forward.

I use D'Addario strings (not an endorsement, simply a fact). It's my experience that the Mosrite necks have enough natural strength that 9s will not provide any relief in the neck. 10s end up being the lightest string I can use. They provide just enough relief to lightly tighten the truss rod against.

One particular guitar (that '73 Celebrity) needed more tension than usual for a playable action. I noticed that flatwound 10s had a little more tension than the regular 11s, so I bought a set and put them on to see how things would shape up. The neck is now in perfect relief and plays effortlessly.

In your case, if the action is to high with the heavier strings, you may want to counter that with a truss rod adjustment to suit your needs.

Just something else to consider.

Cheers!

P.s. I agree with the diagnosis regarding intonation and its effect on the bridge. Also, do the bridge wheels turn freely?

Re: Mosrite bridge problem

Posted: Mon Nov 23, 2009 10:26 pm
by Sarah93003
handbrake wrote:Hi Sarah,
I didn't read anyone discussing string tension, so I thought I'd bring it up. You might expect higher action if your replacement strings have a higher tension that pull the neck forward.

I use D'Addario strings (not an endorsement, simply a fact). It's my experience that the Mosrite necks have enough natural strength that 9s will not provide any relief in the neck. 10s end up being the lightest string I can use. They provide just enough relief to lightly tighten the truss rod against.

One particular guitar (that '73 Celebrity) needed more tension than usual for a playable action. I noticed that flatwound 10s had a little more tension than the regular 11s, so I bought a set and put them on to see how things would shape up. The neck is now in perfect relief and plays effortlessly.

In your case, if the action is to high with the heavier strings, you may want to counter that with a truss rod adjustment to suit your needs.

Just something else to consider.

Cheers!

P.s. I agree with the diagnosis regarding intonation and its effect on the bridge. Also, do the bridge wheels turn freely?



Thanks Reber,

I took everything apart so I can really get a feel for what all of the parts are doing. I found two little flat washers under the base of the bridge sitting on top of the bridge pins. The diameter of the bridge pin/post is 0.206" the inside diameter of the flat washers is 0.215 and the diameter of the holes in the bridge base is 0.212. The 0.006" difference in diameters allows the bridge to pitch forward by 10 degrees. The bridge pins only protrude 0.042" above the bridge base. Unless I remove the flat washers from underneath and then I get .100". I picked up some flat type speed nuts from Lowes (#10-24 and 3/16") but they aren't going to work. I think there is some sort of little star washer type gizmo that you can push down on a round cylinder and get it to "bite" and hold. Other than that, I think I may stop by a hobby store and get some .002-.003" shim material and go that route.

It's intertesting to note that the fretboard is a 7.25" radius while the bridge itself is 12"radius. I was surprised to find that much differnce. That is why I go with aftermarket bridges on my Gretsch guitars. I would be curious if the Hallmark bridge is the right radius.

I did check the little wheels and they all seem to be moving freely. I've cleaned the guitar and put some Guitar Honey on the fretboard as it was looking very dry. I'll put another application on tomorrow and then put this all back together. Hopefully by intoning this properly I won't have the bridge pitching forward. If I have to do a truss rod adjustment, I may be back here begging for instruction how to do that. :mrgreen: