Quick Review: New Niner SIR9 Steel 29er Hardtail Ridden, Weighed & Photo’d

I should get two things out in the open: I’m a fan of Niner’s bikes, and I’m not generally a fan of hardtails anymore. I’ve been riding full suspension for a decade now, and there’s no turning back for me.

That said, the new SIR9 steel hardtail is a pretty darn nice bike. Beyond the attention to detail and trick tubing on the frame, it’s just a pretty fun bike to ride. My test ride was at Deer Valley’s lift-served trails, so most of the riding was stuff that I had just previously ridden on a Cannondale Scalpel 29er and would soon be riding on a Jeckyl. In other words, there were plenty of spots that favored full suspension. Despite that, the SIR9 handled itself quite well, and I was even able to pull away from a few of the other riders aboard much more aggressive bikes.

FRAME DETAILS & BIKE WEIGHT

Complete bike weights are 24.6lbs for a geared bike with suspension fork and 20.3lbs for the singlespeed with Niner’s carbon rigid fork.

The white frame is quite pretty, shown here in XL as a rigid singlespeed. Niner has a demo tour partnership with Hayes, so bikes are outfitted with some mix of their products, in most cases that means a minimum of their excellent Black Flag wheels.

The headtube is 44mm, letting them run either internal straight or external tapered headsets. The seat- and chainstays are 3D works of art and, along with the bent downtube, are the result of a collaboration with Reynolds.

Numerous little features will escape most people’s attention, but they really make the bike special. The gusset under the top tube is flat in the center, which is just barely visible. This adds more strength and rigidity despite the thinner steel tubes. The downtube gets a bend to provide proper tire clearance and let them space the top- and down tubes’ contact points on the headtube farther apart for a stiffer front end. What’s just barely visible is the butting at the front of the downtube. Click to enlarge and you can barely make out the thicker section just in front of the bend.

In addition to lateral bends, the seatstays on the smaller frame sizes get a drop bend at the rear to clear the internally mounted disc brake caliper. The XL is tall enough to keep them straight.

Bullet shaped brake mounts are pure art.

Custom dropouts add a bit of flair. At left, the dropouts before they’re welded onto the frame and the derailleur hanger. On the right, the singlespeed insert.

An inside look at the chainstays and oversized BB shell. Niner’s BB inserts are available for standard or geared, and all frames have front derailleur cable guides.

RIDE REVIEW

Compared to Niner’s extremely stiff AIR9 Carbon, the new SIR9 is cush. The “lively ride” so commonly associated with steel bikes is immediately evident. It provided a great trail feel and slightly muted the rocks and drops. That was helped by running lower tire pressure, but the psi was similar to how I set it on my personal Jet9 RDO…until the end of the ride, when the rear tire developed a slow leak that finished all but flat.

Normally I ride a Large Niner full suspension bike, but for the SIR9, the XL felt better. Even with the taller bike, it was still easy to whip around. I could drive it into a corner and it would spring out the other side. It’s weird to think that a bike can have enough give to smooth out the ride yet not feel squirmy, but it does. It does it on rough straight sections and it does it in the curves.

Stand up to hammer and it’s plenty stiff to get you from A to B quickly, but without beating you up. One good test is standing and coasting over braking bumps. If you feel every little bump harshing your feet’s mellow, it’s stiff. With the SIR9, the harshness itself gets mellowed a bit. Seated hammering or climbing feels lively if just short of springy. Some of that has to do with their RDO carbon seatpost, which is designed to flex fore/aft to take the edge off. Combined, the post and frame do wonders for basic comfort.

Niner’s handling is spot on IMO, and the new SIR9 is a point and shoot bike. If you’re confident enough to look further down the trail, it rewards you with stable handling, but can wiggle through the tight stuff, too.

I’m not the target customer for this bike. But, of my friends that ride hardtail 29ers, many of the SIR9’s characteristics seem to fall in line with bike traits they like. If you’re a hardtail fan but don’t need the stiffest, efficiency-above-all-else race bike, the SIR9 is worth a test ride.

Action photos credit goes to Billy Michels Photography.