CNC 1-1/8in Threadless Bike Headset Straight Tube 44mm — Double-Sealed Bearings, 6061-T6 Aluminium

This headset is a replacement and upgrade option built from forged 6061-T6 aluminum with CNC machining and double-sealed bearings. It fits frames with common ZS head tube inner diameters and works with straight 1-1/8" forks or tapered forks with the right lower cup. The pre-lubricated bearings and tight sealing reduce contamination and deliver precise steering feel over long rides.

How do I know this headset will fit my bike?

Measure your head tube inner diameter and your fork's upper and lower outer diameters before ordering. The CNC headset is available for several ZS frame sizes and supports straight 1-1/8" forks and tapered forks when paired with the correct cup configuration.

• Compatible head tube inner diameters: ZS 34mm, 44mm, 41.8–52mm, 44–55mm, 44–56mm
• Fork upper outer diameter: 28.6mm (standard 1-1/8")
• Fork lower outer diameters supported: 30mm or 39.8mm depending on tapered option
• Check the product drawing or ask support if measurements are unclear

What performance improvements will I notice after installing it?

The combination of CNC precision and double-sealed, pre-lubricated bearings reduces play and makes steering smoother. Riders often notice crisper handling, less wobble at low speeds, and improved durability thanks to corrosion-resistant materials and better sealing.

• Pre-lubricated bearings for immediate smooth operation
• Double seals keep grit and water out, extending bearing life
• Forged 6061-T6 aluminum body for stiffness and low weight
• CNC machining for tighter tolerances and reduced steering slop

How difficult is installation and what tools do I need?

Installation is straightforward for anyone comfortable with headset swaps, though it requires the correct press-fit tool for cups and a crown race driver for the fork. If you lack a headset press, many bike shops will perform a clean, efficient install for a small fee.

• Required: headset press or shop service for cup installation
• Required: crown race setter and torque wrench for the top cap and stem
• Helpful: grease for contact surfaces and a clean workspace
• Follow frame/fork dimensions carefully to choose correct model

Who is this headset for? CNC's 1-1/8" semi-integrated, double-sealed headset suits riders restoring vintage bikes, upgrading tired steering systems, or building reliable commuter and off-road builds. It's aimed at cyclists who want a durable, low-maintenance headset with precise bearing guidance and corrosion-resistant aluminum construction. If you prefer long-lasting performance, smoother steering, and the option to use a straight or compatible tapered fork, this CNC headset is a practical replacement part. Always confirm your frame and fork measurements before purchase, and contact support for measurement help or fit questions.