The Workbench

To alter the Bigsby B7 or not… *usual suspects*


Okay, Let's get the "under or over" discussion out of the way first....

Factory Prototype Jet or not, the B7 tension roller on my 6129T players edition is giving me tuning instability and a pretty dull vibrato.

I could live with the tuning instability for a while, but in the last couple of string changes, it's starting to get my goat. fwiw 10-46's if you were going to ask.

So perchance / mistake / inattentiveness found me having half restrung the bigsby without running the strings under the tension roller this morning. I just wasn't paying attention.

Damage done - eh whatever, but lo and behold.... the damn thing is bang on in tune, AND stable. Not only that, but the vibrato spring reaction / sensitivity is almost as good as my Duesenberg. In other words, it's just about perfect.

Now I know this is not a new idea, but I did want to dot some i's and cross some t's off before pursuing this a little further.

I've come across 'biggsfix' offset tension roller for a B7 bigsby - and I am wondering if anyone here has fitted one, after perhaps stringing over, rather than under the tension roller. If you have one fitted, could you please advise the following:

  1. can the tension roller height be set / adjusted or is it located in one position only?
  2. what is the diameter of the tension roller (i.e. is it different to the factory Bigsby roller) and what is the offset from centre?

I ask this in advance, as I am not certain that an offset tension roller would be the 'cure' for this particular instrument, but I am curious whether or not a smaller diameter roller or smaller offset biggsfix roller may be beneficial.

The thing is, the breakover angle is actually quite respectable with the strings under the tension roller. With the strings over, the breakover is like an old archtop and trapeze tailpiece, minimal at best.

Strings aren't jumping out of saddles like they were famous for on Jazzmasters, but comparitively speaking, the jazzmaster fix was a staytrem bridge with correctly spaced and sized roller saddles.

I would like to have a fraction more breakover angle, but I don't want a tension roller that sticks out like dogs bollocks, which the biggsfix appears to do on some of the images I have seen.

Any other advice on possible spring selection or changes would be appreciated, if you run your strings under the tension roller.



A couple rubber washers between the Bigsby and the body is a very low cost way to see if it helps your guitar. Billy Zoom did this years ago on his Silver Jet.


I installed the Bricks BiggsFix on my Broadkaster Jr several months ago with GREAT results -- as detailed in this thread:

The BiggsFix roller is 13/32" in diameter. It is a "set" height -- not adjustable. Installation is easy. The stock roller is removed but its axil is used for installing the new raised roller. Above is the "after" view on my Broadkaster.

The BiggsFix seriously reduced the break angle which cured my tuning problems -- instantly.

I also installed a Reverend Soft Spring which corrected the Bigsby action. Those springs are only available in chrome (which you can see in the photo. The guy who makes the Bricks BiggsFix also has "Squishy Springs" which are the same as the Reverend but are available in chrome and gold.

Others here who have had similar (good) experiences with the BiggsFix are giffenf and BabaJoe.


Here is the "before" photo of my Broadkaster. Comparing the two photos shows the difference the BiggsFix makes in the break angle.

I've been surprised more people have not reported tuning instability problems with 13"-14" body guitars with B7 Bigsbys.


Here is the "before" photo of my Broadkaster. Comparing the two photos shows the difference the BiggsFix makes in the break angle.

I've been surprised more people have not reported tuning instability problems with 13"-14" body guitars with B7 Bigsbys.

– senojnad

I think people may be embarrassed to report tuning instability here. I've noticed that many of us are quick to respond, telling them that there must be something wrong with their nut or their bridge if their guitar is not staying in tune.

Here is my honest experience. With light Bigsby use my guitar will return to pitch or at least it sounds like it does until I check the tuning with a tuner and realize it's not exactly in tune. As I use the Bisgby more and more the guitar will eventually go noticeably out of tune.

To be fair this is with all tremolo (vibrato) systems I've used. I never owned a Floyd Rose or Kahler type locking system so I don't know about those but with Bisgbys, Stratocaster and Jazzmaster systems this is the way it is. I have dealt with it by tuning up in between songs every time I wank the bar during a song.


I had exactly the same experience you did. my 6128 came from the factory with B7 with the horrible string angle going over the bridge. the guitar was totally unusable due to tuning instability. i tried running the strings over the tension bar instead of under it, and it immediately cured the problem 100%. there is just barely enough angle to hold the strings in their saddles now, but it's a heck of a lot better than the tuning nightmare i was having. now the strings stay in there saddles even with hard picking/strumming. once in a while i'll pluck the e string upward with my little finger and it will jump out of its saddle.


I went through this with my Guildsby equipped Starfire V and posted the results of my modifications. Basically I raised the body of the Bigsby a little higher to reduce the break angle and installed a Reverend Soft Spring. I was pleased with the result and you can read the earlier post here:


One trick I do on B7 to reduce the angle a bit is to pop off the tension roller cylinder and string under the remaining pin, which is a smaller diameter. That may not be enough in some cases like these but if you're looking for a middle ground its worth a try.

I may reference e this thread in a new One as im having Bigsby issues too!


Try loosening the front screws. The arch top meeting the flat base of the bigsby can cause the roller shaft to bend slightly causing just enough friction to stop the roller rolling. The Billy Zoom fix is brilliant as the rubber washers allow the bigsby to remain flat and raise the string angle over the back of the bridge.

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