The ZS44│ZS56 headset is designed to fit frames with tapered 44mm/56mm head tubes and works with tapered 1-1/2” fork steerers.  The “ZS” stands for “Zero Stack” as the section of the cup that houses the bearing sits inside of the frame’s head tube.  The “44/56” stands for the top/bottom diameter of the “skirt” that presses into the frame.

Note: As of 9/14/23, headsets will no longer include Star Nuts due to the Earth’s star nut overpopulation crisis. If you need one, they are available separately .

Features

• U.S. sourced 6061-T6 aluminum
• Machine engraved White Industries logos 
• Easily replaceable Enduro bearings
• “Split” crown race for tool-free installation and removal
• Really sweet matching headset spacers available separately
• Can accommodate “tapered 1-1/2” forks with a 40mm crown race seat

Specs 

• SHIS specification
  • Upper: ZS44/28.6
  • Lower: ZS56/40
• Stack height
  • Upper: 8mm
  • Lower: 4mm
• SHIS definitions on the Park Tools website: