All right this may be my dumbest question yet. However I don't claim to be a bike expert or a brain surgeon.

Considering the somewhat steeper angles that at least some "Ergo" bars have will they work with a traditional quill stem assuming the stem clamp / bar diameters match.

I'm really interested in Ergo bars as they look to me like they would be far more comfortable then a traditional bend. However Rivendell wouldn't agree from what I see on their web site.

I have had mostly OK results feeding Ergo bars through a standard stem, but once in a while they just won't go. The ones with a "bump" in the drop area seem like the troublesome ones. I was never that thrilled with any significant increased comfort from Ergo bars versus the standard bend drops, but YRMV...also they usually just look bad on most C&V bikes, IMHO.

Not a problem. Just make sure your sizes match. The "rippled" ergos do look funny on an elegant stem, but the ones that simply flatten out the middle of the drop curve look ok and work just fine. I just put a Cinelli Eubios onto a 3T stem, and the combo looks OK. The tape wrap softened the ripple quite a bit.

Still, IMO, there's no substitute for an elegant Cinelli stem holding a Cinelli bar. Light, strong, graceful, and not that different than the ergo until you get to about 25 miles or so.

If you're looking for a comfortable bar that looks good on a C&V bike consider the Nitto Noodle. It has a lot of good hand positions on the top, ramps, and hoods which is where most people spend most of their time on. I don't spend much time down in the hooks and when I do there isn't a lot of weight put on them so they're comfortable enough.