The Niner BioCentric II makes adjustments easy across a wide range of gears and eliminates the need for adjustable dropouts, giving the cleanest possible solution for singlespeed use. No bolt on hubs, no chain tensioners cluttering your ride, no brake adjustments with gear changes.
The BioCentric 30 will have a similar design and function as its BioCentric II counterpart, but compact for use in most PF30 shells. The sealed bottom bracket will be integrated into the cups of the BioCentric 30 and will be capable of handling most 24mm spindle cranks. The BioCentric 30 is compatible with the Air 9 RDO (Boost spaced frames only) Air 9 Alloy, RLT 9 Steel and RLT 9 only.
This part is not returnable.
The BioCentric II offsets the bottom bracket spindle 8.5mm from center, offering greater range of adjustment compared to a more traditional EBB setup. More offset is a boon when changing gears without having to change chain length and it allows riders to make more noticeable changes to frame geometry via BB position.
Traditional EBB units are held in place with set screws that can become difficult to finely adjust over time, or expansion wedges that can deform the bottom bracket shell of the frame. Split BB shells that clamp an EBB can stretch or ovalize. The BioCentric II avoids these troubles by using two bolts to apply a clamping force on the outside edges of the BB shell, eliminating the possibility of ovalizing or indexing the shell itself. Secure, quiet, easy to install and adjust, the BioCentric II will change your ideas about singlespeed drivetrain setup and maintenance.