ENDURO STAINLESS STEEL ANGULAR CONTACT HEADSET BEARING 45 X 45 40 X 52 X 7

The Enduro Stainless Steel Angular Contact Bearing is the definitive performance upgrade for the most vulnerable part of your bicycle: the lower headset. Positioned directly in the line of fire for road spray, mud, and grit, the lower bearing usually fails first. By utilizing 440C Stainless Steel for both the races and the balls, Enduro has created a bearing that is virtually impervious to the rust and pitting that plagues standard steel components.

Measuring 40mm x 52mm x 7mm, this is the industry-standard size for the 1.5" lower bearing found on almost all modern tapered road, gravel, and mountain bikes. With its 45° x 45° angular contact geometry, it is designed to seat perfectly into the frame and against the crown race, providing a rock-solid, creak-free steering interface. Whether you're power-washing your mountain bike or sweating through a three-hour indoor trainer session, this stainless steel unit ensures your steering remains buttery smooth and responsive.

Key Performance Features

• 440C Stainless Steel Construction: Forged and precision-machined to provide total immunity to corrosion, ensuring the bearing won't "index" or seize even in salt-heavy or high-moisture environments.

• 45° x 45° Angular Contact: Specifically engineered to handle the massive vertical and lateral loads exerted on the lower head tube, ensuring even wear and zero steering play.

• Mirror-Polished Internal Races: The stainless steel tracks are polished to a high-gloss finish, reducing internal friction for a light, "new-bike" steering feel.

• Dual-Lip Labyrinth Seals: Features heavy-duty, high-contact seals that act as a redundant barrier, locking out road grime while retaining the essential factory lubricant.

• High-Fill Marine Grease: Factory-packed with specialized waterproof grease that maintains its viscosity and stays in place through the most demanding riding conditions.

• Oversized Durability: Specifically built to handle the high leverage forces of long-travel forks and aggressive gravel geometries.

Technical Specifications

✅ Why This IS For You

• The "Ride in All Weather" Cyclist: If you don't let rain or winter grit stop you, the stainless steel construction is the only way to avoid annual headset replacements.

• Indoor Trainer Specialists: The lower headset is a "catch-all" for falling sweat; this bearing is immune to the acidic corrosion that typically destroys standard bearings in the "pain cave."

• Integrated Cable Owners: For bikes where cables run through the headset, the extreme longevity of this bearing is a smart investment to avoid the massive labor costs of a re-cable.

❌ Why This May NOT be for you

• 36-Degree Headset Frames: Always check your old bearing or frame specs. If your frame requires a 36° angle, this 45° bearing will not seat correctly and will damage your head tube.

• Ultra-Lightweight Racing: While significantly more durable, stainless steel is slightly denser than ceramic. For a "weight-no-object" hill-climb build, an Enduro Ceramic option might be preferred.

BFC Pro Tip

The 40mm ID x 52mm OD is the most common lower bearing in the world today, but the 45° x 45° chamfer is what ensures a quiet ride. When installing, apply a liberal coating of waterproof assembly grease to the chamfered edges and the internal head tube seat. This creates a "gasket" that prevents water from pooling around the bearing and stops the "creaking" often associated with carbon frames. Since this bearing is stainless steel, it is incredibly hard—ensure your top cap is adjusted just enough to remove play, and you'll likely never have to look at this bearing again!