Niner S.I.R. 9 - 2014 Review

Niner S.I.R. 9 - 2014 for Sale

Backcountry : Niner S.I.R. 9 - 2014 Features & Description

Aside from an occasional oddball, like magnesium or something from the kingdom Plantae, material choices for mountain bike frames are aluminum, steel, and carbon fiber. Each one has distinct advantages and disadvantages, and the amount of time that's been spent deviling into their nuances is unfathomable. But, based on common deductions, there are solid reasons why Niner would continue to offer an updated SIR 9 among its carbon and aluminum 29ers.

The SIR 9, along with the alloy AIR 9, launched Niner into mountain biking's limelight. And it's hard to believe that the SIR 9 is already approaching eight revolutions of the big yellow orb since it began humiliating bouncy bikes with lesser wheels. In that time, we've seen carbon eclipse ferrous and aluminum chassis due to gram counters' love affair with fibers and epoxy. But, steel still holds its own when it comes to ride quality and value.

Most manufacturers pick either aluminum or steel for a price-point line. Niner chose to use both -- alloy for its entry level line, while reserving steel for the seasoned rider who can appreciate its distinct ride characteristics, and who doesn't need to drain a bank account on a carbon rig to chase KOM's. If you're not up to speed on the differences between steel and aluminum, the quick and dirty is that aluminum is intently stiffer and lighter, so it tends to accelerate quicker, but it can be more fatiguing due to vibration -- imaging holding onto a jackhammer all day. Steel, on the other hand, dampens trail chatter and has a natural spring-like nature that results in lively and encouraging handling on singletrack. In this case, Niner uses proprietary Reynolds 853 tubing with custom S-bend rear seatstays and chainstays. The tubing's wall thicknesses, including the down tube and top tube, are tweaked both externally and internally to produce the best possible ride quality for each frame size.

Clean TIG welds provide the strength, while short chainstays and a steep head angle offer the maneuverability that tight, twisty trails require. Niner also gave the SIR 9 a radically sloping top tube for plenty of stand-over clearance in all its sizes. From the beefy tire clearance to the down tube shaped to avoid interference with fork crowns, everything about this frame shows the design time invested. And because of this extensive R & D, and willingness to use new standards and technology that benefit 29ers, Niner's developed a reputation for being ahead of the curve. Good luck trying to find another steel frame that has 142mm rear spacing, a post mount rear caliper, and the option to run just about any drivetrain configuration out there -- from single speed to multi-speed.

The SIR 9 features Niner’s exclusive Bio-Centric EBB technology. An essential design element of the Bio-Centric system is that the cups lock to the bottom bracket shell’s flange. Once the EBB is in position, one bolt tightens the eccentric to the flanges, providing 360 degrees of purchase, while eliminating any chance for creak-causing dirt or debris to contaminate the interface. Also, because forces are no longer placed against the inside of the shell, it won’t round out or suffer from the over-tightening issues of traditional EBB designs.

This simple solution makes the SIR 9 the true Zen-machine that SS bikes should be. The wheel can be removed without hassling with the caliper position or chain tension, and you’re guaranteed perfect dropout-to-frame alignment -- unlike individually adjustable sliding drops. All that you need to do to set up the SIR 9 for gears is to add the derailleur hanger dropout and swap the EBB for one of Niner's CYA press fit adapters.

If you plan on going the geared route, Niner recommends doubles not exceeding 26/39 chainrings for SRAM, and 28/40 for Shimano. However, a standard triple will pose no problems. The rear triangle will accommodate a 2.4in tire, and you can run a 160mm rear rotor. You’ll need a bottom pull, high mount front derailleur with a 28.6mm clamp. The S.I.R. 9 uses a 27.2mm seatpost, a 73mm BB (only external style bottom brackets work with the EBB), and a 44mm tapered headset. It comes with a Maxle rear axle.

The Niner SIR 9 is available in the colors Arctic White and Tamale Red and in four sizes from Small to X-Large.