Testing the waters custom quill adapter.
 

Is there such a thing with quill adapters to where the 1-1/8” stem is a perfect fit on the quill adapter to where there is no adapter showing above or below the stem. And where the adapter fits flush to the headset. Just asking for a friend...

The Nitto adapter is square shouldered and not tapered like others. All you need are spacers and build up the exposed adapter with tape

That Nitto looks like a good way to go. ^^^

The Profile adapter stem isn't as pretty but looks like it would do about as well. There's also the Innicycle adapter headset if you want a perfect looking job. Made I believe by a forum member.

Keep in mind that vintage bike frames with level top tubes were never designed to be used with slammed stems. That innovation was made possible by frames with upward sloping top tubes, and 'racing' bars that have been rotated to a touring position to move the hoods up. :50: :innocent:

1 1/8" stems come in a variety of heights, though most tend to be around 40mm (31.8mm bar clamp diameter...26.0mm bar may be a little less). Most quill stem adapters have 40mm tall 1 1/8" sections, some a little more, some a little less. It's a crapshoot. Nothing will get you 100% flush/on the headset, though I think that's fine as it allows for a touch of flex (and no contact-created creaking). The gap is usually only a few millimeters, which is hard to see. You will have to get an adapter that has crisp/squared-off edges when going from 22.2mm to 31.8mm (1 1/8"), and one that has that transition happen quickly, not over a long taper/height. These are thankfully easy to find. Only an Innicycle headset conversion will get you "the purity" of the look, but you gotta pay to play. It's beautiful, but I have not decided to play just yet.

https://cimg5.ibsrv.net/gimg/bikefor...94a9eea43a.jpg