Shimming a bridge???

Discussion in 'Hardware, Setup & Repair [BG]' started by PBassTX, Jan 25, 2013.


  1. PBassTX

    PBassTX Supporting Member

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    So I am converting a MIM Fretless Jazz to a fretted Jazz... but I really wanted to use an Aerodyne Jazz neck and a high mass bridge (either the Babicz or Hipshot Type A). The problem is neither of those bridges are high enough. I have never had that problem before. I have had bridges that don't go down low enough so I shimmed the neck, but I have never had to shim a bridge....is it even possible? If so what should I use?

    Thanks in advance for the help.

    I am about two seconds away from putting the fretless back together and selling it...and buying a Jazz. But I am looking for something very specific.
     
  2. mech

    mech

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    I'd use a brass or aluminum plate. Trace the base plate pattern on the stock and it'd be easy to fabricate with hand tools. Depending on the thickness of the shim needed, you may need some slightly longer screws.

    mech
     
  3. FunkMetalBass

    FunkMetalBass

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    I'd take a look at the pickup height and gauge from there. On some of my basses, the pickups don't go high enough, in which case the solution is actually to sand down the neck/deepen the neck pocket.

    If it is a bridge shim, I too would recommend having one made from the same metal as the bridge.
     
  4. bassclef112

    bassclef112 Supporting Member

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    Just to make you aware - the Babicz is not a high mass bridge. Actually it weighs in about the same as a standard Fender bent plate. I have a couple of both and the Babicz is very deceptive. It looks like it should weigh a lot. It's great bridge, but if you want high mass go with the Hipshot A in brass.

    When I mounted a Babicz on one of my parts Jazz basses it required a shim. Rather than use metal my tech made one from a piece of thin rosewood stock (about 1/8" thick) he had and it works great.
     

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  6. PBassTX

    PBassTX Supporting Member

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    Thanks for the suggestion. I guess I assumed that "full contact" meant high mass... not sure why I did now that I think about it... Anyway. I already have the hipshot A in brass. I will try the Rosewood stock before I try something metal.
     
  7. Bobster

    Bobster

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    I agree with funkmetalbass. You need to sand the neck heel, or route the pocket a bit.

    All the best,

    Bob
     
  8. PBassTX

    PBassTX Supporting Member

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    The thing I am concerned about is we are not talking about a small amount here... The Hipshot A bridge I put on it has 3/8" screws to adjust the action height... I took them as high as I could and it's still not even close. Still A LOT of fret buzz on open strings. I would sand the neck heel if it just needed 1/16th to 1/8th of an inch, but 1/2" is a bunch. I can't figure this one out. The Aerodyne neck does appear to be a little thicker than the fretless neck, then you add the height of the fret, but it's still does not add up to 1/2".

    Of course raising the string at the bridge 1/2" doesn't raise the string at the 1st fret 1/2"....
     
  9. testing1two

    testing1two Gold Supporting Member

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    If you are off by 1/2" or even 1/4" then I recommend you go with your previous instinct of putting the fretless back together and selling it. Clearly the Aerodyne neck is not meant for an MIM body.
     
  10. Turnaround

    Turnaround

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    Neck shims can work both ways. If your bridge won't go low enough, you put a shim at the bridge end of the pocket. To deal with a bridge that won't go high enough, put the shim at the other end of the pocket.
     
  11. Scott in Dallas

    Scott in Dallas

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    Yep. I can't think of a need to mess with the bridge when you can change the neck angle in either direction.
     
  12. Jazz Ad

    Jazz Ad Mi la ré sol Gold Supporting Member

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    +1
     
  13. JoeWPgh

    JoeWPgh

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    The neck shim is the way to go. I prefer to create a 'ramp' out of 1" making tape. 3 layers, 2 layers, 1 layer, no layer. I suspect this formula would solve your problem. If you still need a bit more, add a layer to each step.
     
  14. PBassTX

    PBassTX Supporting Member

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    thanks for all the great info....
     
  15. jeffcarano

    jeffcarano

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    Babicz now offers "High Profile Saddles" for their bridges so that shimming may not be necessary. The saddles have a higher profile with more contact where the string meets the saddle....this in turn allows for a higher string height adjustment range. Babicz offers these saddles at no charge to Babicz Full Contact Bridge owners....just contact them through their website and they will send a set out to you.
     
  16. Hopkins

    Hopkins Supporting Member

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    I would rather shim the bridge than put a shim at the outer end of the neck pocket, for the simple fact that on that end you can see the shim (or at least a gap in the pocket)

    I would sand down the heal of the neck. Get some 60 or 80 grit sticky back sand paper and stick it to a flat surface, and run the heal of the neck over it holding it dead flat. It should only take about 10 minutes to remove enough material to make it work. You wont have to remove nearly as much material as you think, less than 1/16 will probably do it.

    I have heard complaints about the Gotoh 201 bridge not having low enough action and people having to shim their neck to compensate. In your case it could possibly be exactly what to need to make your project work with no modification at all.
     
  17. Scott in Dallas

    Scott in Dallas

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    Usually the amount shimmed is not more than the thickness of a business card, and the geometry allows for a much smaller shim at the neck joint than at the bridge. You'd notice a thick piece under the bridge before you'd notice a gap in the back of the instrument IMHO.

    Hopkins' suggestion would be much prettier, but I throw necks around to different instruments too often to have the courage to do that.
     
  18. DWBass

    DWBass The Funkfather Supporting Member

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    My custom bass has a recessed bridge due to not being able to get the action like I wanted. A lot of basses have recessed bridges though. But you're talking about 'raising' the bridge?? Can't get high enough? I think I would route a deeper neck pocket before raising the bridge.
     
  19. unclebass

    unclebass

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    Working on a bass that was purchased at a pawn shop. After adjusting truss rod, had to set the saddles so high, the set screws were falling out the bottom of the saddles. Decided to shim neck. When I removed the neck, I discovered that someone had already shimmed it with a doubled over business card at the heel of the neck. Removed it and readjusted, now top of set screws are at the top of the saddles. Made over 1/4 inch difference in bridge height. Can't figure why that was done to begin with, but it plays great and the action and pickups are at a sensible level.
     

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