Push to new limits.
Unless you've been living under a rock, it'd be hard to ignore the current crop of hard-hitting 29ers that have come to market recently. Aggressive trail riders and enduro racers are finally catching up to what the cross-country set has known for years: big wheels simply cover ground faster and their rollover ability in rougher terrain is contagious. It just took a little longer for geometry numbers to get dialed in and for wheels, forks, and tires to reach certain stiffness levels and durability for a rowdier bunch. The latest bike to add to the mix, the Pivot Firebird 29 is happy slaying parks, smashing through repeated shuttle laps, yet is lightweight and efficient enough to do some serious climbing on earn your turn descents. Sounds cliché and we're sure you're tired of hearing about a do-it-all machine, but we defy you to take a spin on the Firebird Carbon 29 Race X01 Eagle Complete Mountain Bike and not have a smile on your face. When big wheels combine with 162mm of supple travel and modern long and slack geometry is thrown into the mix, you get an injection of speed and confidence as you charge down steep and burly terrain. There's no mistaking this Firebird for a welterweight XC machine, but armed with 29-inch wheels and efficient DW-link suspension, you'll be surprised just how capable this bike even with gravity's assist pulling you down the trail. Like all of the latest 29ers from Pivot, this Firebird features Superboost Plus rear spacing for super short chainstays contributing to a nimble ride and it affords huge tire clearance for 29er tires (up to 2.6in) or the ability to go 27+ if you're seeking the ultimate in traction.
The Firebird 29 borrows heavily for the design and geometry queues of the 27.5in Firebird and its Phoenix DH Carbon siblings, with long reach numbers and 45mm length stems across the board. The before mentioned short chainstays, sitting at 16.96-inches, thanks to the 12 x 157mm Superboost Plus spacing allow for snappy handling, quick power transfer, ease the lifting of the front wheel up and over techy climbs, and for those blessed with the talent, manualing. Also contributing to the climbing chops are its steep seat tube angle of 74.5 to 75-degrees (based on its adjustable flip-chip position and lower headset cup selection) which places you right on top of the pedals and eliminates a wandering front wheel on steep switchback climbs, while its adjustable 65.5 to 65-degree headtube angle lengthens the bike's wheelbase providing excellent stability that gets better the faster you go and the steeper and rougher the terrain gets. Growing the wheelbase and getting the front wheel too far out in front of the rider has diminishing returns if you can't properly weigh the front tire for proper traction, so Pivot specs a fork with a 44mm offset that allows you to reap the benefits of a slack head tube while getting the front wheel a little closer to the steering axis. The headtube also accommodates an optional 17mm lower headset cup that is beneficial when swapping between wheel sizes or further fine-tuning the geometry.
As with all of its full suspension frames, this Pivot Firebird 29 receives the much-lauded DW-link suspension platform. Two things you'll really be looking for in a bike that is sporting nearly 6.5-inches of travel are supple stroke and efficient pedaling and the DW-link provides both in spades. You'll find that its travel is plush off the top and feels very linear, almost coil-like, with plenty of ramping at the end stroke so you don't blow through the travel while also providing plenty of support to reduce the dreaded mid-stroke wallow allowing it to pedal in a way that you've never experienced on a 160+ millimeter bike. DW-link also affords a fully active suspension, even under braking, and unlike some designs, it doesn't tend to hang up on square-edge hits so you can plow up and over ledgy, rock faced and rooty terrain without losing momentum making technical climbing enjoyable and fun. Spring and damping duties are handled by FOX's metric X2 shock and join the Phoenix DH inspired upper and lower links which are super wide and beefy and also tie together the dual upright swingarm supports adding impressive amounts of frame stiffness and durability. Also worth noting is that the flip chip on the upper link that alters the frame's geometry doesn't affect the shock rate, so you can dial in the geo for the riding on tap without having to fiddle with your shock settings.
We made mention of the rear dropout spacing above and we think it's worth mentioning again for those unfamiliar and even for those that are because there are plenty more bikes in the pipeline that will be sporting Superboost Plus spacing soon. The wider axle spacing allows the hub's flanges to push further out helping to better even the spoke tension on either side of the rear wheel and the improved bracing angles build up a 30% stiffer rear wheel. The other added benefit of the wider spacing is it allows for shorter chainstays that still play nice with wider rubber. You might be thinking that the wider dropout spacing splays the chainstays out further and it becomes an easier target for heel strikes, however, Pivot addresses this with clever tube shaping and we can attest that on a recent ride we experienced zero interactions with the chainstays despite using the same pedal and shoe combo and getting the occasional strike on our own personal non-Superboost Plus rigs.
Pivot realizes that building a great bike requires a holistic approach and all the components on its builds are very similar to ones we would select if we were building the frame from the ground up. This Firebird 29 Race X01 Eagle build gets the FOX Float X2 Performance shock to soak up trail chatter and big hits. It's highly adjustable and tuned specifically for the DW-Link's kinematics, and has two settings so you experience a bottomless feel when bombing descents, and with a flip of a switch, a firmer mode offers support up the fire road climb so you can do it all again. Up front, the FOX 36 Performance fork's burly chassis and oversized stanchions offer sure-footed tracking through ruts, roots, and bombed out braking bumps. Other features include a mix of SRAM's Eagle drivetrain, offering range for days offering enough gear to get to the top of the climbs without spinning out on the way back down and finding the perfect gear for all of the ridgeline riding in-between. We like Shimano brakes and so does Pivot, so it bucks the all-from-one-company group convention and specs Shimano SLX levers and calipers offering top-notch power and modulation. A Sun-Ringle Duroc wheelset with 30-millimeter inner width plumps up the Maxxis Minion rubber that works so well across different terrain. Finally, the Firebird 29 is given another callback to its Phoenix roots with the Phoenix finishing kit that includes its aluminum bar, 35mm clamp stem, and Padloc grips. And since Pivot knows they built this bike for a rowdy crowd, scuff-guards are included on the downtube/bottom bracket area and drive-side seat and chainstays so your carbon bike stays well protected, looking like new, and is quiet as you up your game deep in the woods or in the park.
- A 29in gravity machine with a penchant to climb
- 162mm of linear DW link suspension for cushy descents
- Slack 65.5 to 65-degree head tube allows stable tracking
- Stay planted and powerful climbing with a 74.5 to 75-degree seat tube
- SRAM Eagle drivetrain offers huge gear range and bail out cog
- Sun Ringle Duroc wheels are durable and offer a wide rubber platform
- FOX Float DPX2 Performance rear shock is adjustable, supportive, and supple