Why 25" 28.6" or 30" for short scale basses?

Discussion in 'Luthier's Corner' started by Phil_S, Apr 10, 2021.

  1. Phil_S


    Apr 10, 2021
    Hello, I'm designing and building a short scale bass and was wondering why the scale lengths always seem to be the above measurements? Due to the confines of the wood I have I'm thinking of making the bass 28" (710mm) scale length - is there any weird string voodoo going to happen if I do that? Thanks
  2. dwizum


    Dec 21, 2018
    The only real constraint is finding strings that fit, and ideally where the wind on the thicker strings tapers between the nut and the string post.

    Early instrument designers were often driven by practicality and tradition. Leo tended to lean heavily on practicality, for instance. A 28.6" scale is essentially a 34" scale started at the 3rd fret. You can cut both fretboards with the same tooling.
    SBassman, J_Bass, MattZilla and 7 others like this.
  3. Phil_S


    Apr 10, 2021
    Of course! That makes total sense (3rd fret and tooling). SS Strings seem to be a whole other thread. Thanks, for the quick reply!
    jamro217 and dwizum like this.
  4. rudy4444


    Mar 13, 2012
    Central Illinois
    Dwizum said it all. :)

    In my limited experience with short scale design, practical experience, and a ton of searching out information I concluded that the 28.6" was based on practicality of adapting machining already used to produce other instruments in the firmly entrenched 34"scale length.

    Other manufacturers had long ago taken a different perspective on the scale length issue and adapted the 30" as a "short scale standard". The 30" scale length ends up being about as short as you can practically go for a 4 string bass and get an acceptably non-flabby E string with good tone. Any shorter than this and you find some string options start sounding pretty lifeless. It's a pretty good tip off that other manufacturers who had a long history of mass producing bass guitars opted for the 30" scale length.

    Players who have problems with the feel or tone of 30" scales sometimes opt for the 32" scale length, which provides better tonal options with the trade-off of higher string tension and longer fret to fret distances, although it's a worthwhile option to consider. Lots of players think it's worth the compromise.

    Sub-short scales in the 25" neighborhood push the limit even farther, and may be a result of many standard guitar players who are looking for scale lengths similar to what they are already familiar with.

    There's the other end of the spectrum, of course. Some players insist on 35" or 36" scale lengths and are fine with accepting the longer fret to fret distances and sometimes higher string tension to achieve more of the tone that they find to be better with the additional length.

    Strings are a deciding factor in choosing scale length from a practical perspective. There are some good lists of string choices for shorter scale lengths in the short scale sub-forums. I added a compiled list of strings that could be used on the Mikro 28.6" basses over in the "Mikro" sub-forum. Sme manufacturers go so far as to say their strings will not work on short scale bases if the windings are trapped against the string posts. That's a problem, and the string length choice can be affected a lot by how they anchor on the bridge end.

    Nothing to prevent you from using 28", although evaluate your design throughly to avoid the pitfalls in winding length for stock strings. You will be down in "flabby E String" territory, so that might factor into your design criteria and string choice option.
    Last edited: Apr 10, 2021
  5. Phil_S


    Apr 10, 2021
    Thanks @rudy4444 I've been reading through the SS sub-forum. Yep, now it is definitely coming down to strings first - then working around that within the parameters of the wood I have available (I've had it knocking around for ages and now is the time for it become an instrument). Thanks for the info on the E string - I'm going to calculate and redraw a few different scale length versions and see what fits. I'll share some progress on the appropriate thread once I get started! Thanks.
    bassrique and dwizum like this.
  6. dwizum


    Dec 21, 2018
    As I get older I start thinking more seriously about focusing on shorter scale lengths but I've only built a few to date.

    It's probably also worth mentioning the odd ball in the lineup: ukulele basses. 20 - 22" scale lengths, rubber strings, surprisingly big sound. Something to consider if you're after a very compact yet good sounding bass.
    Phil_S likes this.
  7. rudy4444


    Mar 13, 2012
    Central Illinois
    ...and the Ashbory bass, 18" scale and marketed since 1985 which pre-dates the Kala U-bass by many years. It's odd-ball, but popular enough to have it's very own sub-forum (HERE) on Talkbass.
    Last edited: Apr 10, 2021
    jamro217 and dwizum like this.
  8. LowWay

    LowWay It’s got 4 strings ‘cause they’re bigger! Supporting Member

    Dec 16, 2009
    W Mass
    yup I had one of those, but hated the rubber band strings. I love my heavily modded ubass now that you can get metal wound strings for them!

  9. A9X

    A9X Inactive

    Dec 27, 2003
    That makes perfect sense and the engineer in me would do the same. However, Alembic SS are 30.75" which is fret 2 on a 34.5" scale. I've seen this used (34.5") on a couple of boutique basses, but did anything use this scale back then? Just wondering as it makes little sense to me otherwise.
    Killing Floor likes this.
  10. dwizum


    Dec 21, 2018
    I have no idea where the Alembic scale length came from and I've never seen a 34.5" scale bass. Would be cool to find out how they came up with 30.75".
    jamro217 likes this.
  11. ficelles

    ficelles Inactive

    Feb 28, 2010
    Devon, England
    My short (or maybe medium) scale Dean fretless ABG is 32"... a scale that I find very comfortable. 28" scale is slightly shorter than 4/4 cello.
  12. micguy


    May 17, 2011
    There are a lot of different scales out there, but if you look at Fender products, their scales are based on one geometric progression. Take your 34 inch scale bass, and start measuring from the bridge to various frets. nut - 34 inches. 1st fret - 32 inches (Japan basses), second fret - a bit above 30 (Fender short scale basses). 3rd and 4th frets are baritone scales, 5th fret is 25.5 (full scale Fender guitars). 6th fret is 24 - one of Fender's shorter scales. 7th fret is 22.7 - another of their shorter guitar scales (Musicmasters). It's all one geometric progression - the machines that cut fret slots all have common numbers programmed into them, just lop a few frets off at one or the other end of the progression.
  13. A9X

    A9X Inactive

    Dec 27, 2003
    I think I still have a forum membership so I might just toddle over and ask. The 34.5" I'm sure was a smaller Euro builder, though Roscoe keeps coming to mind, though I can't find anything to confirm.
  14. Killing Floor

    Killing Floor Supporting Member

    Feb 7, 2020
    Austin, TX
    Duesenberg uses 30.7” for Starplayer basses.
  15. One thing to consider on scales well below 30” is that the notes in the upper register are very close together and can be harder to play. This is especially true for the Ukulele basses.
  16. steubig

    steubig Supporting Member

    Jul 17, 2001
    locustland, ca
    alembic probably used the guild starfire as the template for their stuff. it has 30.75.

    gibson ripper was 34.5, i believe.
    jamro217 likes this.
  17. Yes chopping off the first fret spacing on a 34 inch scale gives you 32.092 inches exactly and chopping of the first two gives you 30.291 inches exactly. I'd guess that those measurements would be close enough to 32 and 30 inches that no one would notice? (It's what I've always done and though I'd never made the link about all Fender scale lengths, I'm not surprised, Leo was a canny and smart operator.) ;)
  18. A9X

    A9X Inactive

    Dec 27, 2003
    Winner, winner, chicken dinner. Makes perfect sense now.

    "In 1969, Lesh was playing a stock Guild Starfire. Wickersham radically modified the instrument to include quadraphonic pickups (allowing the signal of each string to be sent to separate outputs) and active preamp circuits".

    Guild Starfire II (specs at bottom). Scale is 30.75"
    Last edited: Apr 10, 2021
  19. Bruce Johnson

    Bruce Johnson Gold Supporting Member Commercial User

    Feb 4, 2011
    Fillmore, CA
    Professional Luthier
    You guys have covered it well already. I'll just add a couple of notes:

    28" is a common size for baritone guitars, and there are some strings available. To me, 28.0" or 28.6" are good reasonable sizes to build a sub-scale bass suitable for airline overhead compartment travel. Keith Horne and I built the Marvin Mini-Basses at 28.0" scale.

    30.5" was a popular size for other-brand short scale basses in the '60's and '70's.

    Custom and hobby builders will often choose an instrument's scale length by the convenience of cutting down a common 34" or other slotted fingerboard. So you end up with 32.092" or 30.291". But for the bigger manufacturers, it's not really that useful to do that. They'll decide on the scale length for various design reasons, and reset the slotting machine for whatever scale length they choose. Almost all manufacturers, high end and low end, still use gang saws for cutting fret slots. Very fast and efficient and low-tech. And it's real simple to swap out the spindle for one set up for a different scale length.
    Phil_S likes this.
  20. rudy4444


    Mar 13, 2012
    Central Illinois
    Might as well give honorable mention to the Taylor GS Mini bass, with a 23-1/2" scale length.

    Taylor has a specialty strings made that are bronze wrapped nylon core strings that they say are responsible for the great tone.
    I have played one of these and they do sound quite nice, given the short scale length.

    Bottom line, there are a LOT of different scale lengths that have been or are currently being used. For any small shop or custom builder it's absolutely no problem to calculate fret positions and cut slots.

    As stated before, it's more important to make sure whatever scale length you settle on can be used with commercially available strings.
    Last edited: Apr 10, 2021
    TrustRod likes this.
  21. 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.

    May 18, 2022

Share This Page