Since their inception, we've had a love hate relationship with eccentric bottom brackets. They offer some serious advantages over sliding dropouts, but have their own set of design flaws to overcome. Traditional eccentric bottom brackets use set screws or an expanding wedge to hold the eccentric in place. The set screws can strip out and mar the eccentric, making adjustments difficult as it ages. The expanding wedge eventually ovalizes the bottom bracket shell, again, making adjustments difficult. Niner has overcome this problem with the EBB Bio Centric V2. An essential design element of the Bio Centric system is that the cups lock to the bottom bracket shell's flange. Once the EBB is in position, one bolt tightens the two eccentric pieces against the flanges, providing 360 degrees of purchase while eliminating any chance for creak causing dirt or debris to contaminate the interface. Also, the shell won't ovalize or suffer from the over tightening issues of traditional EBB designs. This simple solution makes your Niner the true Zen machine SS bikes should be. The wheel can be removed without readjusting caliper position or chain tension, and you're guaranteed perfect dropout to frame alignment, unlike individually adjustable sliding drops. This means your brakes are always perfectly aligned and your rear wheel will never slide out of place and rub on your stays. The Bio Centric V2 offsets the bottom bracket spindle 8. 5mm from center, which offers a greater range of adjustment than most eccentric bottom bracket setups. This allows you to use a greater range of gears and makes changes to your frame geometry via the bottom bracket more noticeable. The Niner EBB Bio Centric V2 comes in Black and is compatible with all Niner EBB frames.