Enduro Bearings ACB 6808 Stainless Steel 1.5 (36×36º) Headset Bear

51mm OD x 40mm ID x 6.5mm Width – 36 x 36 degree – Stainless balls with stainless races

This bearing is for the Trek Madone 6-Series frames with 1-1/2″ lower headset. Part replacement for Trek Part #290413 
and Cane Creek Part #HD1449S

Features

LLB Seals – Enduro Bearings use LLB type seals and CRC Marine Grease in their 440C Stainless Steel bearings, their most popular seal type, this is a Nitrile material rubber with a steel insert. Rather than the standard 2RS type seal, Enduro go a step further by machining a groove into the inner race where the seal can rotate with better efficiency and less rolling resistance. Rather than one thick seal lip rubbing on a blunt surface, LLB type utilizes two razor thin sealing lips riding in the groove with light contact. The outside lip keeps the water and contaminates out, while the inner seal retains the grease for smooth function and long intervals between servicing.

440c Stainless Steel – Enduro only uses 440C stainless steel balls and races to provide long life and superior corrosion resistance in applications and environments that may be less than ideal. 440C has the highest strength, hardness, and wear resistance of all the standard 440-series stainless alloys with high carbon content. As expected it is also the most expensive of the 440 series alloys and requires multiple rounds of treatment processes to achieve its superior mechanical properties. Superior to the more commonly used 440A or 440B that other bearing manufacturers use interested in saving money, 440C stainless steel alloy has a higher Carbon content giving it maximum hardness and corrosion resistance after heat treatment and cryogenic treatment.

When the rain won’t go away, and your bicycle seems more often to be used as a boat rather than a bicycle, you may want to consider 440C stainless steel bearings. While not quite as hard as chromium bearing steel, 440C stainless steel is a good alternative in constant wet conditions, or where sweat and sticky drinks become a problem with components such as headset bearings and bottom brackets. In fact, Enduro Stainless Steel bearings have become so successful we are now one of the largest suppliers to premium component makers interested in having no warranty problems and the best performance for their customers. 

Angular Contact – In standard radial bearings, only 3 or 4 balls make contact during the load, at any given time. In Angular Contact (A/C) bearings, ALL balls are engaged and spread the force over a larger surface area, to decrease friction and minimize wear.