I want to raise my bar height and my quill stem is at its limit. Is there an advantage to a Threadless adapter over a taller quill?

Threadless adapter allows you to use a 31.7 diameter bar. With a quill you're stuck with a 26.0 mm handlebar.

That's a point I was not aware of. Thanks!

I have used an adapter and was very pleased with it. You will have to buy a threadless stem though. I used an adjustable threadless stem for maximum adjustability.

A quill would be cheaper though. An ebay adapter and stem will run you at least $30.

Nitto technomic stem from eBay FTW.

There are a couple quill stems out there with a 31.8 clamp, but they're not cheap and many think they're not pretty. In my experience, threadless adapter can wind up being heavier than a quill setup (note - this is unreliable anecdotal evidence because I don't weigh anything), but I guess that depends on what stems you use.

I'd expect them to. The major weight disadvantage that quill stems have is the expander and redundant tubing in the steering tube area. Quill stems manage to make a little of that weight disadvantage back by not having a connector at the top of the steering column.
From a structural point of view, adapters are the worst of both worlds: you still have to have the wedge expander and a bunch of tubing overlap within the steerer, and you need to have the connection between stem and adapter up above the headset.

I suppose it's theoretically possible that advancements in manufacturing could allow the sum to weigh less than available classic-style quill stems; but in terms of the basic configuration choices, the adapter setup should be heavier than classic quill.

But, I also don't have data for comparison.

I use a threadless adapter on my road bike. While it is heavier (like I really give a damn) it is a little ugly. But ultimately it is much more convenient than using a normal quill stem if you intend on swapping your stem occasionally. I like to swap my stem for a taller one when I do all day rides with my buddies, and this would be extremely inconvenient with a quill stem.

Depending on how much you want to raise your handle bar height, a high rise threadless stem may work just as well. In that case the threadless stem will have less flex.

I only need an inch at 90* less depending on the angle of whatever stem I purchase.

Give us a pic of the bike in question.

Watch out that many MTB stems are 1 1/8 and not 1".

Nitto makes a stem that looks pretty tall.
NEW Nitto Technomic Road 1 Quill Stem 80mm 72 Degree 225mm Quill 26.0 Bar Clamp | eBay

I switched over to an adapter and threadless stem last year on my Merckx and like it. I was able to go with a wider bare and get the bars up a little higher for my 62 year old body. I like the looks of this stem though it does require the smaller dia. bars. VO Quill Stem - Quill Stems - Stems - Components

Plus the cost of new bars/tape, assuming he goes from 26mm to 31.7 on the bars.

I did this on an old Trek 2500, went from a quill to an adapter and 31.7 bars. It was heavy but it allowed me to play around with stem length and angle by trying multiple stems, and I was much happier with the compact drop bars versus the traditional bars the bike had initially.

Why do you want to raise it?

To bring my bars in closer. Palms go numb after 45 minutes.

Do you move your hands around much? I'm only asking because I'm curious as to why you're going straight to higher bars.

^ ^ This.

OP, have you tried other solutions besides bringing the bars up/closer? Are you moving your hands around on the bars regularly? Are your elbows locked straight out in front of you while riding? What type of bar tape and gloves are you using (if any)? Are you doing any core strengthening work in addition to riding?

Before going through the expense of a new stem and/or adapter + bar combo, you might find that there are other solutions that will work for you to prevent hand numbness.

What kind of bike do you have? If it's a classic steel bike, I would encourage you to find a taller quill stem for aesthetic reasons as well as practical. A Nitto Deluxe or Technomic stem will raise your handlebar higher and are available in various reaches, and they are excellent quality. You also would not have to replace your headset, handlebar or bar tape.

Yes. I do move my hands quite a bit. Unfortunately I do lock my elbows after a short while. I don't believe it has so much to do with reach as it does with core training like you said.
Bar tape is lizard skin dsp but it is in dire need of replacement.
I was playing with seat and bar adjustment on the trainer and that's when I had the idea of bringing the bars up around an inch. At that height I was able to read rest my hands on the bars and let my trunk hold my upper body over the bike instead of my arms.

Got it. Yea, as you develop a stronger core you'll be more comfortable riding lower with bent elbows, which makes a huge difference for hand comfort. For now your best bet is doing what it takes so that you can transfer some of the weight from your hands to your abdomen, so if raising things up an inch works so be it.

I'd stay with the quill stem. You can get taller and/or shorter reach quill stems. Here are some:

https://www.rivbike.com/collections/stems

Here's an inexpensive one that might do the job:

https://www.amazon.com/dp/B003Q3SY2Y?psc=1

+1 ^

A threadless adapter will allow more rise than a quill stem (more than a Technomic, even), but if your frame doesn't fit properly it's still not ideal.

Try a shorter (length, not height) quill stem with a bit of upward angle?

it sounds like your bike is set up with more reach than your body can handle. A longitudinally shorter stem is the simplest cheap[est solution ... and the old stem can go back in when/if you are able to ride a little lower.

You can always try a seatpost without set back if the reach is a problem. That brings the saddle closer to the bars by about 1/2 inch.

I have found one for as a low as $20 at a local shop that had one laying around after being swapped out on a a new bike purchase.


The difference between set back and zero setback