“Cheating” the scale length

Discussion in 'Luthier's Corner [DB]' started by zootsaxes, Jan 17, 2022.


  1. zootsaxes

    zootsaxes Supporting Member Commercial User

    Mar 6, 2015
    Memphis TN
    I am wondering what everyone's philosophy is in regard to adjusting the bridge up to 1/2" in either direction (up or down) to get a desired scale length. Say, if you had a customer with a 42" bass that wished it was 41.5" or the other way around - not big changes (1"+) that would require a false nut, etc.

    Does it haphazardly throw off the resonant magic of whole bass design, or is it saavy so long as you also adjust the soundpost to compensate?

    Thanks, gang!
     
  2. dhergert

    dhergert Gold Supporting Member

    Jan 17, 2018
    Blue Zone, California
    I'm sure some people do it, but for me, the bridge adjustment is purely for setting action. To me that's more important than 1/2" shorter or longer scale length.
     
  3. zootsaxes

    zootsaxes Supporting Member Commercial User

    Mar 6, 2015
    Memphis TN
    No, I'm sorry - I wasn't being clear. I don't mean raising or lowering the height of the bridge, I meant physically moving it up or down on the top of the bass - like, as in not necessary lined up with the F hole notches...
     
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  4. dhergert

    dhergert Gold Supporting Member

    Jan 17, 2018
    Blue Zone, California
    Ahhhh.

    That's different. Ok, now I'm interested in hearing expert opinions... Thanks for the further explanation!
     
  5. Eric Hochberg

    Eric Hochberg

    Jul 7, 2004
    Chicago
    I cheated the bridge up 1/2" on an old bass with no ill effects on sound. It will probably change the
    heel stop pitch though. The soundpost may have to follow, too.
     
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  6. Greg Clinkingbeard

    Greg Clinkingbeard Commercial User

    Apr 4, 2005
    Kansas City area
    Black Dog Bass Works
    There’s nothing magical about that spot between the notches so move it if you want. The only caveat might be to check for a soundpost patch inside in the event the post follows along on the trip. The D note on the G string is 1/3 of the playing length so if the bridge moves even one inch it’s probably not a big deal. The D will move less than 3/8”.
     
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  7. The effects of shortening the string length by either or both a false nut and moving the bridge were discussed in the thread "False Nut Question" started by dhm on October 2 2021. From this lifting the bridge alone an inch would move the octave G 1/2" lower, D 1/3", C 1/4" ,etc, and have the least effect on the lowest positions. Think about the current position of the index finger on D relative the thumb opposing at the base of the neck. I trust the setting of my hand relative to my thumb for intonation in Simandl IV and V Positions. Moving the bridge up is a lot less risky than shortening the neck artificially with a false nut and is not permanent.
     
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  8. zootsaxes

    zootsaxes Supporting Member Commercial User

    Mar 6, 2015
    Memphis TN
    Thanks guys, this is exactly what I was wondering. It's a purely hypothetical question because I dare not touch the expert setup on my two primary basses but am actively seeking out a busted up longer-scale King to experiment with learning how to bring down the scale to my preferred 41.25". I appreciate ya'lls wisdom and guidance as always. -Jeremy
     
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  9. stefaniw80401

    stefaniw80401 Supporting Member

    May 18, 2004
    Evergreen, Colorado
    To @dhergert post #2, if you have a fixed bridge - w/o adjusters - you CAN still raise and lower the string action by moving the bridge north and south respectively.
     
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  10. dhergert

    dhergert Gold Supporting Member

    Jan 17, 2018
    Blue Zone, California
    Yes, and thank you...

    I was just totally mixed up on how this movement was happening. @zootsaxes straightened me out and I've been enjoying reading all the subsequent responses.

    Question, and probably a dumb one. Does the word mensure mean the same as scale length in this context?
     
  11. Yes, absolutely.
     
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  12. I think King Mortones have a string length that's around 43", correct? If you cheat the bridge to make it 41.25", I think the locations of the notes might get pretty wonky. Then again, it might be enough to make an Eb neck into a D neck...
     
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  13. zootsaxes

    zootsaxes Supporting Member Commercial User

    Mar 6, 2015
    Memphis TN
    Yeah, that's the plan. I've got an American Standard that the Cincinatti Bass Cellar folks cut down to a very comfortable 42" D neck ... I know it's an incredibly difficult job for an amateur luthier (as per the Traeger book), but I intend to try to copy every facet of what they did - angle of the cut, CF rods, thick new fingerboard, etc. I won't know until I get into one about how and where to put stuff to make the D stop work right, but I'm looking forward to trying.
     
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  14. Tread carefully, guys. Moving the bridge up would make an E flat neck worse, wouldn't it? A false nut or replacement neck would move an E flat neck towards a D neck (with great care and forethought)?
     
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  15. GretschWretch

    GretschWretch Supporting Member

    Dec 27, 2013
    East Central Alabama
    But it's an easily reversible mod. The bridge can always be moved back.
     
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  16. Greg Clinkingbeard

    Greg Clinkingbeard Commercial User

    Apr 4, 2005
    Kansas City area
    Black Dog Bass Works
    I understand the bias, but ‘worse’? Geez. Moving the bridge 1/2” will move it less than 3/16” and the player might just get used to it.
     
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  17. Actually, Greg, I am more worried by the alternatives of shortening the neck alone or making a false nut unless the bass already has a long (index finger on E flat) neck. I recently bought a nice sounding inexpensive 60yo 4/4 German bass whose mensure had been shortened 1 and 1/2" by a new neck graft that moved the D an inch higher towards the bridge. The now uncomfortable D flat neck has made Simandl IV and V Positions very awkward. I thought that I could adjust but it's bugging me a lot and I will have to pass it on but before I do so I will try lifting the bridge 2 inches. This should drop the D back about 2/3". The original 43 1/2" mensure will end up about 40 ". An interesting experiment for my Bel Canto strings that is obviously easily reversed.
     
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  18. Greg Clinkingbeard

    Greg Clinkingbeard Commercial User

    Apr 4, 2005
    Kansas City area
    Black Dog Bass Works
    Old basses often come with a bucket of compromises.
     
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  19. 16fuss

    16fuss

    Apr 25, 2005
    ... so does whole life.
     
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  20. Primary

    Primary TB Assistant

    Here are some related products that TB members are talking about. Clicking on a product will take you to TB’s partner, Primary, where you can find links to TB discussions about these products.

     
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