Help with my PS CU24 Trem

Deadgrateful

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Hey all. New here and relatively new to the world of PRS. They’ve quickly become my favourite guitars and I’ve added a Modern Eagle Quattro, a Modern Eagle V Wood Library and a Private Stock CU24 to the stable.

The CU24 is from 2011 and has a very special set of 53/10’s. Sound like pure heaven and is significantly more ‘stratty’ and quacky in positions 2 and 4 than the MEV (ash body contributing to that possibly! Just a hell of a guitar…

One issue though: the trem is basically decked on the pivot screws. It’s either touching the top or is 10th of a mm from it. The back can’t be parallel as there would then be no backwards movement. This is necessary as the action is where I want it (1.5mm on both bass and treble and 12th and 17th fret) and the saddles are as low as they go. The truss rod is perfectly adjusted with 0.15mm under the 8th fret.

Is this going to cause me problems long term, and will it mark/wear the top of the guitar or the trem knife edge at all? It’s quite far off PRS factory specs which seems odd being a Private Stock.

Any help would be much appreciated!

Will post pics of the guitars once I reach the required post count
 
I would first fire off this exact question to PRS as they would be your first line of contact.
Will definitely do that, but would also be interested to hear from peeps here that might have a similar issue (if it even is an issue)
 
.015 is a lot of relief for a PRS ( IMHO) even .010 is more than I usual need.
Can you post a few pics of the set up , how low is you action at the first / second fret ?
an an extreme case I would sand the bottoms of the saddles to give me some play room to get the 1/16th ( ish off the body )
 
.015 is a lot of relief for a PRS ( IMHO) even .010 is more than I usual need.
Can you post a few pics of the set up , how low is you action at the first / second fret ?
an an extreme case I would sand the bottoms of the saddles to give me some play room to get the 1/16th ( ish off the body )
Firstly, thanks for taking the time to help me! I think I need another post before I can share an image but will try doing so shortly.

Regarding the relief, I’m in the UK so metric. 0.15mm is 0.006” which (I think) is just in the middle of what PRS list as factory specs.

Action at the first fret is just under 1/64th and just under 1.5/64 at the second. Although take those with a grain of salt as it’s hard to measure such a small gap. It’s pretty much the same as my other PRS’s though from what I can tell.

Sanding the bottoms of the saddles would be fine for a sliver, but I’d need to take off over a mm to get the front of the bridge raised to factory specs
 
When you get to the point where you can post pictures, some of the bridge would be helpful too. It is really easy to not have the trem level. I have seen people get this wrong a lot.

My SAS has the trem really close to the body in the front. The front edge on the low E side just barely misses the body. It hasn't been an issue at all. As long as it isn't dragging or hitting it is good.
 
From your pictured, the trem is not level. You need to tighten the trem claw screws just a bit. Try 1/4 turn on each then retune the guitar. The base of the trem should be level with the strings. The height of the trem looks okay from what I can see in the pictures. You are right, the finish of the guitar makes it a little hard to see exactly where it is. From the various pictures and angles, it looks like it is okay.

One way to tell if the trem is touching is to put a piece of thin paper under the front edge then push down on the trem arm and see if you can easily pull the paper out from under it.
 
Let's see if these pics work! It's hard to see because of the reflections but the bridge at the front is a hair away from touching the top of the guitar. Oddly it doesn't seem to be dragging but I'm not experienced enough with PRS trems to know for sure.

ArwGSK7.jpg

3uAIXY0.jpg


Yah you need new/modified saddles that will get you where you want. I would probably recommend comprising your setup instead and learning to play with a higher action. I do the opposite of you and actually raise the bridge to get a full step bend when pulling up
 
From your pictured, the trem is not level. You need to tighten the trem claw screws just a bit. Try 1/4 turn on each then retune the guitar. The base of the trem should be level with the strings. The height of the trem looks okay from what I can see in the pictures. You are right, the finish of the guitar makes it a little hard to see exactly where it is. From the various pictures and angles, it looks like it is okay.

One way to tell if the trem is touching is to put a piece of thin paper under the front edge then push down on the trem arm and see if you can easily pull the paper out from under it.
Yea it's not level, but if I level it there's literally no upward movement. The way it is at the moment I can get fSharp from the Low E (which I thought was recommended). Should I adjust the claw to reduce this movement as you suggest then?
 
Thanks dude, but I think the SS trem unit is set up quite differently from a normal PRS term?
They look different and the SE SS has only two screws on top, not six.

But I was mostly showing you the way the gaplooks between the body and underside of the trem baseplate when set up to float.

You could try setting yours up like that regardless of whether it's a six screw or two screw mount.
 
Yah you need new/modified saddles that will get you where you want. I would probably recommend comprising your setup instead and learning to play with a higher action. I do the opposite of you and actually raise the bridge to get a full step bend when pulling up

Thanks for the help but there's no way in hell I'm learning to play with a high action on a 10k (new) guitar... This thing should be darn near perfect!

I don't understand how a Private Stock could have left the factory so far from spec. If I put the trem where it's supposed to be (1/16) then the action is literally unplayable. It's in slide guitar territory.

Any idea where I can get these modified saddles you mention?
 
They look different and the SE SS has only two screws on top, not six.

But I was mostly showing you the way the gaplooks between the body and underside of the trem baseplate when set up to float.

You could try setting yours up like that regardless of whether it's a six screw or two screw mount.
Will give it a go. It's not far off how I have it now, but with more upwards movement! Thanks my dude
 
Hard to say without trying, or doing some calculations beyond my understanding, but I would think that you are getting some rise out of your string height due to the back of the bridge being raised. I think you can raise the six screws to their proper height and lower the back side by increasing the spring tension and you will come up with the result you are looking for. The top of the saddles will fall with the lowering of the back side even if you raise the front edge.
 
Yea it's not level, but if I level it there's literally no upward movement. The way it is at the moment I can get fSharp from the Low E (which I thought was recommended). Should I adjust the claw to reduce this movement as you suggest then?
You definitely want the tem to be level. It may not stay in tune well when you use the trem if it is not level. It affects how the strings reseat in the saddles when it goes back under tension. It will probably lower the string action a bit if you tighten the claw screws a little. There isn't a lot of upward movement in a PRS trem.

The pivot screws can be adjusted to set the overall height of the trem. You have to be very careful how you do this so you don't damage the knife edges on the trem base plate. I have adjusted a good number of these over the years.
 
Hard to say without trying, or doing some calculations beyond my understanding, but I would think that you are getting some rise out of your string height due to the back of the bridge being raised. I think you can raise the six screws to their proper height and lower the back side by increasing the spring tension and you will come up with the result you are looking for. The top of the saddles will fall with the lowering of the back side even if you raise the front edge.
Thanks but unfortunately I already tried this. The top of the saddles do fall but by an incredibly small amount when the back of the bridge is tightened.

You definitely want the tem to be level. It may not stay in tune well when you use the trem if it is not level. It affects how the strings reseat in the saddles when it goes back under tension. It will probably lower the string action a bit if you tighten the claw screws a little. There isn't a lot of upward movement in a PRS trem.

Ah ok, makes sense I guess. I'll tighten the claw a bit
 
Thanks but unfortunately I already tried this. The top of the saddles do fall but by an incredibly small amount when the back of the bridge is tightened.



Ah ok, makes sense I guess. I'll tighten the claw a bit
Not sure if you saw the other part I added to my reply after I posted it about the pivot screws. Another thing having the trem in a not level position does is it affects the intonation, also due to how the string seats in the saddle. Get it level first, then adjust the saddles. I am not sure what your overall goal is with the action and where it is not doing what you want it to do.
 
Not sure if you saw the other part I added to my reply after I posted it about the pivot screws. Another thing having the trem in a not level position does is it affects the intonation, also due to how the string seats in the saddle. Get it level first, then adjust the saddles. I am not sure what your overall goal is with the action and where it is not doing what you want it to do.
Cool, I’ll definitely level it out then. My goal is to have a playable action without the front of the trem rubbing the top which it seems to be at the moment!
 
Thanks for the help but there's no way in hell I'm learning to play with a high action on a 10k (new) guitar... This thing should be darn near perfect!

I don't understand how a Private Stock could have left the factory so far from spec. If I put the trem where it's supposed to be (1/16) then the action is literally unplayable. It's in slide guitar territory.

Any idea where I can get these modified saddles you mention?
Sorry no, I’ve never had this issue as I play most comfortably with an action between 1.5-2mm at the 12th fret. I can’t play with low action, I end up grabbing other strings if I do a big bend on the G-B-E strings with lower action.

I am also mystified that a private stock instrument couldn’t get you an action you wanted without changing the bridge height.
 
Let's see if these pics work! It's hard to see because of the reflections but the bridge at the front is a hair away from touching the top of the guitar. Oddly it doesn't seem to be dragging but I'm not experienced enough with PRS trems to know for sure.

ArwGSK7.jpg

3uAIXY0.jpg

XNipiGP.jpg

UygLdB6.jpg
The back of your trem is bit high IMHO , you should not have any issues with the front of the trem hitting the body looks OK to me
 
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