Threadless adapter on my De Rosa
 

I happened to have the bar, stem, and adapter, and wanted to try the Deda 90mm stem and Newton deep bars on the De Rosa. Anyone who says using an adapter doesn't give you added stiffness is dead wrong! This setup is way stiff. And, I love the Newton Deep Belgian style bars - nice flat ramp, and nice deep comfy drops. I was thinking of looking for a 90mm quill stem and using the Deda 215 bars, but I may just stick with this for a while - even though C&V guys will want to kill me after seeing the photos! Although, the new Neo Primatos all come with the same stem and bars (in a real threadless setup).

http://i42.photobucket.com/albums/e3...2/NIK_1064.jpg
http://i42.photobucket.com/albums/e3...2/NIK_1067.jpg

Oh, the humanity!

Andy I agree with your assesment. I have a threadless adapter on my Schwinn Circuit with Bontrager Race X bars and stem and its considerably stiffer.

Stiffness is not the problem. Ugliness is. Threaded headset+threadless stem = too busy.
And yes, I've done the same on a bike.

That's what she said!

If I could find a nice 90mm quill, I would just get a set of the Deda 215's in 26.0 - to make the bike less ugly! But 90mm stems that don't weigh more than my adapter plus stem are hard to find these days.