JET 9 2-Star Complete Mountain Bike
Transitioning between cross country and more aggressive trail riding can be tricky on your race-geometry rocket, and many trail bikes are a bit too-slacked out for the agility you want when spinning around your local XC trail network. Enter the JET 9 2-Star Complete Mountain Bike. The bike was recently redesigned with slacker angles than before, so you can send it down gnarlier trails and gobble up rocks that would have sent you flying in past years. This trail-ready bike combines some of the agility of its XC jet-pack roots with the growing demand riders have for longer and lower geometry to dominate the whole mountain.
When things started out for Niner Bikes, it was apparent from the name alone that their founders had a strong belief that 29-inch wheels were the superior mode of transportation on a mountain bike, and their designers more or less defined the category of proper 29er geometry. This particular 2-Star NX Eagle build holds true to those roots, but allows for the flexibility to swap to 27.5+ wheels and tires for impressive rock-crawling traction. It comes stock with Niner's own 29-inch alloy hoops, so you'll have the quick rolling readiness of a 29er, but with the coming of Boost 148mm rear hub spacing, the hub is widened and creates the room you need to throw on a smaller rim with a beefier tire, should you be feeling experimental, or just want to find out what this whole high-volume tire craze is about.
The latest update to the Niner Jet 9 frame moved the speedy XC race geometry, and gave it a bit of a makeover to make it a better all-around trail bike for sending it on the whole mountain. An additional 20mm of travel was added to the Continuously Varying Arc (CVA) rear suspension, which brings the total to 120mm. The headtube moved a bit slacker, the seat tube steeper, and the reach stretched out a bit longer, making the Jet 9 a much more trail-hungry beast than in previous years. For those worried about the loss of an XC bike, the RKT has stepped in to take the race-rocket place of the Jet as the new go-to for an XC race machine.
Climbing is efficient with Niner's Constant Varying Arc suspension, without compromising that smooth and bottomless feel we covet. CVA, along with FOX's Float DPS Performance EVOL rear shock, manages to throw 4.7-inches of boulder-hungry travel into the rear end for gobbling up rock gardens and rooty tree lines. CVA works by pulling the bottom link down as you pedal, avoiding pedal bob, while the top linkage is free to move and respond to rocks and bumps on the way up.
Complimenting CVA and the Fox Float DPS rear shock is a Fox Float 34 Rhythm fork, equipped with 130mm of travel for soaking up rocks and blows on the trail. The 34mm stanchions offer supple support for tracking your line down the mountain with confidence. This particular build is designed around the 29er wheel, making a 130mm fork appropriate for its geometry, but Niner recommends swapping to a 140mm fork for 27.5+ wheels, along with a 15mm lower headset cup to compensate for the subtle changes in geometry and the lower bottom bracket height that comes with running a slightly smaller wheel. The 2-star NX build sees SRAM's NX Eagle drivetrain, which offers a massive 11-50 tooth 12-speed cassette. With the pluses of Eagle, you'll find a gear for any climb or descent, with a huge bailout cog for those super steep and punchy moments when a 42 or 46-tooth won't do. SRAM's NX Eagle has the technology of their XX1 and X01, but with a bit more weight and huge price savings, making Eagle attainable to those looking to keep a tighter budget.
The frame is constructed from durable aluminum alloy, and has clearance for up to 29 x 2.6in or 27.5 x 3.0in tires according to Niner, though this can vary as some brands may not fit. All frame sizes fit one water bottle inside the front triangle, and feature titanium frame guards to protect it in critical areas. The threaded bottom bracket allows easy maintenance and virtually eliminates the creaks that plague press fit systems, while external cable routing further simplifies maintenance (it does have internal dropper post routing). The frame is designed to capture long, low geometry that's popular in today's trail bikes. The longer reach allows you to run a shorter stem, which enables quick handling, while keeping your weight back, so long descents are a breeze. Shorter chainstays come in at just 434mm, tucking the rear wheel up underneath you to find better climbing traction, as well as agility for flicking the bike through tight switchbacks and trees. For the perfect balance between slack and steep, the head angle falls at 67.5-degrees, perfect for precise steering with both slow-speed encounters and high-speed stability.
- Niner's do-it-all trail bike excels on any terrain
- 4.7in of plush yet efficient CVA suspension gobbles up bumps
- Modern geometry powers up climbs and bombs down descents
- Aluminum frame is resilient and has threaded bottom bracket
- SRAM NX Eagle adds the huge gear range without the price of XX1
- FOX suspension smooths out terrain and is easy to adjust
- Boost spacing improves lateral stiffness and tire clearance
- Pulls double duty with compatibility for 27.5+ and 29in wheels