I recently got my first new bike in about 10 years. It's a Jamis Quest which I love. It's got a threadless headset. I've taken apart many of the old style (quill?) headsets but I'm a little scared of this one.

Can anyone point me towards an exploded diagram of a threadless headset or a detailed description of how they work/ how they differ from the older style? Thanks.

They actualy are amost simpler then the threaded ones you used to work on. Main difference is on top you don't have a part that threads down on the fork.
Check out the barnett manual posted at the top of this forum. Depending on who makes your headset, some have complete breakdown diagram of their headset.
For example Chrisking - if you scroll down and download the PDF for their no threadset.
https://www.chrisking.com/tech/tech_PDF.html

Chapter 11 of Barnett's Manual (click here) covers headsets and includes a section on that newfangled threadless kind. Adjusting and service a threadless headset is a breeze compared to the old quill type.

That was helpful, thanks guys. I've got a couple of other questions:

• What are the pros/ cons of threadless headsets vs the old kind?
• It seems that raising or lowering my handlebars is not as simple with a threadless headset - what does it take to raise or lower the bars?
• What is the deal with those spacers beween the stem and the headset?

Thanks again!

Pros/Cons.. Threadless is lighter and supposedly a bit stronger..

Now to raise and lower, you basicaly have to replace yoru stem or get a adjustable stem. FOr a sever change you can get extender for the fork steerre so you can mount the stem higher. This is the main drawback to threadless.
The spacesr is used to raise the stem, since resting right on the headset is normaly not the most comfortable position for alot of people.

Like Kev: the pros are lighter weight and greater strength. Another pro is the ability to adjust the headset with a single allen key.

The biggest con is that you cannot raise and lower the stem easily. The spacers do give you some adjustability up and down, however. If you need to lower your handlebars, take some spacers out from under the stem and put them on top. To raise the stem, do the opposite.

A lot of bikes come new with no spacers on top of the stem. For my 2 cents worth, this is a bad idea, unless you have been very carefully and well fitted to the bike.

There are steerer extenders for threadless headsets designed for people who wish to raise their bar height, but I personally wouldn't trust my safety to one of those things. Otherwise, you may be able to slide your stem up and down the steerer a bit, if there is enough showing. You could also buy a riser stem, and some people even turn the common 73 degree stem upside-down to achieve this.

As far as advantages go, most of them are for the manufacturer (fewer parts, no expensive threads to machine...), or for the retailer (quicker to assemble, especially by ham-fisted seasonal help). Aside from the weight savings with either ultra-thin or CF steerers, I dobt there is any performance advantage to a threadless headset system.

In short, the threadless system is cheaper for the manufacturers. It's an inelegant design and there are no real advantages.

Stem height adjustment restrictions aside (and since most of us set it once and leave it alone, that's maybe not as big a deal as it's sometimes made out to be), the threadless system is arguably the more elegant of the two: simple and easy to adjust for bearing preload without the need for specialty headset tools, less prone to damage from accidental overtightening, etc.

Plus, almost all of my bikes with threaded headsets have eventually exhibited bearing surface wear that makes the bike a little harder to steer. None of my bikes with threadless headsets have that problem. Don't know if the improvement in a consequence of the threadless design per se or if it's because the threadless headsets are all 1 1/8" and the threaded are all 1", but there it is.

1. )

https://bicycletutor.com/adjust-threadless-headset/

2.)

https://www.parktool.com/repair/readhowto.asp?id=65

Take your time and read.

Have fun!

Oh yeah - link is busted. Both of them.

100% nonsense.

Please stop spouting this ignorance. https://www.sheldonbrown.com/brandt/t...s-headset.html

Operator, as adults we can have a difference of opinion but there's no need to be rude about it.

Please learn to accept that the other person's view has some validity, there is very little in the world that is 100% right or 100% wrong. The more I learn, the more I have learnt that there are always shades of grey.