CANE CREEK 40 SERIES HEADSET BOTTOM The 40-Series sets the standard for performance, durability and value. Drawing from the Premium 110-Series Design, the 40-Series incorporates all the features necessary for a durable, light-weight, long-lasting headset. To make it easier, we developed consistent graphics, interchangeable parts and over 40 configurations to meet almost every need. Sold in straight and tapered assemblies or tops & bottoms, Cane Creeks 40-Series offers the largest fitment range of any headset line on the market. Precision engineered by Cane Creek in Fletcher, NC. The Cane Creek 40-Series IS52 Bottom Headset fits 1.5 Integrated headtubes and 1.5 steerer tubes.