The Marwi Union CB-715 headset bearing (30.15 x 41 x 7 mm, 36°/45°) is a high-quality sealed cartridge bearing designed for 1"1/8 headsets on road bikes, MTB, gravel and e-bikes. Manufactured to ABEC-3 standards, this bearing guarantees smooth and durable rotation of the steering pivot, with optimal sealing against water and dust infiltration. Compatible with virtually all frames and forks incorporating this dimension, it is the ideal replacement part to restore precise, play-free steering.

Technical design and premium materials

The CB-715 benefits from careful manufacturing resulting from collaboration between Marwi and four major global bearing specialists. The inner and outer races are machined from CrMo steel (Chrome-Molybdenum), a material renowned for its wear resistance. The balls, also made of hardened CrMo (HRC 61-66), ensure low-noise, long-life performance. The nylon cage lightens the assembly while maintaining the balls with precision. Finally, the LLU rubber seals (full contact, 2RS type) create an airtight barrier against external elements, extending the bearing's longevity even in difficult conditions.

High-performance grease and ABEC-3 standard

• Multemp SRL grease (Kyodo Yushi): premium grease that guarantees quiet operation, low rolling resistance and excellent durability over time.
• ABEC-3 tolerance: precision commonly specified by renowned bicycle manufacturers, ensuring precise adjustment and reliable performance.
• 2RS double protection: both rubber seals (LLU - full contact) effectively block water, mud and dust infiltration, even during rides in wet or dusty conditions.

Dimensions and universal compatibility

With an internal diameter of 30.15 mm (sometimes also designated 30.2 mm depending on sources), an external diameter of 41 mm and a thickness of 7 mm, the CB-715 fits on 1"1/8 pivot headsets. Its contact angles of 36° and 45° suit many integrated or semi-integrated headset geometries. It replaces original bearings specified by most major frame brands (road, MTB, gravel, e-bikes) on a like-for-like basis.

Installation and maintenance

• Removing old bearings: use a suitable puller or bearing drift to cleanly remove worn bearings without damaging the cups.
• Cleaning contact surfaces: thoroughly degrease the bearing seats in the cups to ensure perfect fitting.
• Installing new bearings: gently press the CB-715 with a press or installation tool, taking care not to force on the fragile races or seals.
• Additional greasing (optional): although pre-greased, applying a little quality white grease on the external surfaces improves sealing and facilitates installation.

Key features of the Marwi Union CB-715 bearing

• Universal compatibility: replaces original bearings on the majority of 1"1/8 headsets with 36°/45° angles.
• OEM quality: manufactured to the same specifications as bearings fitted as original equipment by major bicycle manufacturers.
• Reinforced sealing: LLU rubber seals (full contact) double-sided for maximum protection against water, mud and dust.
• ABEC-3 precision: strict manufacturing tolerance, guaranteeing precise adjustment and smooth, play-free rotation.
• Longevity: hardened CrMo materials HRC 61-66 and Multemp SRL high-performance grease for extended service life.
• Low friction: smooth and quiet bearing, preserving riding comfort and steering responsiveness.
• Exceptional value for money: OEM performance at a very affordable price for maintenance and repair.

Marwi Union brand: tradition and global expertise

Marwi, whose roots date back to 1899 in Germany (foundation of Wilhelm Feuerhake in Fröndenberg), is today an international group leading in the manufacture of bicycle components. With production sites in Taiwan, Indonesia, Czech Republic and the United States, and an R&D center in Germany, Marwi employs approximately 1,000 people and produces more than 30 million pairs of pedals and 6 million saddles per year. Under the Union brand (famous in Europe and the United States), Marwi distributes a complete range of 159 different bicycle bearings, covering all applications (hub, bottom bracket, headset, pedals, suspension pivots). Union bearings are manufactured in partnership with four major global bearing specialists, guaranteeing OEM quality and perfect compatibility with cycling industry standards.