The FSA TH MR136 headset bearing represents technical excellence for integrated 1-1/4" headsets. Designed with ACB (Angular Contact Bearing) technology in 45°x45° configuration, this bearing offers optimal resistance to axial and radial loads, ensuring precise, smooth and durable steering in all riding conditions.

Technical Overview

The MR136 bearing (reference NO.51) stands out as the preferred replacement solution for TH and FSA headsets fitted to many modern frames. Its precise dimensions of 32.8 x 41.8 x 6 mm and double 45° contact angle ensure perfect integration in head tube cups machined to the Campagnolo standard, while offering compatibility with Giant Overdrive 2 systems. Weighing only 26 grams, it combines lightness and robustness.

ACB (Angular Contact Bearing) technology for performance

• Optimized 45°x45° configuration: The two 45° chamfers (internal and external) allow ideal distribution of axial and radial loads, superior to conventional single radial contact bearings
• 60 CrMo steel balls: High number of Chrome-Molybdenum steel balls ensuring maximum contact surface, ultra-smooth rotation and exceptional longevity
• SUJ2 steel rings: High-performance bearing steel (Japanese standard) offering superior hardness, excellent fatigue resistance and precise dimensional tolerances
• Black sealed joint: Effective protection against water, mud and external contaminants while retaining lubrication grease for long-lasting operation

Compatibility and Applications

• 1-1/4" (31.75 mm) steerer standard: Designed for 1-1/4 inch diameter fork steerers, a widespread standard on tapered and oversized configurations
• Compatible headsets:
  • FSA Orbit NO.51, NO.54 (upper part)
  • TH Industries integrated systems
  • Campagnolo Hiddenset IS42 45/45° standard
  • Giant Overdrive 2 headset
• Bike types: Road, Gravel, XC/Trail MTB, cyclocross — all bikes equipped with 1-1/4" forks and head tube cups machined at 45°

Advantages of Double 45° Angular Contact

The 45° angle on both bearing faces has become the universal modern standard in integrated headsets. This configuration offers decisive advantages over older 36° standards or radial contact bearings:

• Multi-directional load management: The angular contact simultaneously supports vertical loads (rider weight), horizontal loads (braking, cornering) and torsional forces, essential in dynamic riding
• Increased steering rigidity: Less deformation under stress = better trajectory precision and optimal feedback
• Maximum durability: Uniform stress distribution over the entire contact surface, reducing localized wear and extending service life
• Adaptation to modern frames: Compatibility with head tube cups machined to current standards (SHIS — Standardized Headset Identification System)

Installation and Maintenance

• Assembly: Installation by press-fitting into the head tube cup machined at 45°. Use a suitable press tool to avoid damaging the bearing. Apply generous grease before assembly
• Orientation: Respect the installation direction: the black sealed joint must face outward to ensure optimal protection
• Inspection: Regularly check for absence of play in the headset and smoothness of rotation. A worn bearing generates creaking or stiff steering
• Preventive replacement: Replace bearings every 2 to 3 years under intensive use, or as soon as play or roughness appears

Why Choose an Original FSA Bearing

FSA (Full Speed Ahead) is a leading global manufacturer based in Italy (Milan) and Taiwan, sponsoring World Tour teams and supplying the biggest bike brands. FSA bearings are manufactured to ultra-precise tolerances, tested in the laboratory and in the field by professionals. Choosing an original FSA bearing guarantees perfect compatibility, reliability and expected performance, with an excellent quality-price ratio for such a strategic wear part as the headset.