Adjusting for mismatched neck and bridge radius

[Elixxrx66]

I have a roller bridge with a 12” radius on my jazzmaster with a neck with a radius of 9.5”. It helps it stay in tune when using the vibrato bar but I do notice the action being a little off on the high e side making the high e side slightly higher than I’d like. Since it’s a roller bridge I obviously can’t file the saddles on the bridge so I went and adjusted it by filing the nut slots instead. It seems to have worked okay. The action now reads 1.5mm on the high e side just like I like it. I guess it doesn’t matter really at this point but I was just wondering if others had done this as well? Thanks

[Debaser]

Filing the nut slot to lower the string isn’t how to adjust playing action, or adjust for radius mismatches. If it made it better, then it was likely too high to begin with. When you press down a string between the 2nd and 3rd fret, look back to see how much clearance you have to the 1st fret. I use a paper’s width on the plain strings. If a string touches the fret, well you likely went too far. Buzzing will occur. The wound strings need a little more clearance, and again I eyeball it. A business cards width for the low E.

Glad it worked out though. I tried asking ABM if they could make a 9.5” roller, but they said cost is prohibitive. Seems kinda silly though, they can machine the same bridge body, and merely make a few more saddles with difference specs. For the money they charge, surely they could do this

[Larry Mal]

It's quite possible that you ended up with three radii, the one that the bridge is, the one that the neck is, and now your nut is very possibly a different radius than either of those.

Or maybe you got lucky, and you got the nut radius to be the same as one of the other two factors, even while lowering it.

Beats me. Glad it's playing well for you- welcome to the site.

[Embenny]

Yep, as was already said, that's not a solution to that problem.

Filing a nut only helps when the string is open. The second a string is fretted, whatever was happening at the nut becomes utterly irrelevant.

[Larry Mal]

Also, if you are that committed to the 12" radius, you could have a good technician make your frets be a 12" radius to match your bridge. Not your fingerboard, necessarily (although that is possible also), but your frets. And then you can make sure that your nut is sorted out and then you have an instrument that is in agreement as far as radius goes.

I read your post about your guitar, and this is one of the things that I absolutely loathe about how Fender was making these guitars. Now, I guess I'm a boring traditionalist who thinks that Leo got it right the first time regarding the Jazzmaster, but Christ, modern era Fender was really puking these things out with no care at all about what they were doing. Putting lame, old and cheap Gibson parts on the guitars with mismatched radius between the fretboard and the bridge just really says that a company doesn't care at all about what they are doing.

Regardless, you like your guitar. There are certainly ways to make it play very well, and there are a lot of ways to make the radius of a Fender guitar be flatter. That thing I mentioned about the frets but not the fingerboard being made to be a specific radius was something I read that Stevie Ray Vaughn did- he's huge on this forum, it's all Stevie all the time. Anyway, his tech flattened the frets to being a 12" radius over the course of some fret levels and that's where they ended up.

[Elixxrx66]

Thanks for all the advice. You would think fender would have thought about that. I forgot to mention I was using a preslotted tusq nut. As for the 3 different radiuses for the bridge, neck and nut I’d never even thought of that. All I know is now it measures 2mm on the low e side and 1.5mm on the high e side so that’s what I’m going by. I have always played Gibson style guitars with a 12” radius neck and a 12” radius bridge. All of this neck/bridge radius is completely new to me

[601210]

If it's higher on one E string than another, it could also be

1. You're measuring from the top of the string instead of under, or
2. Your height adjustment between the two posts are off. I would have tried the thumbwheel on one side before filing anything, personally. If the action is off because of radius mismatch then it should be off uniformly on both sides, right?

But seeing as you've done something and it seems to have helped I guess there's no point arguing what you should have or have not done.