is that a 1" head set?
there are 2 1" standards, the JIS and the more common European standard
The JIS head sets have a 27.0mm crown race and 30.0mm cups. The European standard 26.4mm crown race and 30.2mm cups. So a JIS cup would fit too loose in a standard head tube.
Carsten
One-inch Japanese Industrial Standard (JIS)
Common on many Asian manufactures bicycles, both road and MTB
Fork column outside diameter- 25.4mm (1")
Head cup race OD- 30.0mm
Acceptable head tube ID range- 29.75mm to 29.9mm
Fork crown race ID- 27.0mm
Fork crown seat OD acceptable range- 27.1mm to 27.2mm
Stem diameter at quill- 22.2mm
One-inch "Modern European" Standard
Many road bike and some MTB bikes
Fork column outside diameter- 25.4mm (1-inch)
Head cup race OD-30.2mm
Acceptable head tube ID range- 29.9mm to 30.1mm
Fork crown race ID- 26.4mm
Fork crown seat OD acceptable range- 26.5mm to 26.7mm
Stem diameter at quill- 22.2mm