Introduction by Francis Cebedo
Ahh the carbon 29er hardtail… it is the weapon of choice by every XC racer and Strava KOM hopeful these days. But which one does one choose? What qualities should the rider look for?
Niner fired the opening shot in this arena when they launched the Air 9 Carbon a few years ago. Here was a bike with stunning good looks featuring a massive downtube and tubes that were sculpted to look and perform good. It was extremely responsive to power input and it was laterally stiff for even the heaviest riders. It also had a flexible bottom bracket that could take a normal geared configuration or an EBB for singlespeed use. This bike was hot as it featured the best paint jobs and internal cable routing to deliver a clean looking bike.
But upstarts like the Santa Cruz Highball and Scott Scale came to play and came in with smaller tubes that were more compliant with frame weights around 2.5 lbs, which were about .5 lbs lighter than the Niner Air 9 Carbon. Singlespeed configuration was not available but most buyers didn’t seem to mind.
So Niner has fought back with the Air 9 RDO Carbon. This bike has smaller tubes for lighter weight and a more compliant ride in the rear. It has a normal bottom bracket for simplicity and lighter weight. And it has a disc brake that is mounted inside the rear triangle as it’s bolted on the chainstay rather than the seatstay. This not only improves aesthetics but it also allows a more compliant ride as the seatstays can be tuned for ride quality without having to support a disc brake mount.
The RDO frame is indeed .5 lbs lighter than the Air 9 RDO Carbon but it still feels very stiff and responsive to pedal input. The frame is laterally stiff and it still carves the trail well. The Air 9 Carbon however is the stiffness king of the family and a heavier, more aggressive rider may want that frame for better acceleration and better lateral stiffness. The RDO, with it’s smaller tubes is not quite at the same lateral stiffness as the Air 9 Carbon. The ride has improved as the rear seems more forgiving on the rough stuff. The bottom bracket is much simpler and more traditional than the Air 9 Carbon and it is much less prone to creaking. Brake adjustment is a little harder to get to but it performs well and looks very clean once set up.
RDO with Enve-Kappius wheels built by Wheelbuilder.com
How does it compare to the Santa Cruz Highball? I think they’re an equal match as they’re both 2.5 lbs and they both deliver a responsive yet forgiving ride. They have very similar ride qualities with blistering acceleration complemented by a fairly compliant ride. In terms of lateral stiffness, the Highball has a slight edge over the RDO. The seat tube on the Niner is shorter by two inches so a lot more seatpost is showing. The gives the bike a lower feel as the top tube is closer to the ground. Consequently, standover height is lower on the Niner giving it the rider more top tube clearance on those unplanned dismounts. Finally, the seat angle on the Niner is steeper on the Niner giving it a more aggresive, ‘hammer over the pedals’ position, ideal for cross country racing.
Sizing is different though as I ride a medium Santa Cruz Highball and that is about equal to a small Niner, particularly in top tube length. The Niner does look better though and it has a better component spec with 2×10 setups and Schwalbe tires. Santa Cruz still insists on 3×10 setups, house wheels and Maxxis Crossmark tires.
Comparison Chart of the Small Niner RDO and a Medium Santa Cruz Highball both with 100 mm front fork:
|Bike||Seat Tube (c-t)||Effective Top Tube||BB Height||Head Tube Angle||Seat Tube Angle||Seat Tube Angle||Stand Over||Chainstay|
Both bikes weigh in at 2.5 lbs. The Niner Air 9 RDO frame is $2099 and the Santa Cruz Highball is $1999
Review by Aaron Faupell
In Niner lingo the RDO stands for Race Day Optimized. As the name attests, the Air 9 RDO is a bike built for a singular purpose and it suits that purpose very well. But as you might expect when a bike is built to a narrow focus it can often fall short in other areas outside of that. As a race bike the RDO is very good at helping you win races, setting PRs and and making you feel fast. The out of the saddle climbing is amazing with stiff bottom bracket supplying a distinct feeling of surging forward with every pedal stroke. However when you reach the top of the hill and point the bike downwards the race oriented setup catches up with you. The weight distribution is somewhat forward and the handling is fairly quick. It is definitely not slow enough to make up for the time gained on climbs but one has to be aware when bombing down technical descents.