Bicycle Mechanics - Threadless vs. Quill

What exactly is the difference between threadless and quill systems? Is threadless really better? Why?

Thanks,
velo

Threadless is supposed to be lighter because the set-up does not require a quill to be fitted into the steerer. (I wonder how much weight that saves.) What you lose with threadless is the ability to adjust your stem. If you want to try to raise your handlebars with an aheadset, you have to buy another stem. With a quill stem, you just raise it. My vote (6 roadbikes worth) is for a quill stem.

Threadless is slightly simpler mechanically than quill, principally because it's a somewhat more modular design. The main point of failure on quill stems is the binder wedge; the analogous part on the threadless headset is the star bolt, which is considerably more accessible for self-service and maintenance. The other advantage to threadless is that it is pretty simple to swap, flip, mix and match stems, which is more of an interest to bike shops than to riders...

Having said all that, it's really six of one and half-dozen of the other. My preference is threadless but they really are about euqal in terms of reliability, weight, maintenance and almost anything else you care to mention.

I prefer threadless. It's simple and it works well. I remember beating the snot out of quill types when I was younger trying to get the damned things dislodged. Of course now that I'm older and wiser I know to just get a bigger hammer :)

Aren't quill systems getting harder to find? I image with the integrated headsets coming up the quills will fade away and threadless will reign.

Originally posted by Bobsled
Aren't quill systems getting harder to find? I image with the integrated headsets coming up the quills will fade away and threadless will reign.

That's part of why I was asking. It's not a real big problem yet, but there are a lot of models that only come in the threadless kind. Then, yes, with the integrated headsets, the threadless will probably become even more popular.

I have all quill stems, and I just wanted to know if the advantage of threadless was anything significant, but from the posts here I guess it is not.

One point or two not mentioned yet, since no threads have been cut into a threadless steer tube, the threadless tube is stronger than the threaded/quill type. If the the tube is the standard 1" variety threads can be cut into it accept the quill/thread system. If you try the newer system and don't like it, you CAN go back.

Ride Both Ways
Pat

The biggest advantage of threadless systems is for long distance tourists. You can adjust them using only allen keys, so your toolkit can lose the headset spanners.

I like threadless strictly for ease of swapping things out. I always seem to be playing with something - handlebar, stem length, etc. With threadless stem with two bolt clamp, I can pull the bar off to change stems in just a few seconds. I also might get a wild hair to swap handlebars from one bike to another to try the shifters or something. Who knows? To me, playing around with this stuff is part of the fun of riding. When I changed forks on my commuter, I changed to an actual threadless fork, but before that I had installed an inexpensive quill-to-threadless adapter and short threadless stem when I wanted to shorten the saddle to bar distance. I also installed a quill-to-threadless adapter on my road bike for the same reason.

You can get a 1 1/8" q-to-t adapter from chucksbikes.com for either 5 or 8 bucks and threadless stems from $5 up. It's an easy inexpensive way to try different stem lengths. The stems are decent brand. To me the nice thing is to be able to try different stems cheap. You can always spring for that Ritchey WCS stem once you figure out the length you need using 5-dollar stems. I got the 1" Cinell q-to-t adapter for $20 from cbike.com.
FWIW,
Raymond

The big reason for the switch to threadless is due to weight. Not of the stem, but of the steerer tube. Newer forks switched to aluminum steerer tubes and the threads did not hold up. Someone (who I don't know) decided that a friction clamp would work and not weaken the connection. Thus, threadless was born (or invented). Now some manuf. (like Cannondale) are using Carbon Fiber steerer tubes.

I don't think quill stems will ever dissappear, but threadless will (has) become standard.

Threadless steerer headsets were re-invented. Cheater-Lea used to make them in the 1930's. I dont think there is anything new in cycling.

Threadless is supposed to be lighter because the set-up does not require a quill to be fitted into the steerer. (I wonder how much weight that saves.) What you lose with threadless is the ability to adjust your stem. If you want to try to raise your handlebars with an aheadset, you have to buy another stem. With a quill stem, you just raise it. My vote (6 roadbikes worth) is for a quill stem.

You can still put spacers underneath a stem to raise bars with a threadless steerer, you just have to know not to cut the steerer too short in the first place...

Threadless is slightly simpler mechanically than quill, principally because it's a somewhat more modular design. The main point of failure on quill stems is the binder wedge; the analogous part on the threadless headset is the star bolt, which is considerably more accessible for self-service and maintenance. The other advantage to threadless is that it is pretty simple to swap, flip, mix and match stems, which is more of an interest to bike shops than to riders...

Having said all that, it's really six of one and half-dozen of the other. My preference is threadless but they really are about euqal in terms of reliability, weight, maintenance and almost anything else you care to mention.

I've yet to have a star nut fail (or a binder wedge for that matter), but if it does fail it's not going to affect your ride because you'll know it failed before you finished adjusting your headset...

Threadless is slightly simpler mechanically than quill, principally because it's a somewhat more modular design. The main point of failure on quill stems is the binder wedge; the analogous part on the threadless headset is the star bolt

Beyond it's use for preloading the bearings, the star-nut has no use. It could burst into flames and not impact the integrity of the system.


The big reason for the switch to threadless is due to weight. Not of the stem, but of the steerer tube. Newer forks switched to aluminum steerer tubes and the threads did not hold up.

While that is probably a factor, one of the biggest factors driving the change was that the manufactures no longer had to provide a range of threaded forks for a given model. The threadless fork is one size fits all.


Does anyone have pics or diagrams that would illustrate the difference between threadless and quill?

Suggest you start with Sheldon Browns website. Tons of information there.

Beyond it's use for preloading the bearings, the star-nut has no use. It could burst into flames and not impact the integrity of the system.

I do think that could be a bit distracting to the rider though:)


.. one of the biggest factors driving the change was that the manufactures no longer had to provide a range of threaded forks for a given model.
+1


The threadless fork is one size fits all.

Until the point when it gets cut down. After which, of course, it will be the owner's problem, and no longer feature into the manufacturer's considerations.

I believe the threadless is a tad mechanically superior. I've had two quill forks fail just at the beginning of the thread, but I've never seen a threadless fork fail mid-shaft.

The argument that quill stems can be adjusted for height any time is true but not as important as it seems. The vast majority of riders set their bar height once and never change it.

A threadless steerer can be cut slightly long and a spacer installed above the stem to allow a future height increase if desired. I cut mine to allow a 10 mm spacer above the stem but have never had to remove it to raise the stem. Lowering the stem is, of course, easy. Just move some spacers around and cut the steerer only after you are sure that's where you want the bars.

As noted there are two advantages to threadless:

1. Weight reduction as the steerers can be made of Al alloy or carbon and a threadless stem is significantly lighter than a quill stem

2. Simplicity for fork and bike manufacturers. They inventory one fork length and it fits everything. All forks are made with the same length steerer (long) and the forks are cut to length to fit for various frame and headset requirement.

Does anyone have pics or diagrams that would illustrate the difference between threadless and quill?


http://www.sheldonbrown.com/gloss_ha-i.html#headset

Keep in mind, it's really the fork steerer tube that's threaded or not. That determines whether you use a quill stem that goes down into the steerer and has the headset threaded onto the top of the steerer tube, or a threadless steerer that has the stem clamped to the top portion of the steerer tube. With threadless, a star spangled nut (installed inside the threadless steerer tube) is necessary for the top cap bolt on the headset to screw into, which preloads the headset bearings.

On a fast and nimble road-bike, I go with 1" threaded and won't change that. Adopt it for 1-1/8" stems - yes. But nothing will get me to abandon my Tange Levin headset.

For hybrids I prefer the threadless. They just feel right for these bikes. Mountain-bikes, too.

But nothing will get me to abandon my Tange Levin headset.
What got me to abandon my two OEM Tange Levin headsets was "brinelling" of the crown race and lower cup in less than 4000 miles. And, yes, these headsets were properly adjusted, lubricated and kept relatively clean and used on road bikes.

A Shimano 600 (loose bearing version, not the newer cartridge bearing model) replacement headset lasted over 15,000 miles on the same bike.

I've never had a problem on god-only-knows how many miles. But I bought it in 1982, and the same headset is still available today - for about double the price of then. If the Shimano 600 works for you - go for it. If my Tange dies on me - I'll take a look at the Shimano. Thanks!

I added the threadless adapter to my Kestrel mainly so I could have more options for sizing and comfort. I really like being able to change up and it really does'nt look that bad to me..Very functional..Here's a before and after..I know I'll hear it---"FLIP THE STEM"...but it's where I like it...

I've always considered the headset's fine threads and limited amount of engagement to be a real weak link. Using aluminum to save weight makes it even worse. Also, adjusting threaded requires expensive wrenches that have no other use.

Think about how many "stuck stem" posts we get here; yes, those are older bikes but I expect this won't occur with threadless since the wedge has been eliminated.

I think threadless is a huge improvement.

brandenjs -

I think we're on the same page! LOL. Anywho, I also did a conversion - keeping my Tange Levin. Sorry for the poor photography:

http://i424.photobucket.com/albums/pp323/nagognog/IMG_0013.jpg

Here's a before and after..I know I'll hear it---"FLIP THE STEM"...but it's where I like it...

I am usually a fan of the looks of quill stems, but if I had one that looked like your original, I would have replaced it too. ;)

Seriously though, how is the threadless adapter working out as far as stiffness etc? Do you recall which model you bought?

Mine is a Profile Design stem-converter. It's totally solid - as is the Ritchey adjustable stem. Can't tell it's a 2-piece stem unless you look at it.

Threadless solved the problem of being able to adjust your handlebar height, and even made bikes uglier as part of the bargain. :beer:

Does anyone have pics or diagrams that would illustrate the difference between threadless and quill?

Threadless:

http://i276.photobucket.com/albums/kk18/melvillelgz868/threadless.jpg

Quill:

http://i276.photobucket.com/albums/kk18/melvillelgz868/quill.jpg

Both on track bikes. There was about 150 g weight savings, but the quill bike was not using the lightest stuff. The bigger benefit was the more rigid handlebar--almost like a traditional steel bar/stem but at least a pound lighter.

I've always enjoyed the ability to fine tune how high or low I want my handlebars, and it's a lot easier to do that with a conventional quill stem. As for failing, I've never had a stem fail since I was a teenager, and I'm 55 now. Threadless may be more "mechanically simple", but it's also more "user complicated", not to mention that it makes every road bike look like an 1990's mountain bike. Even a Richard Sachs road frame is horribly disfigured by one of those contraptions.

And let's not exaggerate... Some of my quill stems have been ones that use a simple wedge, and some have been the more high-quality ones that use an expander. The simple wedge ones don't need a hammer or anything to be loosened other than your allen key, and the cone expander ones only need a small tap on top with the handle of a pedal wrench or even just the larger key in an allen key set.

I've never liked hybrid things that combine functions. Threadless is a kludgy design that combines the stem and the bearings and needs both to work. They took off in the racing world because of stiffness... needed by the modern, extra large, steroided cycling athlete. In the consumer world, they are there to save manufacturing the trouble of making and distributing different length of forks, and I suppose also for people who are really too big and heavy to be riding fine road bikes in the first place.

Of course now that I'm older and wiser I know to just get a bigger hammer :)


The gentler approach is always best!!!

I am usually a fan of the looks of quill stems, but if I had one that looked like your original, I would have replaced it too. ;)

Seriously though, how is the threadless adapter working out as far as stiffness etc? Do you recall which model you bought?

You are right, that quill stem just did'nt seem like it went with the style of the bike. Also it was a bit long for me. I actually could use a shorter one than the one that is on there, but I can ride comfortable for many miles so I'll leave it. It is plenty stiff. I have'nt noticed any difference at all. This is the link for it from E-bay..

http://cgi.ebay.com/Stem-Adapter-converts-1-Or-1-1-8-Quill-to-Threadless_W0QQitemZ270286170803QQihZ017QQcategoryZ42336QQssPageNameZWD1VQQrdZ1QQcmdZViewItemQQ_trks idZp1638Q2em118Q2el1247

You people realize you've been answer and replying to stuff that is fully 7 years old right?