Press-fit bottom bracket shells eliminate frame threading, which simplifies manufacturing but creates a headache when you need to service or replace bearings. SRAM's GXP PressFit BB86 Bottom Bracket addresses BB86 shells—the 86.5mm wide, 41mm diameter standard found on many carbon road frames—with a straightforward angular contact bearing design that interfaces with GXP cranks.

The GXP spindle standard uses a stepped design: 24mm on the drive side tapering to 22mm on the non-drive side. This asymmetry means GXP cranks only work with GXP-specific bottom brackets, and this press-fit unit delivers that compatibility for frames built around the BB86 shell. Angular contact bearings handle the combined radial and axial loads that pedaling generates, with the contact angle optimized for the force vectors you actually produce during a pedal stroke.

Installation requires a press-fit tool to seat the cups evenly into the frame shell. The cups sit directly against the frame's carbon or aluminum surfaces, so proper alignment matters—a crooked installation creates uneven bearing loads and accelerated wear. Most shops have the correct tooling, and if you're doing it yourself, a quality press-fit installation tool pays for itself over a few bottom bracket changes.... Read More