The Enduro BB90 Trek Seal 24mm Spindle (Model: END.281820) is a crucial, precision-moulded component designed to address the unique engineering challenges of Trek’s proprietary BB90 and BB95 bottom bracket standards. On these specific carbon frame structures, the bottom bracket bearings are pressed directly into the raw carbon frame shell rather than utilizing traditional alloy or composite cups. This weight-saving layout creates an exceptionally crisp, integrated look, but it leaves the internal bearing races highly vulnerable to water ingress, frame-washing spray, and abrasive trail grit. Without a specialized barrier, contaminants can quickly migrate past your external dust shields, causing structural corrosion, premature bearing failure, and irritating drivetrain creaks.

Engineered from a high-durability, light-contact silicone compound, this auxiliary seal serves as the ultimate defensive barrier for your drivetrain. It features a precision-cut 22mm inner diameter that stretches tightly to fit smoothly over standard 24mm spindles—such as Shimano Hollowtech II, RaceFace, and FSA—creating a reliable, frictionless jacket that rotates seamlessly with your crankset. By completely sealing the vulnerable interface where the spindle enters the frame socket, it prevents micro-grit from wearing down the delicate carbon bearing seats. Whether you are replacing a lost factory seal or refreshing your high-end road or mountain bike, this Enduro upgrade keeps your drivetrain rolling smoothly and silently through the harshest conditions.

Key Features

• Trek Proprietary Integration: Engineered explicitly to fit the unique molded frame sockets of Trek BB90 (road) and BB95 (MTB) bottom bracket platforms.

• Premium Silicone Material: Moulded from a resilient, high-grade silicone compound that maintains its shape and flexibility across intense heat and cold cycles.

• Frictionless Light-Contact Lip: Features an ultra-slim, low-drag profile that locks out environmental debris without increasing mechanical resistance or drag.

• 24mm Spindle Optimisation: Sized at 22 x 40mm to snap tightly onto 24mm spindle cranksets, creating a reliable, moving labyrinth barrier against moisture.

• Protects Sensitive Carbon Shells: Seals off the bearing-to-frame interface, stopping gritty paste from acting like sandpaper inside your raw carbon bottom bracket shell.

Specifications

• Brand: Enduro Bearings

• Part Code: END.281820

• Component Type: Auxiliary External Bottom Bracket Seal

• Material: Light-contact Silicone Elastomer

• Dimensions: 22mm (Inner Diameter) x 40mm (Outer Diameter)

• Frame Standard Compatibility: Trek BB90 and Trek BB95

• Crankset Compatibility: 24mm Spindle Systems (Shimano, FSA, RaceFace)

• Quantity: Sold individually (1 piece)

✅ Why This IS For You