Breathegood

I agree about the sliding vertical dropouts being ideal for a belt drive with the exception of weight. My Twin Six is split in the "U" of the track end to feed the belt through and there is an insert to tie it together once the belt is in place. It is simple, elegant, and light. Sure it takes a little more effort to properly set belt tension and line the wheel up straight, but it's an acceptable trade-off on a frame that was intended to be a SSCX race bike.

I'm referring to my LBS owner. I don't have the patience anymore to do my own builds. I trust him implicetly with all my bikes, and I don't let other techs touch my stuff. He has put together five bikes for me over the last 10 years or so. He knows what I like, and doesn't try to push me towards a floor model that is a sub-par compromise. My Gary Fisher is the only bike I've had in the last 17 years that is "off-the-shelf", and it is my least favorite. All my other bikes began with a bare frame. I tell him what I want (usually starts with a frame that appeals to me) and we work together to design the right combination of components and he puts it all together. I'm currently having him resurect a 1996 Cannondale SR500 road bike that I purchased new. I am having to replace the HeadShok (that's right, it was a road bike with front suspension!) with a ridged fork by Wound Up because the elastomer damper is toast and irreplacable. The bike always fit me very well and was agile and comfortable. It was my first road bike so it has some sentimental value to me, but has been sitting as a bare frame for about five years now and it is time to bring it back to life. This will be it's third incarnation, and its intended purpose will be light commuter outfitted with a small rear rack and top mount basket. Next year I plan to have a custom made titanium frame with similar specs to my Twin Six, but with disc brakes and more touring-friendly ammenities like braze-ons for water bottles, racks, and fenders. Just haven't decided on what frame builder I like best yet, but my guy is doing some research for me, and will have a short list ready when I'm ready to drop the coin.

fietsbob

Have a Koga Miyata with a Rohloff, chain drive, sliding dropout, works fine.. cogs of steel are long wearing..

Tout Terrain has a dropout split down the center closing the axle QR holds it together , (+a bolt, chainring type)
Tandem Eccentric BB for the tension.