SLSMG fretboard radius (also JT390 bridge saddle radius) ???

[turbocharged110]

Hi everyone, I recently picked up a used 2005 Jackson SLSMG and am really enjoying it. Question I have is about the fretboard radius. In my research into this guitar I have found conflicting information...some places say compound 12-16", others say compound 16-20". Does anyone know which, if either, of these numbers is correct?

Also, I have been thinking about replacing the JT390 bridge with either a Tonepros or Hipshot replacement and am wondering what the bridge saddle radius is as well. Anyone know?

Here's a picture of the new guitar. Not in perfect shape by any means, but I'm happy with it for $350. It also came with Planet Waves locking tuners and Seymour Duncan JB/Jazz pickups, but I will probably replace the pickups.

[toejam]

It should be a 12" - 16" radius. I've never heard of Jackson doing 20" unless it's maybe on an 8-string.

As far as the bridge, no idea what radius it is.

[Number Of The Priest]

An SLSMG for $350 is a steal. Congrats!

By default, the majority of Jackson/Charvel guitars have 12-16" radius. Very few guitars don't. Off the top of my head, the lower end Juggernauts and the lowest JS Series guitars don't.

I haven't heard of any companies doing 16-20" radii, but that doesn't necessarily mean there aren't guitars existing that have this. Certainly not any Jacksons/Charvels that I know.

Use a radius gauge set to determine the radius of the JT390 TOM bridge (example of a set illustrated below) and buy a corresponding aftermarket bridge with the same radius. Word of caution: Due to the compound nature of a "typical" Jackson/Charvel fretboard, the radius cone formed by the strings would continue to "flatten out" well beyond the 24th fret, and I cannot imagine the JT390 having a very flat radius and being appropriate for Jacksons/Charvels in the first place. Reason why I state this is because even OFRs come stock with a 10" radius across the saddles, far more "round" than even the "roundest" part of a Jackson/Charvel fretboard that starts at 12". It's mismatched. Most players don't notice. In the pursuit of perfection and the lowest possible action across the entirety of the compound radius fretboard, at least it's possible to shim OFR saddles to match the flatter radius required at the bridge, but off the top of my head I don't believe you can shim TOM saddles; you'd have to file the slots lower on the middle saddles to "flatten" the radius at the bridge.

[turbocharged110]

Thanks. Good to know that it is 12-16" which is what I was guessing considering it is much easier to chord near the 1st fret than my straight 16" radius Ibanez.

You are right about TOM saddles not being shim-able, only the entire bridge left vs. right to get the correct low-E to high-E taper. Reason I ask about the JT390 radius is because all the replacement bridges that fit have a 12" saddle radius and I want to make sure that won't mess up the action.

[Kisonen]

You need to file down sting slots a little bit on TOM bridge if you want it to fit compound radius Jackson fretboard has. I did that to my SLS3 when I replaced the bridge.

[Mudlark]

Wouldn't Gotoh make a proper replacement? Pretty sure they make the USA TOM bridges.

[Kisonen]

Wouldn't Gotoh make a proper replacement? Pretty sure they make the USA TOM bridges.

Gotoh only makes 300mm ( roughly 12") radius TOM bridges. Diagrams can be seen on their website.

[Mudlark]

That works fine in my SL2HT. My understanding is it's a Gotoh...stamped 'JAPAN' on the underside, but I may be corrected.

[turbocharged110]

So what would the optimal bridge radius be for a 12-16" compound radius neck? It seems like you would want it to be a little flatter than 16" to ensure it matches the neck radius at all points. Reasoning is that if the bridge is set at 16" radius, then it will be less than that at the 24th fret assuming a constant taper.

[Number Of The Priest]

In an ideal world, a Jackson/Charvel guitar's bridge should be about 20" radius. Previous discussion: https://www.jcfonline.com/threads/14...-SADDLE-RADIUS

[turbocharged110]

In an ideal world, a Jackson/Charvel guitar's bridge should be about 20" radius. Previous discussion: https://www.jcfonline.com/threads/14...-SADDLE-RADIUS

Great, thanks for the info and link.

[Mudlark]

Can't recall the radius, but I tried a Wilkinson roller bridge on my SL2HT once..
...unplayable.