Black bearing bearing headset 40 × 52 × 12 mm 45° / 45° HB-D4

BLACKBEARING D4 headset bearing – 40 × 52 × 12 mm (45°/45°)

The BLACKBEARING D4 is a high-quality sealed cartridge headset bearing designed for modern bicycle steering systems. Its precision construction, low friction, and reliable sealing ensure smooth steering performance, accurate handling, and long service life.

Key features

• High-quality BLACKBEARING headset bearing
• Sealed cartridge construction
• 45°/45° angular contact design
• Low rolling resistance
• Strong protection against dust, mud, and moisture
• Chrome steel races and balls
• Precision-ground surfaces for smooth operation
• Durable grease for long-lasting performance
• Designed for modern integrated headset systems

Technical specifications

Compatibility

• Headset systems requiring a 40 × 52 × 12 mm bearing
• 45°/45° angular contact headset standards
• Specific integrated headset systems only
• Always verify exact dimensions and angles before installation, as headset bearings are not universally interchangeable

In practice

• Ideal replacement for worn or damaged headset bearings
• Provides very stable and precise steering feel due to increased width
• Sealed design protects against contamination
• Durable construction ensures long service life
• Suitable for road, gravel, MTB, and e-bike applications