Whether you're a hardened endurance racer, or you're just looking for a way to sharpen up your skills, a rigid, singlespeed 29er will inject a whole new sense of fun into your favorite trails. But just because these machines are simple doesn't mean they're not advanced, as the Niner ONE 9 RDO 2 Star SS Complete Mountain Bike indisputably proves. The featherweight carbon fiber frame is paired with Niner's own carbon fiber, thru axle equipped fork, which many consider the benchmark rigid mountain option. And with a lightweight, sensible build kit, it just begs to be raced. That might mean strapping on a number plate, or just dropping your buddies on the next post work ride that choice is up to you. The ONE 9 RDO benefits from all of the weight saving measures that have made the AIR 9 RDO the notorious race rocket that it is. At the core of every Niner frame is extensive computer based finite element analysis, and here it's used to develop a high modulus carbon fiber structure with optimized weaves, layups, and tube shapes ultimately producing the lightest Niner to date. The RDO's fluid form is no accident, and it's designed to minimize chatter and guide impact forces to the strongest parts of the frame. Chain torque goes directly to the rear wheel via the oversized CYA bottom bracket shell and shapely chainstays, yet trail vibrations are quelled by the swooping seatstays. Niner ties the bottom bracket to the precision enhancing tapered head tube via a large down tube to ensure the frame tracks true and responds to every input. What separates the ONE 9 RDO from its AIR 9 ancestor is the use of Niner's CYA bottom bracket interface. It's oversized to make room for the included BioCentric eccentric bottom bracket. Unlike other EBBs, BioCentric has a track record of being easy to use and remaining creak free, but the real benefit is that it allows for the use of a fixed rear dropout. On top of being the lightest option, it avoids the slippage that can occur with ...