Shims: The lazy mans fix??

[202dy]

The problem was that during that period Fender necks were notorious for shifting in the pocket. The reason was sloppy machining and lack of quality control. Because it was a visible change from past design, three bolt necks with micro-tilt adjustment got blamed for neck movement. Ironically, G&L utilizes the same system for their instruments and no one complains about neck movement.

 

[electracoyote]

I'd be very interested to hear, from people who routinely use shims, why they do so and what constitutes a legitimate use of a shim.

I have some ideas for legitimate uses, mainly that the neck pocket is somehow flawed or too deep. I have shimmed basses for this reason, and it worked great.

But I wonder if people sometimes use a shim because they think it will remedy things like un-level frets or the infamous ski jump. Because I am of the distinct impression that is not the case.

Thoughts?

 

[David Jayne]

Thoughts?

You are correct on all counts. It's a way to fix too-high action and nothing more.

 

[electracoyote]

You are correct on all counts. It's a way to fix too-high action and nothing more.

Thank you.

And it's a very specific type of high action that can't be cured with the saddle height/bridge, nut slots, relief, etc..

I just wanted to confirm this. I suspect there are those people who use a shim inappropriately when it's something that a good fret level or fretboard planing would cure, and possibly to a better outcome. I have taken the shims out of basses and had myself or one of my techs correct another more pressing issue and viola! shim no longer relevant.

It's the mis-use of shimming that concerns me I guess.

 

[tbsodsmuck]

fenders and shims, like salt and pepper

 

[uOpt]

Some people here are confused.

Almost no Fenders have actually tight neck pockets. The 3-bolt mechanism did make things a lot worse since there was much less friction between neck paint and body wood (one side resting on the metal plate opposite the adjustment screw). But this wasn't made better or worse by different neck pocket quality in the 1970ties. The mechanism was a bad idea.

 

[David Jayne]

The mechanism was a bad idea.

Eh, my G & L has it. No issues. If the end of the pocket is tight, it can't move.

 

[David Jayne]

Thank you.

And it's a very specific type of high action that can't be cured with the saddle height/bridge, nut slots, relief, etc..

Absolutely. Last resort. But totally OK in my book.

 

[mongo2]

But I wonder if people sometimes use a shim because they think it will remedy things like un-level frets or the infamous ski jump. Because I am of the distinct impression that is not the case.

Thoughts?

I've put several basses with ski jump necks back into playable condition using custom shimming. While the neck can have such a severe flip that nothing short of a neck replacement will work, for the moderate flips I worked with, it put otherwise unplayable basses back into action.

 

[Britbonic]

I've put several basses with ski jump necks back into playable condition using custom shimming. While the neck can have such a severe flip that nothing short of a neck replacement will work, for the moderate flips I worked with, it put otherwise unplayable basses back into action.

Wow, what a thread!

I like this post cause it's a great (but not the only) example of using a shim when the alternative would be a very expensive fix. There's nothing inherently bad about shims but they are sometimes used as a quick fix instead of looking holistically at the problem. If you can get the saddles heights where you want them, best to start with the neck. Is there too much or too little relief? Are the frets level? Any other funky neck issues? Next I'd look at the neck pocket. Is the pocket relatively flat and level? What about part of neck that goes in pocket?

I seen and played basses where the shim was a quick fix and it ended up make other aspect of the bass worse from a playability standpoint.

 

[NWB]

I'd be very interested to hear, from people who routinely use shims, why they do so and what constitutes a legitimate use of a shim.

I have some ideas for legitimate uses, mainly that the neck pocket is somehow flawed or too deep. I have shimmed basses for this reason, and it worked great.

But I wonder if people sometimes use a shim because they think it will remedy things like un-level frets or the infamous ski jump. Because I am of the distinct impression that is not the case.

Thoughts?

My G&L JB has a Plek'd neck and so the frets are good to go. However, with the low action that I prefer the saddles were bottomed out. (yes, the truss rod was adjusted!)

A shim in the pocket solved the problem after all other setup aspects were taken care of.

 

[bazzanderson]

i've shimmed every single bolt on I've ever owned with a cut piece of business card. 1 to 2 cards in thickness depending on the neck route. I've never noticed a difference in feel or tone, just playability.

 

[electracoyote]

I've put several basses with ski jump necks back into playable condition using custom shimming. While the neck can have such a severe flip that nothing short of a neck replacement will work, for the moderate flips I worked with, it put otherwise unplayable basses back into action.

I don't understand the geometry behind this assertion.

Since a shim only changes the angle of the neck, a permanent ski jump should have the same impact on a shimmed or un-shimmed neck.

 

[electracoyote]

My G&L JB has a Plek'd neck and so the frets are good to go. However, with the low action that I prefer the saddles were bottomed out. (yes, the truss rod was adjusted!)

A shim in the pocket solved the problem after all other setup aspects were taken care of.

A legitimate use of shimming, as I have previously conceded. Obviously, in this case, the pocket-to-heel relationship was slightly off, and the neck sat too low in the pocket.

 

[thiocyclist]

Getting the saddles high enough to achieve good break angle is really important in my experience, so if a shim helps out with that too then they're worth more than I realized.

 

[T-Bird]

Hi.

Re. fixing ski jump with a shim.

I don't understand the geometry behind this assertion.

Since a shim only changes the angle of the neck, a permanent ski jump should have the same impact on a shimmed or un-shimmed neck.

On a long pocket where the shimming need is extensive, the leverage allows the misguided user (shimmer) using a thin shim at the end of the heel to cause the ski jump by tightening the neck screws too much.
Avoidable with a full shim .

When the shim is placed between the neck screws and the screws are tightened, the ski jump dissapears either immediately or over time.

Very common IME on the runt of the litter oriental imports back in the 70's and 80's.

Regards
Sam

 

[David Jayne]

Have to agree with Sam. Been there done that. It can work. But it's pretty sketchy.

 

[T-Bird]

Hi.

Been there done that. It can work. But it's pretty sketchy.

+1

Forgot to add that IME it can only work if the ski jump is originally caused by incorrectly shimming the neck.

A ski jump caused by the TR anchor for example won't be cured with just a simple shim.

Regards
Sam

 

[electracoyote]

Hi.



+1

Forgot to add that IME it can only work if the ski jump is originally caused by incorrectly shimming the neck.

A ski jump caused by the TR anchor for example won't be cured with just a simple shim.

Regards
Sam

Okay, I'll buy this with the (rather significant) caveat attached. Sounds like a long shot, but I can see it working. Under limited circumstances. In theory.

 

[T-Bird]

Hi.

Under limited circumstances.

When dealing with shoddy QC companies like ****** and the setup-ability challenged tinkerers, IME not so limited.

In theory.

And in practise.

Just because You haven't succeeded in doing that doesn't mean no one else has either.

Regards
Sam