I know it's not very vintage, but I've gotta go with a threadless adapter.
I need the 21.1mm quill diameter size, and a 1 1/8" top size
It will go below a reversible V-O 17 degree stem, in the 120mm length, linked here: https://store.velo-orange.com/index.p...0-17-rise.html

My question is, does anyone make this item in an alloy? I'd like it to somewhat match the VO finish, I'd like the stem bolt to have a recessed allen head, and I'd like it to be longer than 6". (no comments, please...)

My search so far has been unproductive...

Any online suggestions or, if you have something in your box-o-stems, I'd gladly welcome a PM.

Thanks!

At one time they were all alloy. Keep looking, they're out there.

Is this one junk?
Do you think the bolt head would recess into the black piece?
I can't imagine something working well for both 21.1 and 22.2.

A couple other members have mentioned Soma producing a very tall 1-1/8" threadless adapter in aluminum. It may not be 21.15mm OD but being aluminum it would relatively easy to reduce to the correct diameter.

I had a local machine ship turn three of the VO adapters down to 21.1mm. I'm using one and I sold the other two.

I did exactly the same thing (but just for one, not three adapters).

The V-O adapter turned down to 21.1mm is in the center. The original 21.1mm stem is on the left, and a stock V-O adapter (22.2mm) is on the right.

Yes, T-mar, I looked up the Soma ($30) and it is indeed very long - extending almost 9" above the min. insert line! Does not come in a 21.1 diameter, but like you said easy enough to shave off the thickness.

Colonel, that is a beautiful setup. (Is the cool compass part of the adapter, or an add-on?) If I can accept the 7" total length, it is a nice-looking piece for $16. Plus, it would likely match the finish of the VO stem I will be using.

I'm currently having a guy turn a seatpost from 27.2 to 26.8, so I'll see how much he charges.

Scooper, did you need a different wedge for the turned-down version?

Thanks for the replies and suggestions!

The compass is just a cheap little thing to fill the space left by that particular stem, which is taller than the 1 1/8" area of the adapter. The adapter doesn't quite match the finish of the VO stems, but it's easy enough to polish. You will need to use the wedge that came with a 21.1mm stem or modify the wedge that comes with the adapter.

I think my machine shop charged me $50 to turn down all three of them.

I just used the wedge from the original 21.1mm stem (notice the wedge is missing from the original stem on the left side of my photo, above).

I bought a 21.1 threadless stem adapter (I think it was aluminum) don't remember the name of the online shop, it was a tandem specialist, and the adapter was for the stoker's stem/bars. Has an ugly rounded top cap/wedge bolt... Someone's asked this question before, try searching.

I think that would be the Manowar threadless adapter from Crank2Perform. It's steel, and has a big hex head bolt on top. It is 'Potts mod' compatible, but I have yet to think of a way to make that useful.

Do a search on fleaBay for threadless French adapter. Contact the seller and he will turn one down for you for the same price. I had him do that for my Lejeune tandem. Think it was $35.

Love the look of this one & the compass.

Me, too. Colonel, how do you have the compass fastened down? And how'd you manage to find one that was exactly the right size? Not to hijack the thread or anything.

+1 Have used on of these and they work fine and last I checked the guy is willing to turn one out in whatever size quill and top you want for about $40.

That's a good price.

I haven't yet figured out a permanent solution. Maybe hot glue? I don't have a hot glue gun, though. So far the fold of electrical tape is working.

I just looked for a compass 1 1/8" in diameter and found some inexpensive ones on Amazon. I'll send you one if you like.