Does shimming a neck affect the ability to intonate?

[Lazarus.Bird]

Hi guys. Recently picked up a beater bass. I was going through giving it a full setup. I'm not incredibly experienced but have become quite good at getting my basses just how I like them. The strings needed raised around the 12th fret so for the first time I shimmed a neck. Just used the thickness of 2 business cards and it put my action right where I needed it to be.

I always do intonation last, so I'm not sure how this bass intonated before the shim. When I went to adjust the intonation, I ended up having to tighten the E and A screws all the way and it is still a little off. I plan on buying a replacement bridge with more intonation travel, but did shimming the neck somehow make those strings impossible to intonate? Thanks.

[allexcosta]

Originally Posted by Lazarus.Bird

but did shimming the neck somehow make those strings impossible to intonate? Thanks.

Impossible to intonate? No...

Does it change intonation? Yes...

[stflbn]

Just in case...

Moving the saddles toward to the neck sharpens the note. (Shortening the string)
Moving the saddles away from the neck flattens the note. (Lengthening the string)

[Lazarus.Bird]

Right. Fretting the E and A strings at the 12th fret results in a sharp note, even though the saddles are as far from the neck as possible. Maybe it was already close to maxed out to intonate and shimming the neck put it over the threshold. In general does something like a Hipshot bridge give you more travel on the saddle? The bridge/body is design as a string-thru and I'm hoping I can drop a better bridge right into the same area so the string-thru holes line up and I can properly intonate.

[Hellbastard]

What kind of bridge is installed? Is it possible to gain more saddle travel if you remove the tension springs off the bridge?

Given the fact that it is a string-through bridge will make more difficult to find a suitable replacement. Remove the bridge and check if you have room to move it back a 1/4" or so, while keeping the string-though holes aligned. Maybe that'll help you achieve better intonation.

[stflbn]

Have you tried it strung up Top Load rather than string through?

[Lazarus.Bird]

Here is the bass. I don't have any close ups of the bridge but could take one later. You can kind of see how the bridge is in the picture I posted: NWUBD (New World's Ugliest Bass Day) - VJ Rendano Pro III Designer Model

And stflbn, no I have not. Maybe I should try that. I've never noticed much different between top load and string thru.

[SurferJoe46]

Originally Posted by allexcosta

Impossible to intonate? No...

Does it change intonation? Yes...

Unless shimming the neck makes the neck shorter, I don't see how you can say that.

Worst possible case, the neck swings up in a very small arc and might get a few thousandths of an inch shorter - but that's really nit-picking.

[Lazarus.Bird]

Originally Posted by SurferJoe46

Unless shimming the neck makes the neck shorter, I don't see how you can say that.

Worst possible case, the neck swings up in a very small arc and might get a few thousandths of an inch shorter - but that's really nit-picking.

This was the assumption I was making, just wanted to verify. Thanks for the input!

[JLS]

Maybe it was already close to maxed out to intonate and shimming the neck put it over the threshold.

If this is a cheap import, as your other thread implies, the combination of questionable bridge placement at the factory, as well as a bridge w/o much adjustment range, comes into play. Going to flats can exacerbate this, ad they may require more adjustment range.

And, no, your shimming didn't cause this.

Have you given these strings a witness point, where they break over the saddle? This can be the magical cure, for many a bass intonation problem.

[pnut166]

Could you just move the bridge back a hair ?

[Lazarus.Bird]

Originally Posted by JLS

If this is a cheap import, as your other thread implies, the combination of questionable bridge placement at the factory, as well as a bridge w/o much adjustment range, comes into play. Going to flats can exacerbate this, ad they may require more adjustment range.

And, no, your shimming didn't cause this.

Have you given these strings a witness point, where they break over the saddle? This can be the magical cure, for many a bass intonation problem.

I'm sorry, could you please elaborate? I'm not quite sure by what you mean by witness point. I will say that the angle they come through the string thru combined with the fact they are flats creates kind of an awkward meeting point for string and bridge.

[stflbn]

Witness point = hard break point where the string goes over the saddle.

"Often" when you put new strings on a bass the strings curve over the saddle rather than make a hard angled break over the saddle. A curved angle can effect tone and intonation.

Take your fingers and push down fairly hard on each string in front and behind (at the same time) of each saddle. Mostly important for the lower bigger strings.


Odds are the bridge on the bass is to far forward.

[pacojas]

Originally Posted by Lazarus.Bird

I'm sorry, could you please elaborate? I'm not quite sure by what you mean by witness point. I will say that the angle they come through the string thru combined with the fact they are flats creates kind of an awkward meeting point for string and bridge.

is there a slight break-angle in the string where contact with the bridge saddle terminates?

how far out is your intonation? (a few cents ain't bad)

[pacojas]

Originally Posted by stflbn

Witness point = hard break point where the string goes over the saddle.

sorry to be redundant,... i type very slowly.

[Lazarus.Bird]

It's been a few weeks since I fiddled with it. I'll have to check tonight and report back. I have plans of refinishing this bass and changing a bunch of hardware so I'll probably end up replacing the bridge anyways. Just need to verify if I need to install it a little further back on the body.

[electracoyote]

Originally Posted by Lazarus.Bird

I'm not sure how this bass intonated before the shim.

For this reason, you will never know the impact the shim made on intonation. The bass may not have intonated without the shim.

Depending on the amount of shimming you did, if you put a pretty severe upward angle on the neck, it may have reduced the scale enough to make it impossible to intonate with the current bridge.

The only way to know for sure is to remove the shim, return the bass to its original configuration, and then try to intonate. Short of that, like you said, move on and look for a bridge with more saddle travel.

I would also suggest not shimming a neck until you have done everything else to improve the way a bass plays, including fret leveling, touching up the nut slots, and setting the intonation. Shimming is a last resort. Because setting intonation means moving the saddles, this in turn effects action and other aspects. You can't really know what you're dealing with until you go through the whole list of set-up details.

[Lazarus.Bird]

The neck definitely needed shimmed. Lowering the bridge saddles all the way didn't lower the action enough for me. The action near the nut was fine.

[electracoyote]

Originally Posted by Lazarus.Bird

The neck definitely needed shimmed. Lowering the bridge saddles all the way didn't lower the action enough for me. The action near the nut was fine.

That's probably true, but not taking a few minutes to intonate it first put you in a bit of a quandry. Now you're not sure whether you need a bridge with more saddle travel, or if the bridge was seated incorrectly and you need to drill for a new bridge placement.

[JLS]

Depending on the amount of shimming you did, if you put a pretty severe upward angle on the neck, it may have reduced the scale enough to make it impossible to intonate with the current bridge.

How would that, "reduce the scale length"?