The Cane Creek 110-Series Mixed Tapered ZS44 EC49/40 Headset has a zero stack (ZS) top cup that places the bearings inside the confines of the head tube. At the bottom, the lower assembly is a traditional style (TR) with the bearings housed outside the head tube.
The 110-Series Mixed Tapered Headset begins life when they machine the cups from custom drawn, US made seamless 7075 aluminum tube. Each part has been relieved of excess material, inside and out, to keep the weight to a bare minimum while retaining the strength you'll depend on. These cups house the stainless steel sealed cartridge bearings, both of which use Cane Creek's proprietary split-lip seals to keep the grease in and contaminants out.
At the same time, these seals run smoothly against the races with a minimum of drag so your steering feel will be rock solid, yet will respond to the lightest touch on the bars. It's quite possible that dirt and muck will never even reach the bearing seals anyway. The 110 Headset includes low-friction seals on the top bearing cover and on the crown race that effectively seal the cup and bearing contained within.
Another advantageous detail of the 110 is the captured compression ring under the top bearing cover. It facilitates easy assembly and eliminates the possibility of rocking or creaking regardless of the small variations often found in steerer tube diameters. And for lightweight carbon fiber steerer tubes, the extra surface area over other systems ensures a damage-free compressive junction. All these technical details aside, you may simply lust for the jewel-like quality of the 110-Series Headset due to its highly polished finish or its rich anodized colors. And that's perfectly fine too.
The Cane Creek 110-Series Mixed Tapered Headset is designed to mate a fork with a 1-1/8" - 1.5" tapered steerer to a tapered head tube having a 44mm I.D. on top and a 49mm I.D. on bottom. It's available in Black and Red.