ZS44/ZS56

Product Details

Stylish, durable, and easily serviceable.  Those were the goals when designing our headsets.  We machine engrave our logos for a classy look, use durable and easily replaceable Enduro stainless steel angular contact bearings, and use a "split" crown race design that you can install and remove by hand. The ZS44│ZS56 headset is designed to fit frames with tapered 44mm top/56mm bottom head tubes and tapered 1-1/2" (40mm) fork steerers.  But nowadays with all the different headset standards available we needed to get specific so check the SHIS specs below.  SHIS?  Yep, that's the "Standardized Headset Identification System" used to verify compatibility.

Specs

• 6061-T6 aluminum
• Machine engraved logos 
• Easily replaceable Enduro stainless steel angular contact bearings
• “Split” crown race for tool-free installation and removal
• Stack height
  • Upper: 8mm
  • Lower: 4mm
• Weight

Compatibility

• A perfect match to our really sweet matching headset spacers, available separately
• The ZS44│ZS56 headset is designed to fit frames with tapered 44mm top/56mm bottom head tubes and can accommodate tapered 1-1/2" (40mm) fork steerers
• The “ZS” stands for “Zero Stack” as the section of the cup that houses the top bearing sits inside of the frame’s head tube.  The “44” stands for the 44mm “skirt” that presses into the top of the head tube, and “56” stands for the 56mm “skirt” that presses into the bottom of the head tube
• SHIS specification
  • Upper: ZS44/28.6
  • Lower: ZS5640
• Not compatible with carbon forks that have integrated crown race seats
• SHIS definitions on the Park Tools website: here
• Frame/Fork specs:

Frame upper head tube inside diameter	43.95mm to 44mm
Frame lower head tube inside diameter	55.9mm to 55.95mm
Fork steerer diameter top section	28.45mm to 28.6mm
Crown race seat diameter for “tapered 1-½”	39.79mm to 39.85mm

Bearings

Headset Model	Upper Bearing (inner/outer angle)	Lower Bearing  (inner/outer angle)	Lower Fork Race Compatibility
ZS44│EC44	ACB3645SS 36/45	ACB6808CCSS 36/45	1-½” (40mm)

What's in the box

• One headset which includes:
  • Top cap bolt
  • Top cap
  • Bearing cover
  • Upper bearing compression ring
  • Upper bearing
  • Upper cup
  • Lower cup
  • Lower bearing
  • Crown race
• Headsets no longer include Star Nuts due to the Earth's star nut overpopulation crisis. If you need one, they are available separately here.

FAQ's

• Will this headset fit my bike?
  • You will need to do some homework and get the SHIS specs of your frame and fork which those manufacturers will have.  See those definitions here.  Also see the "Compatibility" section on this page.  Simply telling us what model bike you have may not be enough info to go on.  Help us help you and get the specs!