HSC BB90 / 95 Ceramic Bottom Bracket

These hybrid ceramic bearing kits from HSC are designed to fit Trek's BB90 road and BB95 mountain direct-fit bottom bracket shells, and are available for either Shimano Hollowtech II or SRAM GXP cranksets.

HSC's ceramic hybrids use grade 3 silicon nitride (Si3N4) balls matched with hardened steel races and low-friction seals and retainers. The grade of the ball bearings refers to their sphericity the lower the number, the closer the ball is to being perfectly spherical, in thousandths of an inch. As a reference, the highest quality stainless steel ball used in bicycle applications is rated at grade 25.

ORDERING

These adapters are designed to fit frames with 90.5 mm or 95.5 mm wide bottom bracket shells. The option you require will depend on the crankset being used:

Shimano HTII - Designed to fit 24 mm spindle cranks

SRAM GXP - Designed to fit stepped 24 / 22 mm spindle cranks.

INSTALLATION / ASSEMBLY

To avoid frame damage, we recommend that these BB90 / 95 bottom bracket adapters be professionally installed using a proper bearing press.

Please feel free to contact us directly for technical questions.