Ibanez BTB twin truss rods- HOW DO YOU ADJUST????

Discussion in 'Hardware, Setup & Repair [BG]' started by vindibona1, Feb 27, 2018.

  1. I've got a bunch of guitars and 1 bass. All have single truss rods and I have no difficulty adjusting neck relief with any of them. Enter my new 5 string Ibanez BTB675 with twin truss rods!

    I've never seen dual truss rods before and didn't even know they existed. The neck relief seems to be in spec a the moment, but this being Chicago on the cusp of Spring (it was 61° today) an adjustment is coming soon, particularly as I am planning on changing strings soon. I just want to get it right.

    So how do you approach adjusting two truss rods in the same neck??? No instructions to be found with my interwebz search. Is there a link to any kind of instructional video or blog? If not, can someone provide a guide to twin TR's?

    Thanks in advance
  2. Ok... I did some more research and found a thread that pointed me to the Jerzy Drozd setup guide. So in reading this, he states there are two "styles" of dual truss rods, but I can't find out which style my bass has. You'd think some of this information would be available on Ibanez's website. Can anyone tell me what kind of truss rod system is in the BTB675? Is it a parallel system or a Diagonal Double Truss-Rod System?
  3. 96tbird

    96tbird PLEASE STAND BY

    I would work on the B side first since it needs more relief. Set it up first then work on the high side so it has similar or slightly less relief.

    I think Jerzy’s reference to dual rod means a dual action rod NOT two separate rods.
  4. Yes. The short, oversimplified version would be that, when there are two truss rods just treat the bass and treble sides “separately” and adjust the relief as needed.
  5. Turnaround

    Turnaround Commercial User

    May 6, 2004
    Toronto Canada
    Independent Instrument Technician
    I advocate adjusting both rods the same amount.

    Some will say that two rods allow you to adjust for different amounts of relief on each side of the neck. IMO an imbalance in the tension of the two rods will have a tendency to introduce a twist or crook in the neck.
    Lenny JG, Hopkins, wcriley and 5 others like this.
  6. DiabolusInMusic

    DiabolusInMusic Functionless Art is Merely Tolerated Vandalism

    Ibanez runs their rods parallel. Adjust each rod an equal amount.
    Spin Doctor and Paulabass like this.
  7. I can see how it is possible to assume his reference is to dual action, but he actually addresses both. See page 41 of his guide. Mercifully someone from the forum posted the link back in 2012.

    I'm inclined to agree with you guys. Jerzy actually advocates using a torque wrench to get even tension. Short of having a torque wrench I would assume that if the bass is set up correctly in the first place and one typically only adjusts a quarter turn, it would stand to reason to adjust each the same amount unless doing so provides an uneven result.

    DiabolusInMusic likes this.
  8. GIBrat51

    GIBrat51 Innocent as the day is long Suspended Supporting Member

    ^^This^^ I have 3 or 4 instruments with dual truss rods; none of their makers advocate adjusting them different amounts. OTOH, it is sometimes possible to compensate for a neck that's already twisted - a little, by adjusting one rod more than the other. Key words here, though, are "sometimes" and "a little"...:)
  9. Thanks. I can appreciate how it would work that way. I was watching a setup video and the guy said that his natural wood guitars show very little change in neck relief while his lacquered guitars have lots of change. I'm hoping that's the case.

    The one question I have when measuring relief is when you have a 24 fret guitar and are checking you fret the first fret.... but which fret do you press up the neck? I know on my J Bass I will depress the 16th fret (as per John Carruthers). Is it the same? Or do you have to push down something further down the neck, especially because this guitar has a 35" scale length?

    Ya know... You'd think that Ibanez would post a full instruction manual, but I've searched Ibanez's site, searched the internet and cannot find anything that provides any specific help of specs for this guitar... nor do they answer their customer support inquiries! That concerns me. Completely the opposite experience that I've had with Fender or Taylor.
  10. GIBrat51

    GIBrat51 Innocent as the day is long Suspended Supporting Member

    Well, first of all, I'm not a professional luthier or anything, so I'm not telling you what to do here. But, from what I've read, and seen others do, I don't think there's any hard and fast rule about it. If you used, say, the 19th fret to set your relief, the specified clearance at whichever fret you measured it at, might not be enough - and you'd get fret buzz. So, you'd need a little more. Or, it might be fine. It just depends on the bass, and how you play. But, no one's going to come and take your bass away, if you try it. It's just moving your finger down a fret or two, after all...;)
  11. Abner


    Jan 2, 2011
    I use the fret where the neck meets the body. The truss rod will have no effect on the neck past that point.
    bigjames and DiabolusInMusic like this.
  12. Aidil


    Dec 4, 2014
    Jkt, IDN
    Been following that instruction for many years, but then it puzzled me when I got my first single cut Ibanez where the neck meets the upper body at 12th fret and the lower at 24th.


    This BTB also has twin truss rod. Actually, it's my only 5er that has 2 truss rods inside the neck. Previously, I owned several basses with 2 truss rods, but all were 6ers.

    Prior owning this single cut BTB, I always treated the 2 truss rods equal turn. But I never could have achieved the most desirable setup with this bass, until I brought it to a professional bass guitar setup guy.

    Firstly, he straighten the neck with no strings attached. With his special ruler, he didn't need any string to measure the straightness of the neck, thus no confuse on which fret (12th or 24th?) the neck meets the body to fret. He treated both truss rods individually until the fretboard were straight at both (bass and treble) sides. Then he redressed the frets so that they were perfectly leveled. Next he put on all strings, measured the relief (with his special ruler) and adjusted the 2 truss rods individually according to the required reliefs (which were slightly different) of both bass and treble sides.

    So, with two truss rods, I learned that I need to treat both truss rods individually and measure the straightness/relief on both bass and treble sides of the fretboard. Not only at the center.
    CameronJohnson likes this.
  13. UPDATE:
    Thanks for your replies about the twin truss rods. Between the advice here and Jerzy Drozd's manual I was able to figure some things out. Mercifully I've had enough experience setting up Strats and Teles that I'm not afraid of truss rod adjustments and know that "a little dab 'l do 'ya".

    As I'm getting more familiar with the bass and comparing the playability to my newly set up (and wonderfully playing) JBass I've started to develop a sense of what a good bass action is. As I was practicing this morning I got the feeling that I wasn't as nimble as I'd like to have been so checked the relief on both sides of the BTB. I've only been used to checking the bass side. The relief over the G string seemed much higher than I was used to while the bass side seemed to have reasonable spacing. So out came the allen wrench and less than 1/8th turn got it where I needed it. I was also able to gently tweak the bass side too. With such a minor adjustment I could feel my touch lighten and my left hand began to feel much more comfortable. Comfortable enough to take it to a rehearsal this afternoon.

    Thanks for your help all..... Now I have to learn how to use all these fancy tone controls :).
    Matt Liebenau likes this.
  14. Continued update:

    So I took the thing to rehearsal yesterday. One thing I've realized is that going from 4 to 5 strings is not only a different experience, when you have to perform on demand and a bit unfamiliar with an instrument without looking it becomes a much more difficult experience. I'd find myself looking away from the music for a second and then getting lost coming back to the music. Also, much more cerebral than artistic.

    As far as the truss rod adjustment goes, while it was great while at home, things seemed to have settled and I didn't have quite enough relief at rehearsal, so some notes didn't sustain like I expected and others needed a little more strength in plucking. Also, I found that it affected the overall volume balance from string to string. I'm going to change strings today to DR Pure Blues 45-125's which is one gauge lighter than what's on there so I'll save any further adjustments until I get the new strings on.

    I've been doing some continued research to determine if this one is a keeper for me and learned a lot today. I'll tkae those things up on separate thread.
  15. Aidil


    Dec 4, 2014
    Jkt, IDN
    old strings might have caused those symptoms, but I suspect your bass also needs some fret leveling works, which is not a big deal in my case, cause I always brought all my basses to qualified guitar tech to fine level all the frets, which were needed due to climate change after it went out from the factory for quite some times (in order to have low string action that I prefer).
  16. Thanks so much for your thoughtful reply. I'm not sure that old strings cause the symptoms, but I did get new DR Pure Blues strings on it tonight. They are a gauge lighter so I'm going to wait til tomorrow to adjust the truss rods and check the string height. Right now the 1st string is only 3/64ths, and the action feels too low and getting a bit of buzzing as expected. I'll let the strings stretch out a bit and then do a TR, then string height and check intonation tomorrow.

    The sound with the new strings is night and day different. The feel of these round-wound strings is very similar to the old strings coming off. Not sure what was on there except they're not D'Addarios because all brass colored rings.

    And yes, I know it needs a fine fret level which I'll do in the spring or summer after the bass gets acclimated to living in a humidity controlled environment. I had my tech check it out and he said there were a few loose frets and a few unlevel ones. If they are loose, they're not sticking up at all and it plays as if there is nothing loose. I suspect the loose ones (if there are any) may tighten up a bit as the wood takes in the proper amount of moisture. It had a few sharp tangs which I took care of. But those sharp tangs are a sign of wood that has shrunk from dehydration, so I have to think that the looseness will take care of itself.

    Thanks again!
  17. MrLenny1


    Jan 17, 2009
    New England
    I have dual truss rod bass and also wondered the same thing.
    Tension on the rods always appear different, I thought I needed to balance the two for tension.
    Glad I read this thread.
    TB is The place.
    Jon Draffan likes this.
  18. What I've discovered and should have known is that the upper strings have more tension than the lower strings. Consequently the amount of torque required to create the proper resistance shouldn't be equal with both rods. As I've messed with them I've found it is a balancing act that has no formula. I suppose Ibanez had second thoughts about it as the 675's successor has a single truss rod that can be accessed at the base of the neck rather than under a TR cover near the nut.
  19. Tinchi


    Apr 9, 2018
    Dude, I have the same trouble here as you have. I have a Ibanez BTB 1206 and it has a double truss rod. In march I notice that a had some issues with the volume imbalance between the strings. I decided to change the strings and give it a setup. This bass guitar never did have a setup before. when I checked the truss rod, the low side was like loosen and the high side was like stuck. I began to search the web also to find some help from ibanez itself but, NOTHINGGGG. I saw a lot of videos on youtube, but there is no videos on double truss rod, that sucks....:bored::vomit::mad:. I also downloaded the book of Jerzy Drozd. That book helped me a lot, but I still have problems with fred buzz:(
    Where I am from, ARUBA, over here there is no luthier, so I am stuck with this problem. Hope some guys on this blog can help us out:cautious:
  20. Newby6string


    Jan 29, 2020
    I know that this is an old thread. I have an Ibanez GVB 36 6 string bass with duel truss rods. I use a torque wrench 5 to 80 pounds with a 5mm hex wrench adapter. When I adjust the truss rods, it is an 1/4 at a time and I check to see that torque is the same. I tweak the bass side slightly for less relief but never more than an 1/8 turn since I don't use balance tension string sets. To check relief, string action and radius settings, I use a StuMac basic setup kit. Once the bass is set up, I adjust the truss rods twice a year---once for Winter and once for Summer. Of course a setup is required if I change to a different set of strings with different gauges. The torque wrench is a good way to make sure the same amount of tension is on each truss rod and what little tweaking I do on the bass side is negligible. I like my fret board almost flat and use .025 to .115 Rotosound round wounds for a very light touch. My main concern is avoiding neck twist. The torque wrench avoids that problem easily. Hope this helps.
    Amigoz2k60 likes this.