Our colleague Drew found that the aesthetics of Aheadset equipped bikes was compromised when there was a mismatch of the thickness of the headset spacer and the clamp of the stem, which would result in a shoulder between the spacer stack and the stem. So he made it his mission to find spacers that were thinner walled than the standard alloy ones (or carbon fibre ones, which were worse). The quest ended when we sourced these alloy Cinelli spacers. And there was much rejoicing.