6808 LLB BO 45 - 1-1/2 Black Oxide treated Headset Bearing (40mm x 52mm x 7mm: 45deg ID only) Trek BB90 bottom brackets require

Trek BB90 bottom brackets require the bearing to be directly pressed into the BB shell that is often made from a material that is softer than steel

and XD15 Ceramic-Hybrid at the top of the line

45 Angular Contact

440C stainless steel balls and races to provide long life and superior corrosion resistance in applications and environments that may be less than ideal

Guaranteed to last forever against corrosion

6808 LLB BO 45 - 1-1/2 Black Oxide treated Headset Bearing (40mm x 52mm x 7mm: 45deg ID only) Trek BB90 bottom brackets require6808 LLB BO 45 1 1 2 Black Oxide treated Headset Bearing (40mm x 12mm x 7mm: 45deg ID only) Radial design headset bearing featuring anti corrosion Black Oxide Magnetite treated 52100 High Carbon Chromium alloy races paired with grade 10 Balls. Black Oxide treatment provides an extra level of corrosion resistance and extended worry free performance This size bearing is also known in the bike Industry by part number: HSS 6011 The Enduro line of angular