Keep It Steel, Stud. The 4130 Cro-Mo tube set of the ROS 9 is the trusted standard for durability and ride quality. Following the lines and design language of the SIR 9, these tubes have been beefed up to handle the abuse the ROS 9 is designed to shrug off. The super-short chainstays provide a lofty front end feel while the slack HT angle keeps the front end composed at Mach Loony speeds. A neutral BB height can be made low or high to slay YOUR trails by positioning the BioCentric 2 where it will do the most good.
CONSTRUCTION DETAILS ABOUND
We borrowed the unique dropout design we developed for the SIR 9 to allow 142x12 Maxle use and house the stout alloy derailleur hanger. The dropout designs allow the chain stays and seat stays to be welded at any angle and provide far more surface area for a full weld around the tube’s end. The front derailleur hanger is removable with an alloy cover. Internal dropper post routing is optional, another alloy cover closes the port if you choose not to use it. Externally routed dropper posts utilize mounts under the top tube. Tabs under the bottom bracket shell accept a proprietary MRP XCG bash guard for optional extra protection. Full-housing cable routing for front and rear derailleurs using Niner’s bolt-on double housing clamps along top and down tubes complete the versatility. If you don’t need the guides, take them off and enjoy the clean look of theframe in singlespeed mode.
The oversized headtube of the ROS 9 allows the use of tapered fork steerer tubes that measurably reduce fork deflection, which means your Niner tracks straight and true. The full spectrum of riders from xc racers to all mountain shredders benefit from these features which is why we incorporate the technology in all our new frames. The ROS 9 Lets you take full advantage of increased steering precision as you get yourself into trouble. The hardtail for riders that don’t like hardtails. No twitchy high-posting around features you would hit on your “real” bike. No need to back off because your XC racing head angle prevents solid roosting. The ROS 9 won’t judge your lines - it lets you write checks your skills might not be able to cash, and what is more exhilarating than that? Short chainstays, slack head angle, and oversized headtube nourish these Roots of Steel - all with the ability to tweak the geometry via the BioCentric II. Run this rig singlespeed, 1x or fully geared with a front derailleur if you roll that way. Remove the cable guides and front derailleur mount if you don’t. Stealth routing for the dropper post keeps the ROS 9 fresh and clean. Sorry, the ROS 9 is not compatible with heartrate monitors or training plans but it will certainly earn you some PRs when you do your part keeping the rubber side down. Ride Over S*!t – The new ROS 9 injects hardtails with a huge-ass dose of fun.
BIO-CENTRIC II BOTTOM BRACKET SYSTEM
The Niner BioCentric II makes adjustments easy across a wide range of gears and eliminates the need for adjustable dropouts, giving the cleanest possible solution for singlespeed use. No bolt on hubs, no chain tensioners cluttering your ride, no brake adjustments with gear changes. Additionally, BB positioning allows finetuning of geometry. Want shorter chainstays? A lower BB? Steeper or slacker seat angle? It’s all achievable with the BioCentric II.
The BioCentric II offsets the bottom bracket spindle 8.5mm from center, offering greater range of adjustment compared to a traditional EBB setup. More offset is a boon when changing gears without having to change chain length and it allows riders to make more noticeable changes to frame geometry. Reliable Function - Traditional EBB units are held in place with set screws that can become difficult to finely adjust over time, or expansion wedges that can deform the bottom bracket shell of the frame. Split bottom bracket shells that clamp an EBB can stretch or ovalize. The Bio-Centric II avoids these troubles by using two bolts to apply a clamping force on the outside edges of the BB shell, eliminating the possibility of ovalizing or indexing the shell itself.
|Rear Derailleur||SRAM GX 11SP|
|Rear Shifter||SRAM GX1 11SP|
|Brakes & Rotors||SRAM DB5, 180/160 G2CS ROTORS|
|Brakes Levers||SRAM DB5|
|Crankset||SRAM S1000 GXP 32T|
|Bottom Bracket||SRAM GXP|
|Cassette||SHIMANO XT M8000 11-42T|
|Chain||SRAM PC 1130|
|Handlebar||NINER FLAT TOP ALLOY, 710MM, NINER GRAPHIC|
|Stem||NINER ALLOY STEM, NINER GRAPHIC|
|Grips||NINER GRRRIPS L/O NYLON|
|Seatpost||NINER ALLOY SEAT POST, 400MM, NINER GRAPHIC|
|Saddle||NINER CUSTOM WITH CR-MO RAILS, NINER GRAPHIC|
|Wheels||NINER ALLOY, 110X15MM FRONT, 142 X 12MM REAR, NINER GRAPHIC|
|Tyres||MAXXIS IKON SC 2.35 F, 2.20 R|
As a company dedicated to 29ers since our beginning, we at Niner are proud of our geometry expertise. As you will see in independent review after review, our bikes are held to the highest ride-quality standards, across our entire line up.
For riders who fall between sizes we recommend sizing down for a more manoeuvrable ride or sizing up for more stability.