Friday, October 4, 2013

Threadless and Quill Stems

Bicycle headsets and stems have changed a lot in the last couple of decades. For most of the bicycle's history, the standard was the 1-in. fork steerer and threaded headset with a quill stem. There were variations in headset threading; British (which essentially became ISO), Italian, French, JIS (used on some Japanese bikes), and even a few others; and small differences in stem dimensions (22.2 mm for most, 22.0 for French, for example). Although those variations make it a little tricky sometimes when repairing or retrofitting vintage bikes, by the late 80s, things became much easier as British/ISO became the main standard that supplanted most others. Only Italian remained, and it was more or less interchangeable with ISO, so it didn't matter. The 1-in. steerer was (and still is) plenty strong enough for steel-framed bikes.

I know I used this picture in a different post, but that Nitto
I-beam stem is just a gorgeous piece of forged metalwork.
In the late 80s, the rise of mountain bikes brought the first major change in headsets: the increase in diameter from 1-in. to 1 1/8-in. The way I recall it (though someone is bound to tell me I'm wrong) is that the change was made not so much because the 1-in. steel steerer wasn't strong enough for MTBs -- but rather because the increase in size would improve the life of the headset bearings. The added strength of the fork was a bonus. Yes, I could be remembering it wrong. In time, some MTBs even started appearing with 1 1/4-in. headsets (if big is good, bigger must be better). In the 1990s came the threadless headsets with stems that bolt onto the outside of the steerer, rather than quill stems being inserted and tightened with an expander wedge inside the steerer.

While the threadless headset/stem system first swept the mountain bike market, they took a little longer to take over the road bike market, but they did more or less take over. Today it is hard to find a bike that still takes a threaded headset and quill stem. Although there are certain advantages to the threadless headset system, the advantages are, I believe, more heavily tilted to the manufacturers than the consumers. Easier installation, and less variation in stock - manufacturers no longer needed to keep forks with different lengths of threaded steerers -- it became a one-size-fits-all world (at least for a while -- I'll come back to that).
Threadless stem - 1 1/8-in. -- Although the Velo-Orange
polished aluminum stem is one of my favorites for road bikes,
some might find it a bit proportionally large for a steel frame.
What is worse though, is the thickness of the spacers --
making the steerer look as big as the head-tube. Since this
photo was taken, I had a set of silver spacers thinned
down by a machinist. It looks a lot better now. Why doesn't
 someone just make thinner headset spacers for steel frames?

I don't really have major issues with threadless headsests -- even as a Retrogrouch. They do adjust easily; they give a more "solid" connection between the stem and the steerer; and the stems can even be a little lighter and stronger at the same time. On the other hand, they don't allow for as much adjustability in height. Once the fork steerer is cut to length the options become limited. And on some bikes, especially classic-proportioned steel bikes, they can really throw off the aesthetics. Install a steep-angled stem to get the bars higher, and the look gets pretty weird.

By the way, as far as aesthetics and proportions go, nothing looks "weirder" to me than a carbon fork (usually with hugely oversized blades) on a steel frame. The fork shouldn't be larger than the frame tubes IMO. The stem shouldn't be larger than the frame tubes, either -- but many/most threadless stems are.

Most of the bikes I own have 1-in. headsets and quill stems. All of my bikes are steel; all of them lugged. Quill stems are svelte and have the right proportion for steel bikes. That alone is enough for me.
Early 70s 3ttt Record stem -- beautiful proportions
for a classic steel bike. 

There really aren't that many "drawbacks" to the traditional quill stem. One argument I hear for threadless over threaded is that you can adjust a threadless headset with allen wrenches which can be carried on a ride, as opposed to the large open-end wrenches needed for threaded headsets. OK - but if the headset is adjusted properly to begin with, there won't be a need to adjust it on the road. Some like to point out that an over-tightened quill stem can bulge the steerer tube. Yes -- so don't over-tighten it. (Interestingly, some of the same people who would make that complaint don't seem deterred by carbon fork steerers that can be crushed by over-tightened threadless stems.) Then there's the issue of stems becoming "frozen" in the steerer because of sweat and corrosion. Yep. That's what grease and maintenance are for. I've only ever seen it happen on seriously neglected bikes.
Here's a 1-in. threadless stem -- fillet brazed
from chrome-moly tubing. It had to be custom-
made, but it does offer a more "classic"
proportion for a steel-framed bike.

Back to that one-size-fits-all world. On road bikes, even as threadless headsets took over, the 1-in. fork remained common for a while. As I pointed out, the 1-in. steel fork steerer was more than strong enough. But as forks and steerers started being made in other materials -- first aluminum, then carbon -- the strength of the steerer became more of an issue. In time, 1 1/8-in. became more common on road bikes too -- partly because of the strength issue (at least with non-steel forks), but again, I suspect it makes things easier for the manufacturers -- fewer variations to keep in stock. But now with the all-carbon wunderbikes, there have still been plenty of failures, and the fork-crown/steerer junction seems to be a weak link. It's an issue that gets all-too much ignored. But one should ask themselves why so many carbon-steerer forks are now made 1 1/4-in. at the bottom, tapering to 1 1/8-in. at the top. It's obviously a strength issue, but don't expect to read that in the ads. Anyhow -- I'm starting to digress, so carbon forks are just going to have to be a subject for another post.


10 comments:

  1. To me the drawback of the threadless stems is that they're extremely ugly. I hate the ugly external clamp screws and the fact that the stem extension is almost never horizontal, like God intended it to be. (Okay, sometimes it's parallel to the sloping top tube of the new bikes, which is another "modern" feature that assaults my sense of aesthetics). It saddens me to see today's builders, who tout themselves as "keepers of the flame", using these ugly, klunky 90 degree threadless stems. The stem in your third picture doesn't look quite as bad, but it would be 100% better if the extension were horizontal, not sticking up in the air like a sore thumb.

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    1. I agree with you -- as I mention in the post -- functionally I don't have any issues with them. My main complaint is aesthetic -- especially with steel-framed bikes. The best way to go for a threadless stem on a steel bike is to have something custom-made out of steel.

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  2. The threadless stem/headset travesty is primarily to save OEM manufacturers assembly time and money. Loose ball bearing headsets maximize the surface area touching the race and minimize possibilities for brinelling. Then caged bearings were "innovated" which speeded assembly, reduced costs but reduced the number of bearings and increased the likelihood of brinelling of the races. Change not progress. I'll just stick with my Stronglight A9.

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    1. The Stronglight A9, and the Stronglight Delta, were some nice headsets -- they'll last a long, long time.

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  3. I don't mind the aesthetics of threadless. I don't care for the stack of spacers - if it were me I'd simply have an appropriate length tube cut as a single, tall spacer.

    I also don't mind a carbon fork on a steel frame (I have a Felt F4130 in my collection) - they don't have to be ungainly.

    http://www.motostrano.com/Felt-F4130-Athena-Road-Bike-p/f4130-a.htm

    One nice thing about Aheadsets is the variety of stems available - lots of lengths and angles - way more than with quills. Finally, although you can get "capped" or two-bolt quills, they are rare. That means bar tape comes off more frequently for maintenance. And quills often scratch the bars.

    You didn't mention the "death quill" either :-)

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    1. death quills -- you must be referring to those old Ava stems from the 70s. I've never actually seen a broken one, but I do know they were awfully light -- apparently too much so.

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  4. Interesting commentary. I'm sure you've seen threadless stems attached below the top of the steerer tube with more spacers added above it - as an alternative to having the steering tube cut. I'm tall enough that cutting is usually not a consideration, but for those with extra length in the steerer, I would advise them to leave it uncut. It gives you better adjustability and the next buyer of your bike will appreciate that.

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  5. I agree totaly with the author of this article and with John.
    And this is wright ... steel bikes are svelte and have the right proportion.
    Well this is of course personal opinion.
    I should like to ask if there is anybody who know what treatment is applied on stems made in Italy to be so shiny. I bought some time ago a Dancelli from '80 and the former owner did not care too much about the aspect and the stem was with scratches. I mechanically polished it but I can not get the shine which is present also on stems from this article and, more than this, after polishing I observed that the surface is extremely sensible and is very easy to scratch it.
    So, does anybody know the right treatment to get the original aspect and also hardness of stem surface?
    Anodisation is out of discussion as it give dull or mat surface.
    Thanks.

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    1. Some of that shine aspect you mention comes from the type of alloy used in the stem. Cold forging takes stronger alloys, and they are typically the ones that can take the nicest shine (and keep that lustre longer). If the stem had been anodized originally, you'd need to remove all traces of the anodizing before you'd be able to get a good shine. If it's a softer alloy - as might be used on a hot-forged or melt-forged stem, you can get a decent polish, but as you mention, it doesn't seem to last long.

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  6. When I was a much younger faster ATB rider, the threadless 1 1/8 was a gift from god especially before really good suspension. If you are on a road bike that does not go over 40mph on a descent or regularly push above 27-30 mph in a sprint, I am not sure if there is much of bonus to outweigh the aesthetics for a steel road bike. I do like the way flared headset handle shock and handling.

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