Imprecise spacers can cause your headset to loosen affecting bike handling and component life lightweight and precisely parallel zipp carbon headset spacers are precision ground to keep your fork secure through every twist turn and bump in the road 1 18 diameter in 4 8 12 and 30 mm heights key features zipp carbon headset spacers are precision ground to keep your fork secure through every twist turn and bump in the road imprecise spacers can cause your headset to loosen affe