What Exactly Is Neck Shimming?

[bakerman]

Originally Posted by JeffWiredBeck24

Man, I completely forgot about this thread. I never got around to seeing if my guitar has a shim or not, but I've been having some problems with feel and playability and Dee said in an above post that a shim can be used to fix problems in these fields. My neck feels a bit, stiff right now. The action isn't ridiculously low but I'm still getting A LOT of buzz on the bass strings. Bending below the seventh fret feels stiff and rough and it just doesn't feel as nice as it used to.

Can anybody tell me what, where, how, and in what direction I should put a shim? Size of the shim? Business card, string packs, etc.?

Thanks a lot.

What you've described aren't things that neck shimming is a direct solution for. It's really just a coarse adjustment to let you keep the bridge posts & pickups at a certain height (if that's desired) if you're getting away from it during the setup process. For example, you'd do the bridge-edge shimming of the pocket when the posts are screwed in all the way and you're trying to lower the action even further.

If you have buzz on the low strings, look into truss rod and bridge post adjustments first, as well as making sure the neck isn't warped and frets are level. If you find the posts need to be too high or low or one ends up higher than the other, then proper shimming would let you get them back to a more normal-looking position. Except when you run out of post range, you should be able to fix the problem before shimming, because it will only be that good after shimming. You'll just have the bridge back from a strange height/angle.

A shim probably won't make bending feel any easier. Action is the only thing it can change that could possibly influence how bends feel, and there's no difference in feel getting the action down to X amount with a shim vs. bridge post adjustment.

[Drew]

Originally Posted by judasbane

as jax suggested, you'll either have to raise or lower the bridge height depending how and if you change the angle...
lowering the bridge doesn't necessarily constitute low-action although it is part of the equation. It does affect how "easier" it is to play the guitar dependent on the strings, tuning, fretwire, and eventually, proper setup. Plus hitting rock bottom on the bridge height hinders trem-pullups
The Non-AANJ Ibby's I have always had a shim similar to the 2nd pic... if your guitar already has one, add a shim with the thickness of a folded business card.

Reg

Excellent diagrams, dude.

I have yet to play a stock Ibanez that hasn't benefitted from at least a slight increase in neck angle. I have no idea why, and I suppose this is personal taste, but Ibanez seems to ship with a little less neck angle than I really like. Every Ibby I've ever owned over the years has at some point in its life had the neck pulled, a guitar pick or business card slice stuck in the back of the neck cavity, and the bridge raised slightly, and they've all played better for it.

[Drew]

Originally Posted by bakerman

A shim probably won't make bending feel any easier. Action is the only thing it can change that could possibly influence how bends feel, and there's no difference in feel getting the action down to X amount with a shim vs. bridge post adjustment.

98% true. I'm just going to nit-pick here for a moment, but I actually (personally) find bending easier with higher action. I think it's a question of leverage - with higher action it's a little easier to "get under" the string, so I can excert force on it more cleanly. With super-low action and, especially, medium or light frets, the string is so close to the fretboard that you're kind of pushing at an angle, so not only is it tough to keep a "grip" on the string, you also have to push harder since you're only applying pressure obliquely.

This could easily be a factor of technique though.

[waylay00]

Originally Posted by Drew

98% true. I'm just going to nit-pick here for a moment, but I actually (personally) find bending easier with higher action. I think it's a question of leverage - with higher action it's a little easier to "get under" the string, so I can excert force on it more cleanly. With super-low action and, especially, medium or light frets, the string is so close to the fretboard that you're kind of pushing at an angle, so not only is it tough to keep a "grip" on the string, you also have to push harder since you're only applying pressure obliquely.

This could easily be a factor of technique though.

I agree with this. I used to play with low action (1.2mm-1.5mm at twelfth fret), but after experimenting with action a little bit higher (1.5mm-2.0mm), I find that there are so many benefits. It's easier to get nice vibrato, better sounding bends, and not to mention, the sound of the guitar is so much thicker. Plus, you don't have to maintain your guitar as much and make adjustments at every temperature change. And if Yngwie, Vai, Eric Johnson, Steve Morse, and others can play with action a little higher, then I think I can live with it too.

Now I'm not saying get it up to SRV heights, but you might be surprised if you raise your action a few tenths of a millimeter.

[JeffWiredBeck24]

Yeah, I raised my action about 1.8 mm at the 12th fret and it's an overall improvement, but the guitar still feels "stiff". A shim couldn't remedy this? Any adjustments here and there that can?

EDIT: Drew, do you place the shim toward the bridge or away from the bridge?

[bakerman]

Originally Posted by JeffWiredBeck24

Yeah, I raised my action about 1.8 mm at the 12th fret and it's an overall improvement, but the guitar still feels "stiff". A shim couldn't remedy this? Any adjustments here and there that can?

EDIT: Drew, do you place the shim toward the bridge or away from the bridge?

There are only so many things a guitar can do to make it harder to push a string out of line. Rough/gunky frets, old strings, action less than ideal, grip/leverage provided by the neck shape and fret height.

Saying a guitar feels stiff is such a vauge description that there's no way to tell if a shim is needed at all. If you feel it's the action height (all a shim changes--you're just moving the neck relative to the body instead of bridge relative to body) that makes the guitar feel stiff, try adjusting the bridge height first. A shim is the answer to tremolo posts reaching or nearing their limit (accompanied by limited pull-up range) or the bridge being at another less than ideal position, like too high for comfortable playing or with posts at unequal heights. The shim itself does nothing else for the feel of your fingers on the string, frets and neck.

[Drew]

Originally Posted by JeffWiredBeck24

EDIT: Drew, do you place the shim toward the bridge or away from the bridge?

Depends on what I'm trying to do. If there isn't as much neck angle as I like, I'll put a shim at the back of the neck cavity, towards the bridge. Too much, and I'll shim the front of the cavity away from the bridge, though I've never had to do that to an Ibby.

Think for a second though on what changing the neck angle will do - it will adjust how high or how low the bridge will have to sit against the body if you want the same angle. From the perspective of the strings, then, a neck shim doesn't really change anything. Height changes will only change the angle of the trem springs in the cavity relative to the guitar, but not how far they have to stretch to reach equiliberum, and how far they stretch is what would change percieved "stiffness."

How many springs are you running in the control cavity? The more springs you use, the stiffer the guitar will feel, I've heard, so if you have 4, see if you can adjust the claw screws to provide enough tension with three. If you have three (as you probably do if you string 9-42), see if you can get away with two. Alternate,y I've heard guys say this formation: \|/ provides a less stiff feel than this: |||. worth a try, though I can't personally vouch for it.

EDIT - Bakerman, that's not quite true on a floating trem. Guitars with floating bridges will feel a little slinkier than fixed bridge guitars, because as you bend, the total string tension will increase and the equiliberum between string tension and the offsetting spring tension will change, so the bridge itself will shift a little (causing the rest of the strings to go slightly flat and compound bends to sound like crap, lol). The amount the bridge shifts will be dependant on how "stiff" the springs are - the more they're "willing" to stretch, the more the strings will feel slinky and stretchy. If they don't want to stretch at all, though, then they'll provide way more resistance and will move shorter distances, and the guitar will feel tighter. thus, changing the resistance to stretching of the springs will make a guitar feel more or less tight.

[bakerman]

Originally Posted by Drew

EDIT - Bakerman, that's not quite true on a floating trem. Guitars with floating bridges will feel a little slinkier than fixed bridge guitars, because as you bend, the total string tension will increase and the equiliberum between string tension and the offsetting spring tension will change, so the bridge itself will shift a little (causing the rest of the strings to go slightly flat and compound bends to sound like crap, lol). The amount the bridge shifts will be dependant on how "stiff" the springs are - the more they're "willing" to stretch, the more the strings will feel slinky and stretchy. If they don't want to stretch at all, though, then they'll provide way more resistance and will move shorter distances, and the guitar will feel tighter. thus, changing the resistance to stretching of the springs will make a guitar feel more or less tight.

I realize that, and shouldn't have made it seem like like that was a complete list. I left it out because I think there's further explanation required on the floating = slinkier thing: Even though it's easier to push the string a certain physical distance with a floating bridge, it takes more distance and force to reach a target pitch. Judging by feel alone or feel & eyes it will feel easier to bend, but once ears come into play and you're bending by specific intervals, I think the guitar with more resistant springs or fixed bridge will seem easier to bend on. I definitely notice that when switching a particular guitar's setup from floating to dive-only.

[JeffWiredBeck24]

Originally Posted by Drew

How many springs are you running in the control cavity? The more springs you use, the stiffer the guitar will feel, I've heard, so if you have 4, see if you can adjust the claw screws to provide enough tension with three. If you have three (as you probably do if you string 9-42), see if you can get away with two. Alternate,y I've heard guys say this formation: \|/ provides a less stiff feel than this: |||. worth a try, though I can't personally vouch for it.

I string 9.5-44 and have three springs in a ||| formation. Unfortunately, I can't try the \|/ formation because I have a Tremol-No installed.

[bakerman]

Regarding arrow vs. parallel spring setups: The difference will probably be too small to be perceivable during normal playing & bar use. Here's a test I mentioned in another thread a while ago:

I've compared 3 springs straight vs. arrow using enough weight taped to the bar for approx. 1 whole step dive on the 3rd (with guitar face up and the bar in the same position each time). The arrow setup resulted in about 3 cents more drop iirc.

[Drew]

Sorry bakerman, just being anal here.

I've actually had the opposite impression though, that bending feels a bit stiffer when I lock down my Tremol-no. Weird.

Jeff - maybe see if you can get away with two springs tightened way up, instead of three?

[bakerman]

Originally Posted by Drew

I've actually had the opposite impression though, that bending feels a bit stiffer when I lock down my Tremol-no. Weird.

If you haven't done a quick back-to-back test, see if you have any thoughts on D-string 1.5-step bends, or whatever you'd consider a very difficult bend on any string, at a specific fret with fixed vs. floating setup. That's when I notice the difference the most--the floating setup will shift things from the "really tough" category to "nearly impossible", and I have to palm the bridge or pull up on the bar to hit the target pitch as consistently as on a fixed bridge.

[Drew]

I haven't since I installed the thing... Tonight, if I get a chance, but I don't spend as much time online on the weekends as I do from work, so you might not get an answer before Monday.

[Drew]

Hmm, I lied. Here I am.

Well, yes and no. For starters, I string 10-68 on my Universe, so we're talking pretty heavy strings. Bending actually felt pretty similar on both - I started on a step and a half bend, and then for kicks did a two step bend, D to F# on the high B, 15th fret. It actually felt pretty similar in terms of tension, but I definitely had to "push" the string further unlocked, and ended up with my fingers a little under the G string.

Heh.

Anyway, I suppose all in all that makes sense - there's a little more intial give, but you have to cover a further distance.