Bought a Chicago made Schwinn single speed conversion. It's been fitted with some modern components up front to which I'm simply unfamiliar with. I need to raise the handlebars. If this was an old quill stem I'd already have it done. However, since I don't know what I'm looking at, I don't know how to approach it. Will one of you good folks inform me as to what kind of set up this is, and "steer" me in the right direction for adjustment?

Looks like a threadless stem on a bike that uses quill stems, has a quill to threadless adaptor.

So it is. Thank you... Now I take it that it business as usual per adjusting a quill stem right? Loosen the long blolt to free the wedge, and go from there!?

That should be right the center bolt should loosen the wedge.

Kinda-sorta, But not quite.
Usually, the quill stem adapters have a top cap held in place by a M6 Allen screw.
Remove this first, and you'll find the thicker and longer wedge bolt below.

Pull adapter all out, to verify length and determine the reasonable amount of adjustment you can make.

Not in this case: I have that quill adapter on the Lemond Zurich I'm building. The screw on the top is connected to the wedge. Loosen that screw and if necessary give it a little tap to unfix the wedge. It should pull right out.

What does that screw into?

If there is something below the cap and cap screw, how do you gain access to the wedge bolt?

The screw in the top cap is a bolt that goes down to the wedge. The top cap is simply there for appearances. Other than that it is a simple stem for a threaded fork

Read what Dabac wrote again.

I did read it and I don't agree with what he said

This is the quill extender in question. The screw goes through the loose cap and extends down to the wedge.

I can see where a separate cap would be useful: you'd be able to leave the quill positioned, and could remove the stem by just removing the cap. But in the profile design unit, there's only one screw.

I have never seen one as you describe; though I have to admit, if have only looked about a dozen different brands. Please post a link or a picture to one like you describe. Thanx.

That was my point as well. I can't understand how what he described could be possible.

Depending on the quill adapter in question, you might not get much lift out of it. You might need to use a threadless stem raiser in conjunction with the adapter or you might need to find a riser threadless stem. This setup looks clunky but gave me the lift I wanted on my RB-T.
RB-T Stem.JPG

I guess if you had a very larger quill bolt with a threaded hole in it. But this would be madness: a high-strength socket headed cap screw is harder than woodpecker lips, and drilling and tapping would weaken the thing considerably.

I could see an alternate design with a large-diameter screw with a hole in it holding the cap down, but ... why?

So I agree with the disagreers: these things don't usually have an M6 bolt holding the cap on.

But I have a question. I'm not too enamored of my Profile Design quill adapter. It's too short, and the wedge doesn't make it as solid as I feel it should be (too much flex). Are there longer quill adapters that don't have as much tolerance on the stem (that is, that have a slightly larger diameter that better fits the steerer tube), or perhaps quill adapters that have a better fixing mechanism than the wedge?

A BBB BHP-21.

A bigger Allen head bolt is used to pull the wedge up against a recessed wall in the stem. The tool socket is drilled and tapped for an M6 Allen, slightly longer than what's normally used to hold a top cap in place.

I've never seen one with the same bolt used for both wedge and top cap.

The one on my road bike doesn't even have a top cap screw. Top cap is simply press-fit, with an o-ring.

The inside of the 8mm socket cap screw is threaded for a 6mm bolt? Only below the head where the wrench inserts?

Just so.

I didn't think it was possible because I didn't think any company would use a hollow bolt to secure a wedge. Especially hollow at the top where the wrench is trying to twist the head off.

I was wrong.

It's really not an issue. Torque is highest at the perimeter, and is steadily reduced inwards, coming to zero at the center. Drilling out the core doesn't remove much torque strength.

Besides, it's not like they're reworking a standard screw. It's easy enough to add a bit of material during design to make it cope with the loads.

Don't know if I agree with the "very" bit. But otherwise, that's how BBB does it.

A high-strength Allen might be. But bicycles generally get away with regular grade fasteners. These can be drilled, tapped, filed etc w/o any drama.

Not really a problem when starting from scratch. It's easy enough to pick or design a bolt that'll still be strong enough when drilled and tapped.
Possible reasons include:
- letting the riders use whichever top cap they prefer
- perhaps a bit weight savings from not needing the thicker bolt all the way through
- the stem can be removed intependently from the adapter/extender.
- maybe patent/copyright issues prompting the use of different designs
I've never seen one with the wedge bolt visible up top.
Different markets I suppose.
Since you don't say how tall your adapter is, its difficult to say with certainty which would be taller.
But you might want to check BBB's adapters.

The wedge is the traditional mounting method. Stems sometimes comes with an expander design instead. Never seen it on an adapter.
Increased rigidity is one of the claimed advantages of threadless stems/steerers.

They're probably all made towards the same fit. Don't think there's any way of promising a tighter fit.
You might try shimming yours.

Soma High Rider Stem Adapter 28.6/22.2 | SOMA Fabrications

Thank you !! I have not seen one like that.

Thanks, Nigel. That is a long stem! But I think that the extra length in the steerer tube would help stability. I'm going to try to get a threadless setup, or this. This is a good alternative.

dabac, thanks for the nice (and civil!) explanation of your experience and for the description. As I mentioned, I think the design you describe could have advantages: the cap and stem could come off without loosening the quill.

The picture I posted gives one an idea: it's about 5.8 inches (a bit less than 15cm) long.

I think a longer one would give me more length in the steerer tube and any wiggle would be minimized. A shim could work, but Id have to figure out how to ensure it didn't shift. I think that the best solution may be to put in a threadless fork and use a 1 to 1-1/8 step shim to use my current stem on the 1 inch steerer. Thanks again.