[abbike18]

I have a frame which currently uses a traditional headset with press in cups and loose ball bearings. Do the zero stack headsets fit in the same headtube, or are they only for special headtubes? If they do not fit, does anyone know of a really low stack height traditional headset?

Thanks
Alex

 

[zebrahum]

Cane Creek says "The Zero Stack design offers a low stack height and the security of bearing cups that are hidden inside the head tube. ZS cups are compatible only with specifically machined head tubes and cannot be retrofitted to an existing bike with Traditional headset cups."

I can't speak for other headsets, but the ZS won't work.

This thing is crazy low for a traditional headset
http://www.canecreek.com/component-headsets?browse=type&type=traditional&cat=1-1-8-threadless&product=aer-Traditional
(be aware, it's a road headset)

Otherwise, there's a few options you can find around 27mm stack for not a lot of money. You can also get a bunch of lower stack stems as well.

 

[crohnsy]

http://crankbrothers.com/directsets_cobaltsl.php

crank bros is another option about 1 mm taller than the cane creek though..

 

[aj-monkey]

Is the stack height of a headset the measurement of the visible portion of the headset cups, both top and bottom? For some reason I only ever thought that it was the upper cups measurement but I think that is the wrong thought process?

 

[zebrahum]

Is the stack height of a headset the measurement of the visible portion of the headset cups, both top and bottom? For some reason I only ever thought that it was the upper cups measurement but I think that is the wrong thought process?

The measurement the companies use is the visible height. It is provided so you can measure your stem + your headset and see how many spacers you'll need, or if it'll fit at all.

 

[abbike18]

I ended up getting a crank bros iodine headset. I think they are about the lowest stack height you can get, sans getting a road headset. They use a unique design in which the cup of the sealed bearing is actually the headset. Think of it as the entire headset assembly is like a large sealed bearing. The upside to this is light weight and low stack height. The downside is you can't change the bearing, you have to change the entire headset.