First Impression: Niner Air 9 RDO

By Josh Patterson

Niner expanded their RDO (short for Race Day Optimized) line this spring with the introduction of the Air 9 RDO. Niner used the Air 9 Carbon (read our full review here) as the foundation for building this carbon hardtail. The company’s goal was the shed weight while adding a bit of compliance to the new frame (two objectives that generally go well together).

Where the Air 9 Carbon uses Niner’s CYA bottom bracket system—an oversized bottom bracket shell with a 55mm inner diameter that is compatible with press-fit, threaded, and Niner’s eccentric bottom bracket—the Air 9 RDO forgoes this expansive range of compatibility in favor of a lighter PressFit 30 bottom bracket.

To improve compliance, the company used smaller diameter top and downtubes. The rear brake mount was moved from the seatstay to the chainstay, allowing for a lighter, more forgiving carbon layup to be used on the seatstays.

One subtle revision that is sure to please mechanics is full-length cable routing through the headtube. This should simplify Niner’s internal routing; I would not be surprised if Niner’s other carbon models follow suit.

Sea Otter’s mountain bike fondo was a good proving ground for this race-ready hardtail. Being a Fondo, we were not technically “racing," although that didn’t stop me, and a handful of like-minded participants, from turning it into a competition—I have my Strava reputation to think of…

After twenty miles of fire road and singletrack, I feel Niner has done a good job of balancing comfort and performance. The trails around Monterey are mostly hardpack, but are full of stutter and braking bumps that quickly take their toll. The RDO’s rear end did a commendable job of muting high-speed trail chatter, and I never encountered a situation in which I was left wanting for stiffness. I could see this bike being an excellent choice for endurance racers who prefer the lightweight and simplicity of a 29er hardtail to a full suspension.