Weather Changes Affecting Action?

Discussion in 'Hardware, Setup & Repair [BG]' started by Coltrane21, Dec 7, 2012.


  1. Coltrane21

    Coltrane21

    Joined:
    Jul 3, 2012
    Location:
    San Francisco
    Hi All -

    This is admittedly my first winter as a bass player, so please forgive my ignorance..

    Can the change in weather affect an instrument's action? It's just started to be cold on a regular basis where I live (Northern CA. - not that cold, but still a change).

    Was taking a close look at the action on both of my Ibanez basses tonight since they didn't feel quite right. The action is very low at the nut, but pretty high towards the bridge. So much so that on one of them, the string rings when I fret a note (creates a very dissonant double stop - has never happened before today).

    I think today may be the coldest of the year so far, and I assume the wood is reacting. Is this just a case of normal adjustments needed?

    If so - any good resources available to learn to do this on my own? I've seen the setup guide sticky, but that doesn't speak to Ibanez and I'm concerned I'll damage something. Although from what I understand I should be OK as long as I don't damage the 'trust' rod. :)

    Thanks all!
  2. JamesGoodall

    JamesGoodall

    Joined:
    Aug 29, 2011
    Location:
    Dallas
    This happens seasonally. You'll just need a slight adjustment of your truss rod. Depending on your bass it will either be under a cover on your headstock or at the end of your neck.
    To adjust it you'll need an Allen wrench, I'm not sure what size, and you'll crank it a little under a quarter turn in one direction, depending on what way your neck is bowing. To see that just look down your fret board from the headstock. Ideally you'll want a slight inward bow from the strings, so your bass may either have too much of a bow, or its bending in the opposite direction.
    I can't remember which direction to turn it for which way the neck is bowing off the top of my head, but a quick search on Google or TB should tell you fairly quick.
    One last thing! Do not crank it more than a quarter turn at a time. Adjust it once, then wait at least 24 hours or you risk overcompensating and potentially damaging your neck permanently. If it still is a little off, continue in the same manner with 1/8 turns every 6 hours or so.

    Hope this helps!
  3. seanm

    seanm I'd kill for a Nobel Peace Prize! Supporting Member

    Joined:
    Feb 19, 2004
    Location:
    Ottawa, Canada
    San Francisco cold? I laugh in your general direction!

    Just kidding. How old is the bass? It could also be just settling in.
  4. greggster59

    greggster59 Supporting Member

    Joined:
    Oct 31, 2006
    Location:
    New Jersey
    Also, pay attention to the humidity levels where you keep your bass. In the winter the air tends to be drier due to indoor heating and colder outside air.
    If your bass has a sealed finish than it won't be as sensitive to the changes. But, it's not a bad idea to keep your bass in a case with a guitar humidifier such as an Oasis Humidifier.

    Wood likes it close to 50% RH.
  5. Register to disable this ad
  6. kreider204

    kreider204

    Joined:
    Nov 29, 2008
    Location:
    WI, USA
    Didn't Mark Twain say something like "The coldest winter I ever spent was the summer I spent in San Francisco"? :)
  7. Mystic Michael

    Mystic Michael Hip No Ties Supporting Member

    Joined:
    Apr 1, 2004
    Location:
    New York, NY
    It's called "backbow" (the headstock flexes backward, the fretboard flexes forward, the playing action gets lower, and the strings ring sharp), and it happens - if it happens - whenever air humidity goes way up.

    To remedy, put some more relief into the neck: Turn the truss rod (not the "trust rod") no more than a quarter-turn clockwise (as one sights down the length of the neck from the headstock). Easy does it. It shouldn't take more than that - usually.

    During the time of the year when the weather turns warm & dry, you may encounter the opposite problem: "frontbow" (i.e. the headstock flexes forward, the fretboard flexes backward, the playing action gets higher, and the strings ring flat). Take the excess relief out of the neck. Simply turn the truss rod back counter-clockwise - again no more than a quarter-turn at a time. That should do it. :meh:

    MM
  8. JamesGoodall

    JamesGoodall

    Joined:
    Aug 29, 2011
    Location:
    Dallas
    ^much better than my jumbled mess of words
  9. JustDavid

    JustDavid

    Joined:
    Oct 21, 2008
    Location:
    Halifax, NS, Canada
    To my view, seasonal changes in environmental humidity & temperature cause changes to only the neck relief.

    Environmental changes shouldn't change nut slot height nor bridge saddle height. I'd presume the same strings are used. All that's left that impacts action is neck relief.

    This should be well covered in the Stickies & links, but fret the neck at the first & last frets (this lets that string act as a straightedge, & using a capo really helps doing this) & measure the gap between the bottom of that string & the top of the 9th fret. This gap should be roughly between the thickness of a business card & a credit card.

    The neck relief can be changed by:
    - string tension (up-tuning, down-tuning, new strings with a different tension)
    - truss rod tension
    - neck wood 'tension'.
    Truss rod tension is an easy adjustment on well-designed instruments. String tension is a variable, but not in this situation. Neck wood 'tension' (or flexibility, or your term of choice) can be controlled by controlling humidity/temperature, but this can be awkward & costly; very costly when compared to the cost of a hex key & a set of feeler gauges.

    If neck relief was good & now is bad then something has changed; the most common causes are different string tension and different neck wood tension.

    If your neck relief is too large, this means the strings are now pulling too hard. To counteract excess neck relief, tighten the truss rod. I recommend a newbie measure & note the neck relief, adjust the rod 1/4 turn, again measure neck relief &, if desired, repeat this 'measure & 1/4 turn' procedure.
  10. Coltrane21

    Coltrane21

    Joined:
    Jul 3, 2012
    Location:
    San Francisco
    Thanks everyone, this is very helpful. I'm slightly confused on back bow vs. front bow. On the more affected instrument, it appears that the strings are bowing outward. According to the above, shouldn't this be the opposite based on the cold temperatures? I'm thinking that the warm temperatures inside might have an effect as well.

    At any rate, here is what I'm seeing:

    Strings bowed outwards
    Neck slightly bowed away from the strings

    Based on this, it seems that I need to turn the truss rod 1/4 turn counter-clockwise to remove some of the relief. Does this sound correct?

    Oh, and to clarify, 'trust' rod was my poor attempt at a joke. Saw it in someone's sig one day and it cracked me up for some reason. :)
  11. JustDavid

    JustDavid

    Joined:
    Oct 21, 2008
    Location:
    Halifax, NS, Canada
    Your strings likely aren't bowing outwards ;)

    I think you will find that you want to turn the truss rod clockwise, to tighten it's nut & increase it's tension. But adjusting in small steps & measuring the effect of your actions will tell you if your adjustments are doing the opposite of what you want.

    I'd call your symptom front-bow not back-bow.

    There's a great deal of good info in http://www.talkbass.com/forum/f18/all-basic-setup-questions-answered-here-125382/
  12. Coltrane21

    Coltrane21

    Joined:
    Jul 3, 2012
    Location:
    San Francisco
    I've made a couple (very careful) adjustments to the rod this week (essentially amounting to a 1/2 turn clockwise), but that doesn't seem to be helping what I can best describe as the isosceles triangle formed between the strings at the nut, strings at the bridge, and the fretboard. The rod doesn't seem to want to move clockwise anymore, and I'm certainly not going to force it.

    The issue is basically the same between both of my Ibanez basses (both less than 1 year old); they both played well as recently as a couple of weeks ago.

    Should the next step be adjusting the bridge saddle? I've read the guides in the sticky and a couple of them speak to a full setup when the seasons change, but do not explicitly mention weather changes necessitating a change to anything other than the neck relief.

    Sort of at a loss here, so any further help is appreciated!

    Thanks!
  13. JustDavid

    JustDavid

    Joined:
    Oct 21, 2008
    Location:
    Halifax, NS, Canada
    What were the neck relief measurements before adjusting & after the 1/2 CW adjustment?
  14. Coltrane21

    Coltrane21

    Joined:
    Jul 3, 2012
    Location:
    San Francisco
    I must admit .. I did not measure. Thought I could eyeball it. I'll be taking a more scientific approach going forward.
  15. charliebrown

    charliebrown

    Joined:
    Dec 13, 2012
    Location:
    N. California
    Happens to my guitars every extreme seasonal change. Just picked up a used Jazz Bass and changed the light gauge roundwounds to flatwounds (45-105). Gave myself a double wammy with more tension from the new strings and the colder weather. It took me tightening the truss rod one whole turn over the course of 3 days to get it set so I have .012 relief at the 8th fret with a capo on the first fret and holding the E string at the last fret. Did the final adjusting today; will check in the morning and see if it stablizes. I will say it plays like a dream now. And I always give the truss rod adjustment at least 24 hours for the neck to settle in.

    For someone who has never done this before, be very cautious when tightening as opposed to loosening. Unlike some, I always loosen my strings before I tighten the truss rod on a bass...just lots of tension compared to a guitar.
  16. charliebrown

    charliebrown

    Joined:
    Dec 13, 2012
    Location:
    N. California
    That's why I moved :smug:
  17. Salamenster

    Salamenster

    Joined:
    Apr 8, 2012
    Location:
    European Mainland
    I have the same problem, but I feel that the action has gone up! (More distance between string/fret) and now I have this irritating fretbuzz at the 15th and 16th of the two middle strings (and a bit on the other two). Is this also a truss rod issue or could it be the fact that the strings are quite old?

    Additional info: Using the 'capo 1st fret, press last fret and try with credit card'-method: The credit falls to the ground. Would a truss rod adjustment be necessary? If I do (and the room I keep my instruments is quite cold), would I get opposite effect gigging in lets say an indoor-bar?
  18. johnson79

    johnson79

    Joined:
    Jan 8, 2010
    Location:
    East Petersburg PA
    After moving from PA to CO and not playing my G&L much it had some crazy high action. When I sold it it took a few turns to get it low. I didn't dare attempt that myself, I left it to the shop I sold it to.

    If you're hesitant, take it to a good repair person and ask to watch while they fix it.
  19. Salamenster

    Salamenster

    Joined:
    Apr 8, 2012
    Location:
    European Mainland
    Bump for my post above. ^^
  20. freeridden

    freeridden

    Joined:
    Dec 1, 2010
    Sorry if I seem confused. I checked the Fender specs and the first/last fret test. My action is high because I kept getting a clanging sound from the 1st to 4th frets on my B and E strings (mostly). When I do the test, I don't have any room under the 8th fret. It's cold as hell here, so I'm assuming the cold weather has affected my relief. If the truss rod is near the body and not the headstock, then which way should I adjust the truss rod?
  21. Pilgrim

    Pilgrim Supporting Member

    Joined:
    Jul 8, 2004
    Location:
    Fort Collins, Colorado
    It's probably due more to change in humidity than temperature. No big deal, but if you live in an air conditioned home, adding a humidifier to the room where the bass is kept and maintaining humidity at a steady level throughout the year will minimize any changes in the neck.

Share This Page