Naive question: I am new to bikes (building them anyways) but want to build a training bike (single-speed). I ordered a Cinelli Superpista frameset with a 1 inch threaded fork. Could you please explain the differences to me of a threaded and a threadless headset? I don't have the frame yet and that might help but could I use either Campy headset on the frame (threaded or threadless?)? Is the threaded headset for quill stems and the threadless for the other style with separate stem attaching to handlebars?
Thanks for any response
Paul

pbien@triusrx.com

"Is the threaded headset for quill stems and the threadless for the other style with separate stem attaching to handlebars?
Thanks for any response" --pbien

Yes, although adapters can be used to mount a threadless style stem into a threaded fork.

Take a look here https://sheldonbrown.com/headsets.html .

Brad

If the fork is threaded you must use a matching threaded headset. There are many manufacturers still making threaded headsets and 1" is still a common size for them Based on your Italian frame you will need an ISO size headset. The alternative is a JIS size which was common only on older Japanese bikes. These two types work exactly the same but there are minor dimensional differences so get the correct one.

A threaded headset has the upper race screw onto the threads of the fork's steerer tube and hold the entire assembly together. A threaded locknut then goes down over the top race to hold the adjustment in place.

A threadless headset requires a fork with a longer and smooth steerer tube. The top race just slides down over the top of the steerer and the stem slides on similarly. Once the headset's adjustment is correct, the stem's clamp bolts hold the adjustment in place.

Typically a threaded fork uses a quill stem but there are "quill to threadless stem" adapters which allow a threadless-style stem to be used.

Look at Park Tools web site for a good tutorial on headset installation and adjustment. BTW, headset installation is one job I normally recommend even reasonably experienced bike mechanics leave to their local bike shop. Done properly it requires several specific tools that aren't worth buying (or making) unless you do this job often.

I have come to appreciate the ease of use with threaded headsets. They make bar height adjustments simple, and with an adjustable stem, height and reach can be fine-tuned easily.

I have threadless on some bikes too, but it is a bit more challenging to fine-tune them.

This is correct but can easily be worked around. There are adjustable threadless stems so the ability to reset the height and reach to the bars is available in threadless.

The main thing is to initially leave the fork steerer longer than you think necessary and use spacers above the stem. You do several rides while playing around with the stem's position until you finalize it. Then you cut the stem to the final height and, preferably, leave it long enough to still require a 10 mm or so spacer above the stem. For most riders, once the bar position is establshed, it won't be changed for a long time but the adjustable stem and top spacer give you some wiggle room if needed.

BTW, most quill stems have a limited range of height adjustment so they are not really much better than a threadless setup.

I agree that it can be done with threadless, but is a bit more challenging. The stem I pictured has about 3" of height adjustment, and can go from -10 to 90 (straight up). This makes it easy to fine-tune the bars for a particular ride, or reset if I feel like trying something different. I have adjustable stems on a couple of my threadless stems, but the height adjustment takes a lot more effort. Not impossible, just inconvenient.