Niner Jet 9 RDO 27.5+ 3-Star XT Complete Mountain Bike - 2017

Brave departure.

The latest addition to Niner's trail bike team is—wait for it—27.5+ compatible. Given that Niner is literally named after wagon wheels, the Jet 9 RDO 27.5+ 3-Star XT Complete Mountain Bike's brave departure may initially be unsettling to the brand faithful; however, we're confident that the added capabilities of 27.5+ will more than win over any 29er heroes. The new wheel size isn't the only big change, though. The 2017 Jet 9 represents a radical departure from the previous Jet geometry. It's now longer across the top, slacker up front, steeper out back, and has 20 more millimeters of Continuously Varying Arc (CVA) travel. When combined with the plush traction of the 27.5+ platform, these changes equate to better climbing and—more importantly—a more aggressive approach to trail furniture typically reserved for all-mountain bikes.

As with most bikes in the current trail generation, the key element underwriting the new Jet 9's versatile geometry is its Boost rear axle. Bumping the spacing up to 148mm lets Niner chop 21mm off of chainstays by slamming the rear wheel up into the seat tube. The extra clearance also allows for 3in tires on 27.5 rims, which equates to more traction across rain-slicked roots and a bit more cushion when the terrain gets chunky. The steeper seat tube keeps you centered over the pedals for more efficient climbing while the included dropper post allows you to clear out some cockpit space so you can throw the bike around on descents.

The 27.5+ Jet 9 also includes a deeper fork, running 140mm instead of the 29er model's 130. This keeps the geometry relatively in line across wheel sizes, though the 27.5+ version does shed an extra half degree in the head tube. This positions the 27.5+ Jet 9 that much closer to enduro nastiness. It also pairs nicely with the new iteration's longer reach and shorter stem, making for a bike that can ride roughshod across all manner of trail furniture without sacrificing responsive steering. Slack head tubes are fun, but we're occasionally frustrated by their muddy responsiveness. The Jet 9 lives up to Niner's reputation of nimble, big-wheeled machines by applying that ethos to the mid-wheel range and ensuring that enduro aggression doesn't come at the cost of control.

Despite the above changes, Niner's Race Day Optimized (RDO) construction process remains relatively unchanged. This is a good thing, as Niner's compaction method presses out any excess resin and compacts the carbon down to a uniform wall thickness. This gives Niner precise control over where material is and where it isn't, letting the engineers actually engineer the frame by reducing weight where it's not needed while ensuring stiffness and durability at key areas of power transfer and abuse.

The CVA suspension model is also virtually unchanged. CVA is designed specifically around 29in wheels to keep the big-rim platform balanced between taut and supple. Since there's little difference in the dimensions between 29 and 27.5+ platforms, it translates well to donut-tire models. CVA's low compression ratio means there's less need for suspension preload, so the mechanism can float more freely and react more readily to the terrain without being loose or sloppy. The lower linkage's placement beneath the bottom bracket isolates pedal input from suspension action to prevent the system from bobbing or back-kicking, resulting in a smooth but efficient bike that's responsive to both your power and the trail's trickery.

The frame's finishing details are everything you'd expect from the obsessive developers at Niner, and our favorite new addition is—far and away—the inclusion of a BSA threaded bottom bracket. PressFit shells may be lighter and more convenient, but the exact tolerances of a CNC-machined thread are virtually unsurpassable by today's composite technology. The threading means bearing cups install perfectly, reducing wear over time and eliminating the creaks, groans, and pops that so often accompany PressFit models. Vulnerable bits are girded with titanium protection plates. The frame also includes integrated batter storage in case you get the urge for electro shifting and the revised axle spacing and geometry dimensions accommodate 29er tires up to 2.4in and 27.5 tires up to 3in.

  • Niner's brave departure into the realm of 27.5+ trail bikes
  • 20mm more CVA suspension compared to previous Jet 9
  • Updated geometry climbs faster and descends harder
  • Plus-sized tires for more traction and lower PSI
  • RDO carbon construction drops grams to gain speed
  • Compatible with electronic drivetrain routing and battery storage
  • Shimano's workhorse drivetrain fears no trail
  • Plush tires add cushion for enduro shredfests and bikepacking epics
  • Reviews
  • Q & A

Absolute Beast

  • Familiarity: I've put it through the wringer

Niner has updated the JET 9 once again, going longer and slacker to make this trail bike even more capable. I was able to demo both the Jet and Rip 9 down in Moab. I was absolutely blown away on how fun the Jet 9 was. We rode mag 7 and this bike ate the entire trail up. The plus tires allowed for tons of grip on the loose desert sand. The bike was super punchy on those short slick rock ascents. I was riding a medium and was really happy with how agile it was. The geometry and travel made for a more than capable descender. The CVA suspension gives the feel of a longer travel bike and is super stable at speed. The bottom line is Niner has created a bike that balances descending performance with climbing efficiency.

Feel free to hit me up with any questions regarding bikes:

Size Frame: What size frame should you go with?

Travel: Finding the right amount of travel that fits your riding style.

Full Package: Can provide a quote for both a custom or complete box build that fits your budget.

Comparison: How does this bike ride compared to others in the same class? What are the pros and cons of going with another option?

Patrick Law

It's the Niner that's not a Niner!

  • Familiarity: I've used it several times

I rode both the 29 and 27.5″ plus versions and can tell you that they both had different characteristics…didn’t have much issues with medal bashing but definitely could tell a difference with the smaller(ish) and fatter tires. I did a quick video review…

Dirt Eating Grin

  • Familiarity: I've used it once or twice and have initial impressions

I demoed this bike, as well as their Jet RDO. My smile says it all, eh? This model is a super fun bike! Really sweet on the downhill. I definitely felt in control of the bike, when I wanted to slow down. No fishing tailing here.

I didn't struggle going up either. I thought I would, but it was great on the uphill. I would enter an up hill race or anything, but it really moved. Also, the comfort and confidence you have going over rocks and trees keeps you from hesitating at all.

I would not hesitate to make this my next bike. I'm 5'8 with a 32" bike-inseam and the medium frame is perfect.

Dirt Eating Grin

The New School Is In Session

  • Familiarity: I've used it once or twice and have initial impressions

The totally revamped Niner Jet9 is one sweet little sleigh.
*Shorter Stays
*Longer TT
*27.5+ <>29 compatible
*Slacker HT

All the boxes are checked. I had the chance to get some ride time on the 27.5+ bike. The bike felt quick. Straight line, Up, Down, everywhere. The plus tires were quite fun- SO much grip! The ability to go from 27+ to 29 is huge. The 67 HT felt dialed and in control ripping down. Climbing up switchbacks I really noticed the shorter chainstays as this thing felt like it spun on a dime. I would definitely keep this bike in consideration if you were looking for a short travel trail bike. I'd love to share my experience, or help answer any questions.

Edit*- I have also had the chance to take out the 29er version. This is more my personal style- fast moving, quick on the swithcbacks- everything I want in a trail bike. Whatever flavor you choose- you're going to really enjoy this bike!

If you have any questions or just want to chat bikes you can reach me directly at 801-204-4588
Scott Gartman: Expert Gearhead-Bike

The New School Is In Session

All boxes checked, nothing but good things to say. Why only 4 out of 5 stars?