This style is often referred to simply as an “1-⅛” headset which, most of the time, is enough of a description to get you the correct headset.  But nowadays with all the different headset standards available we needed to get specific.

The EC34│EC34 headset is designed to fit frames with straight 34mm/34mm head tubes and straight 1-⅛” (28.6mm) fork steerers.  The “EC” stands for “External Cup” meaning the section of the cup that houses the bearing sits outside of the frame’s head tube and the “34” stands for the 34mm “skirt” that presses into the frame.    

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
• Compatible with Ritchey carbon 1-1/8″ steerer forks with integrated crown races (not tapered steerer forks)
  • Must purchase additional bearing part #ACB45451125TSS (Parts>Headset Parts) which replaces the stock bearing and crown race
    • WCS road SKU 34356117005
    • WCS road SKU 34356117006
    • WCS Adventure Gravel SKU 34556117012
    • WCS Gravel Cross SKU 34556117010

Specs 

• SHIS specification
  • Upper: EC34/28.6
  • Lower: EC34/30
• Stack height
  • Upper: 15mm
  • Lower: 12mm
• SHIS definitions on the Park Tools website: here
• Frame/Fork specs:

Bearings