Specifications:

• This headset will allow you to alter your top-tube length by +/- 6mm.
• Fits headtube internal diameter: Upper - 56mm: ZS56
  Fits headtube internal diameter: Lower - 56mm: ZS56
• Upper cup insertion depth: 11.5mm
  Lower cup insertion depth: 11.5mm
• Upper cup Stack height: 3.5mm - Total upper stack height including bearing cover: 9.5mm
  Lower cup Stack height: 3.5mm
• Upper Bearing: 41mm OD, 45 x 45 Degree AC sealed bearing
  Lower Bearing: 52mm OD, 45 x 45 Degree AC sealed bearing
• To suit standard 1 1/8" forks.
• Proudly machined in the UK, anodised locally in black from 6082 T6 aluminium.
• Split type 7075-T6 aluminium crown race for simple, tool free installation
   

Headset comes complete with top-cap (star-nut included), bearings and crown race - all parts required for fitment.Simply order the correct headset from the list of available head tube lengths below, if your frames head tube length is not listed please contact us.

We use the 'SHIS' standard to label our headsets - the numbers refer to the internal diameter of the headtube and the letters refer to the type of headcup: EC = 'External Cup' and ZS = 'Zero Stack' - For more SHIS info please refer to the Park Tools information page - Standardized Headset Identification System | Park Tool