This is a high - performance bottom assembly only. Its technical details are as follows: ZS/56/40/H4/K. It has a ZS - ZeroStack bottom type. The inside diameter of the bottom head tube is 55.95mm, and the seat diameter of the crown race is 39.79mm. The crown race is made of durable steel. The face - sealed bottom stack height is 4mm, and the bottom bearing type is black oxide. The sealed material is 6061, and it weighs only 65g. The part number is BAA0090K. The all - new 40 - Series is the star in Cane Creek's headset line - up. It combines all the features needed for a durable, lightweight, and long - lasting headset, offering the perfect balance of performance, durability, and value. Precision engineered in Fletcher, NC. Key features include 6061 - T6 aluminum cups and covers that are internally relieved to cut weight. The innovative Clip - Seal seals the top assembly and holds the compression ring, reducing loose parts. High - quality, low - friction face - seals are on the crown races. The durable steel crown races and dependable black - oxide, sealed cartridge bearings ensure long - term use. There are tall and short aluminum and carbon covers available for many IS and ZS models. It's Interlok spacer compatible, and internal parts are cross - compatible across the 10, 40, and 110 - series with consistent stack heights. It uses a ZeroStack Top Assembly and a Traditional Bottom Assembly.

Using this Cane Creek bottom assembly is straightforward. First, make sure your bike's frame is clean and free of debris before installation. Align the assembly properly with the head tube and the crown race according to the given dimensions. When installing, handle the parts gently to avoid any damage, especially the bearings and seals. For daily use, keep your bike clean and dry to prevent dirt and moisture from getting into the assembly. If you notice any unusual noises or looseness during riding, check the assembly immediately. To maintain it, periodically clean the external parts with a soft cloth. You can also lubricate the moving parts with a suitable bike lubricant, but be careful not to over - lubricate as it may attract dirt. When storing the bike for a long time, keep it in a dry place to prevent rust and corrosion.