Do I need a shim?

Discussion in 'Hardware, Setup & Repair [BG]' started by Riff Ranger, Feb 11, 2021.

  1. Riff Ranger

    Riff Ranger Supporting Member

    Mar 22, 2018
    Bigfoot Country
    I have a Squier Vintage Modified Precision Bass V with a Hipshot Kicka$$ bridge that just can’t quite get where I want it, and I suspect the setup has at least something to do with it. It came with a bit of sandpaper in the neck pocket that made intonating the lower strings impossible (thank you, TalkBass, for helping me figure that out). Now I can get the intonation close (and I will swap in some shorter screws to get it as close as possible; thank you, Hipshot, for sending them free of charge). I have a bit more relief and string height than recommended, but I have the bridge saddles really low (skinny string bottomed out) and even with the pickup lowered quite a bit, the strings regularly slap against the pole pieces and the thing sounds dull and distorted (in a bad way). Do I need to put a shim back in there? If so, how would I do that without reintroducing intonation problems? Thank you for any guidance you can provide. I want to love this bass!
  2. Reedt2000

    Reedt2000 Supporting Member

    Apr 26, 2017
    Central New Jersey
    A shim up against the body side of the pocket will let you adjust your action if without it the saddles are bottomed out. If the bass won't intonate, shorter screws might get you there, but if the bridge placement is bad you may just have to remove it, plug the holes, and reinstall it in the right place. As for the strings slapping the pickup poles, I suspect it may be as much a technique issue as it is a setup problem, though there's nothing wrong with lowering pickup height... to a point anyway.
    Riff Ranger likes this.
  3. Riff Ranger

    Riff Ranger Supporting Member

    Mar 22, 2018
    Bigfoot Country
    Thank you for the quick and helpful reply.

    I have the pickup further into the body than I have ever seen on a Precision, with just enough above the pickguard for anchoring my thumb. I do play hard whether using fingers or picks, and I tune GCGCF with standard gauge strings, so that may well contribute to the strings (mostly the .135, but also the .105) slapping the pole pieces, but that never happens on the four-string Precision with the same pickup and strings that I attack precisely the same ways; if anything, the bridge saddles are a bit high on that instrument. I do intend to go with .145/.110/.085/.065/.050 on the next set (adventures in nut filing, whee!).

    While I do suspect the bridge placement is a teensy bit too close to the neck, I’m confident that shorter screws will solve the minor intonation problems I still have. Ironically, that Low G intonated perfectly once I removed the sandpaper shim and went with a shorter screw; I just needed more of the shorter screws for other strings, which I now have.

    It sounds like I should get a better shim in there. I will try a note card on the body side of the pocket.
    Last edited: Feb 11, 2021
    Reedt2000 likes this.
  4. If you do put a shim back in don’t use sandpaper. Cut a length out of something like an old credit card about 1/2” width and length of the back of the pocket left to right and insert at back of pocket 524A257F-D7F1-492A-A604-EA0AD3753148.jpeg
    Riff Ranger and Squittolo like this.
  5. Riff Ranger

    Riff Ranger Supporting Member

    Mar 22, 2018
    Bigfoot Country
    By the time I saw this I had already gone ahead with this:

    … so, glad I seem to have gotten that about right.

    The change in string gauges, shimming, shorter intonation screws as necessary, and setting up with proper measuring tools rather than eyeballs alone seems to have done more good than harm. The .145 is now at worst 10 cents sharp at the 12th fret, with the other strings all really close to perfect. The saddle for the .050 remains bottomed out, but that was fine even before I did anything last night; the other saddles seem like they’re more in the “normal” range now. The more balanced strings feel better, and with a tiny bit of pickup height adjustment, I don’t have strings slapping against the pole pieces anymore. I will poke at things a bit more tonight, but I can live with things as I have them now.

    That said, as much as these instruments look alike, they still sound quite different from each other. The 5-string has more pronounced mids, while the 4-string has a much stronger top end. I have reduced the differences (other than additional materials associated with string count, obviously) down to just two things: the 4-string has a separate fingerboard while the 5 has a one-piece neck, and the 4-string has an alder body while the 5 has basswood. Electronics should be identical but I might try a different capacitor in the 5. It seems, though, that they just insist on different personalities!
  6. J_Bass

    J_Bass Supporting Member

    Feb 7, 2008
    Porto, Portugal
    I need a shim on one of my basses, too.

    Why doesn't the shim occupies the hole space of the neck pocket?

    Why is it only on the back?
    Won't it change the angle of the neck and cause fret noise on the upper frets?

    What material should the shim be? Wood? Plastic?
  7. Turnaround

    Turnaround Commercial User

    May 6, 2004
    Toronto Canada
    Independent Instrument Technician
    The point of a partial shim is to change the neck-to-body angle. It doesn’t cause buzzing in the upper frets- saddles too low causes that.
    Reedt2000 likes this.
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