ENDURO STAINLESS STEEL ANGULAR CONTACT HEADSET BEARING 45 X 45 40.5 X 49.5 X 6.5

The Enduro Stainless Steel Angular Contact Bearing is a high-performance, rust-resistant steering solution designed for specific oversized headset standards. While standard bearings often fall victim to the "creeping death" of rust—caused by road spray, humidity, and falling sweat—this bearing is forged from 440C Stainless Steel. This premium material ensures that the races and balls remain impervious to oxidation, maintaining a silky-smooth, predictable steering feel even in the harshest riding conditions.

This is an Angular Contact (ACB) bearing with a 45° x 45° geometry, meticulously engineered to manage the simultaneous vertical and lateral loads unique to bicycle head tubes. Measuring 40.5mm x 49.5mm x 6.5mm, this specific size is often utilized in high-end road and gravel headsets that require a slightly larger internal diameter than the standard 1.5" or 1 1/4" bearings. With its mirror-polished tracks and waterproof grease, it is the ultimate "fit-and-forget" upgrade for riders who refuse to compromise on durability.

Key Performance Features

• 440C Stainless Steel Construction: Forged and precision-machined to provide total immunity to rust and corrosion, making it the premier choice for bikes exposed to salt air, rain, or heavy indoor trainer use.

• 45° x 45° Contact Angles: Features matching internal and external 45-degree chamfers to ensure perfect centering within the head tube and optimal load distribution across the steering axis.

• Mirror-Polished Internal Races: The stainless steel ball tracks are polished to a high-gloss finish, reducing internal friction for a light, responsive, and noise-free steering experience.

• Dual-Lip Labyrinth Seals: Equipped with high-contact seals that create a redundant barrier, locking out road grit and moisture while retaining the essential factory grease.

• High-Fill Marine Grease: Factory-packed with a specialized waterproof lubricant that resists wash-out and maintains its viscosity through thousands of steering cycles.

• Precision "In-Between" Sizing: Specifically engineered for 40.5mm ID applications, ensuring a precise, play-free fit for specialized headset standards.

Technical Specifications

✅ Why This IS For You

• The Indoor "Pain Cave" Specialist: If you spend your winters on a stationary trainer, the stainless steel construction is a mechanical necessity to prevent acidic sweat from seizing your headset.

• Coastal & Wet-Weather Riders: Ideal for those who live near the ocean or ride year-round in climates where salt and moisture normally destroy standard steel bearings within a single season.

• Integrated Cockpit Owners: Perfect for modern bikes with hidden cabling where the complexity of replacement makes the extreme longevity of a stainless bearing a smart investment.

❌ Why This May NOT be for you

• Standard 1.5" or 1 1/8" Steerers: This bearing features a specific 40.5mm ID. It will not fit standard 1.5" (40mm) or 1 1/4" (34.1mm) headsets. Always verify your existing bearing dimensions before ordering.

• 36-Degree Headset Frames: If your frame or compression ring is cut at a 36-degree angle, this 45-degree bearing will not seat correctly and will cause headset play.

BFC Pro Tip

The 40.5mm internal diameter is a specific measurement—even 0.5mm of difference can prevent a bearing from seating correctly or cause it to wobble. Before installation, use a clean rag to remove all old grease and grit from the frame seats. Even though this bearing is stainless steel, we recommend applying a layer of waterproof assembly grease to the outer chamfers. This provides an additional "hydrostatic seal" to keep water away from the frame and prevents the annoying "creaking" often associated with carbon fiber head tubes!