Enduro Sealed Angular Contact Headset Bearing 6808 SS, 290413 - 1 1/2" - 40 x 51 x 6.5mm (36 x 436 deg)

ACB 6808 SS, 290413 - 1 1/2" 440C Stainless Steel Angular Contact Headset Bearing - 40 x 51 x 6.5mm (36 x 36 deg)

Angular contact headset bearings, boasting 440C stainless steel balls and races for superior defence against corrosion, stand out in their performance. It's important to note that these bearings differ slightly in dimensions from our other ACB 6808 bearings: they possess a slightly smaller outer diameter and feature 36-degree chamfers internally and externally. Originally specified by Trek for their Madone and Domane bikes, these bearings offer unique specifications.

Enduro exclusively employs 440C stainless steel balls and races, prioritizing longevity and exceptional resistance against corrosion in environments that might not be ideal. Among the standard 440-series stainless alloys with a high carbon content, 440C stands out for its exceptional strength, hardness, and wear resistance. Achieving its superior mechanical properties demands multiple rounds of heat treatment and cryogenic treatment, making it the most costly within the 440 series. Although stainless steel carries 20% less load capacity and is slightly softer compared to our standard 52100 chromium steel utilized in most bearings, it serves as an excellent alternative for wet conditions, frequent bike washes, or areas susceptible to sweat. Enduro Bearings further enhances these bearings with LLB-type seals and CRC Marine grease, ensuring additional waterproofing against various elements. Recognized in many renowned headset brands, Enduro 440C stainless headset bearings are the same bearings covered by a 110-year warranty.

The Enduro series of angular-contact headset bearings begins with Black Oxide treated Chromium Steel races, progressing to full 440C stainless steel, and culminates in the top-tier, lifetime-guaranteed XD-15 aerospace-stainless (races and balls). These bearings are meticulously engineered with maximized ball size, incorporate dual-lip seals within micro-grooves (labyrinth), and are filled to 90% capacity with high-pressure waterproof grease, ensuring ultimate protection against sweat and environmental factors. Engineered for even ball engagement, Enduro Angular Contact (A/C) bearings distribute force across a larger surface area, minimizing wear and extending their lifespan significantly.