MIMF

I am doing a setup on a guitar with a Floyd Rose bridge, and locking nut.
The only way to raise a locking nut is to use shims.
This nut needs to come up more on the bass side, than on the treble side.

My concern is that by using different thicknesses of shims on either side, that I lose surface contact under the nut.
Is this something I need to worry about?

It happens..I use the standard shims and rely on a little distortion to handle the gaps. Could be worse...the new Gibson nut is screw-adjustable, so lots of gap and no shims.

That's kind of what I was thinking Todd, thanks for confirming.
This, and the Gibson thing sort of goes against the principles we've all been taught.

Can guitarists hear the difference? Most guitarists can't even tune on their own so I doubt it. If you really wanted to deal with it you could rout the nut plane over again and use a thicker shim.

David,

If I did that, I would have to rout the nut shelf on a very small angle. I only needed .015 on the bass side, and .005 on the treble side.
Very hard to rout that kind of angle into the shelf.
Unless you have some method I have not thought of.

I would probably dress the nut down a bit on the treble side bottom, so that I could use a flat shim. They are brass, aren't they? Little bit file, maybe even sandpaper on a flat table top.

I have made custom tapered shims for locking nuts. I usually shape them on my disk sander from some mahogany scraps.

The nut parts are actually hardened steel and not easy to file unless you go at them with diamond files or a dremel disc. A pillar file is good for filing a nut flat at the correct angle. No need to set up for some complicated routing operation although that wouldn't be very hard to do and might come in handy for all sorts of repair jobs.
Another option is to use a thixotropic (thickened) epoxy and some butcher's wax on the bottom of the nut plate. PC-7 epoxy or polyester based bondo would be a quick and dirty solution or the wood colored epoxies from Mohawk that come in putty stick form that you kneed with your fingers.

I use the StewMac stuff - they offer soft copper shims in 4, 6, 16, and 24 thou...minimize the gap and the copper will do a decent job of distorting to get a decent fit. Alway an option to use .0015"-.002" copper shielding tape with adhesive removed for fine tuning...I buy 55 yard rolls of the 2" wide for shielding at about $60....strip the adhesive with naphtha.