This weekend, I went for a 2-hour ride to see how my new Aer headset performed and I was quite pleased. The Cane Creek Aer ZS or Zero Stack™ is somewhat different from other headsets, as its upper runs on a NorGlide® bushing. Initially, I'm always a bit skeptical, although that never held me back from experimenting with new stuff. On a sidenote: The Aer is designated as "ROAD ONLY" or warranty will be void.Description/Specs
As seen in my earlier post, the Cane Creek Aer ZeroStack, without nut/expander or top cap, weighs 50g. This matches the weight specified by Cane Creek. Incomparison, an Extralite Scalhead weighs about 52g including top cap and expander.
Total stack height is less than 10.5mm, divided amongst a 7.2mm upper and 3.3mm lower. The headset is so light because it uses only one bearing (bottom), which happens to be the same as in the high quality Split-Lip Black Oxide bearing found in Cane Creek's 110-series headsets.
The top part spins on an angular bushing from a self-lubricating material called Norglide®, essentially a sandwich composite made from PTFE/teflon and metal. It's manufactured by Saint-Gobain Plastics. The bushing runs directly onto an angular surface in the top cup, also with the 33g integrated version, albeit that the integrated cup drops into where ordinarily the bearing would sit.
The cups have distinct cutouts on the outer surface to make them lighter. Cane Creek states that the Norglide bushings should last at least 450 hours or between 2000-3000 miles. It should be easy to obtain a replacement Norglide bushing through a dealer or directly via Cane Creek.Installation
The frame it went into was my Scott Addict, which came with a Ritchey WCS Zero semi-integrated headset. When I removed it, I didn't have any problems with the cups. I did have a hard time getting the base plate off, as there was nowhere I could get any tools under, except a really sharp screwdriver. Luckily, the base plate of the Cane Creek Aer is slightly easier to remove, e.g. in case a change of fork is desired.
The cups were easily pressed in, and 5 angled notches on each cup were very helpful to align them as straight as possible.Adjustment
Because this headset doesn't have run entirely on bearings, it's very important to run the correct "bushing pre-load". You can easily overtighten this headset, which in turn might reduce service life. Too tight and the bars are hard to spin. Too loose and there is noticeable movement in the headset. As a result, you may have to play a bit to elimininate headset play. The headset manual says that (partly because of the NorGlide® upper) the Aer needs about 100 miles/160km of break-in period before it runs smoothly.Overall Impression
I have a very good feeling about this headset. Not only does it look better than the Ritchey WCS it replaced, the lower bearing is solid and feels similar to a Chris King headset. The top part is obviously constructed to reduce weight, and this is the primary goal of this headset, to shave unnecessary weight. The most important thing about this headset is that it works without unwanted surprises at a weight that's very attractive.
More information can be found on the Cane Creek website