Light the hill on fire.
The secrets out, 29ers make for excellent bikes on aggressive trails and for enduro racing. While cross-country racers clamored to 29-inch wheels well over a decade ago favoring the big wheels for their ability to cover ground faster and offer improved momentum and rollover ability in rougher terrain, wagon wheels took a little longer to catch on with the more gravity oriented riders as geometry numbers still needed sorting out and wheels, forks, and tires had to reach certain stiffness levels and durability needed for more aggressive riders. The latest bike you can add to the mix, the Pivot Firebird 29, is just as happy as you are as it heads up on a lift to the top of the mountain, resting on a tailgate pad for the 4th shuttle lap of the day, or patiently waiting at the trailhead ready to stretch its lightweight and efficient legs up some serious elevation where the terrain and sights are choice and always worth the effort. We know the industry is rife with do-it-all, quiver-killing machines, but it only takes one ride to appreciate what Pivot has done with the Firebird Carbon 29 Pro XT/XTR Complete Mountain Bike. Big wheels conspire with the 162mm of supple travel and modern long and slack geometry for speed and confidence on steep and burly terrain that used to require a full-on DH bike. And unlike most bruisers, with those 29-inch wheels and ultra-efficient DW-link suspension platform, you'll quickly realize that climbing isn't such a chore after all and you'll be looking for the more epic routes. As with the rest of the current crop of 29ers from Pivot, this Firebird features Superboost Plus rear spacing for super short chainstays contributing to agile handling and huge tire clearance for 29er tires (up to 2.6in) or the ability to go 27+ if you're seeking the ultimate in traction and floatation.
The Firebird 29 is a spitting image of the 27.5in Firebird and its Phoenix DH Carbon siblings, running modern long reach numbers and spec'ing 45mm length stems across the board. The before mentioned short chainstays, sitting at a stubby 16.96-inches thanks again to the 12 x 157mm Superboost Plus spacing, allow for playful handling, quick power and weight transfers, and eases the lifting of the front wheel up and over techy climbs. Those climbing chops are further aided by its steep seat tube angle that ranges between 74.5 and 75-degrees, based on its adjustable flip-chip position and lower headset cup selection, placing you directly on top of the pedals and helps eliminate that wandering front wheel as you negotiate steep switchback climbs. Contrasting the steepness of the STA is its slack and variable 65.5 to 65-degree headtube angle which lengthens the bike's wheelbase and provides excellent stability that you'll quickly learn to trust as you begin to increase your speed on steeper and rougher terrain. But if you grow that wheelbase too much, you'll get the front wheel a touch too far out in front of the rider which quickly diminishes returns as you can't properly weigh the front tire for the traction needed, so Pivot specs a fork with a 44mm offset allowing you to reap the benefits of that slack head tube while it gets the front wheel back 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.
Since its incarnation, all full-suspension Pivots, including this Firebird 29, have utilized the much-lauded DW-link suspension platform. It simply provides Pivot the ability to tune the nearly 6.5-inches of travel for a supple stroke and efficient pedaling. 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 of its stroke so you don't quickly blow through all of the travel. Additionally, it provides plenty of support that reduces the dreaded mid-stroke wallow that manifests itself as pedal bob, so you end up with a super capable ride that pedals unlike anything you've experienced on a 160+ millimeter bike. DW-link also affords a fully active suspension, even under braking, and unlike some designs, it doesn't have some weird wheelpath that wants to hang up on square-edge hits so you can plow up and over ledgy, rock faced and rooty terrain without losing momentum that makes technical climbing enjoyable and fun. Spring and damping duties are handled by FOX's metric Float X2 shock that’s join together with the Phoenix DH inspired upper and lower links featuring super wide and beefy construction and along with the dual upright swingarm supports, expect impressive amounts of frame stiffness and added shock 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 that builds 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 works closely with its component partners for its build kits and it results in a better complete bike that utilizes the latest technology and packs in a ton of value. This Firebird 29 Pro XT/XTR build gets the FOX Float X2 Performance shock that soaks up trail chatter and big hits with aplomb. 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 over again. Up front, the FOX 36 Factory 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 Shimano XT and XTR, offering the range we're after on those long days with plenty of climbing with enough overdrive so we're not spinning out on the way back down and we always have the right gear for all of the ridgeline riding in-between. This build also gets Shimano's 4-piston XT calipers and levers which offers top-notch power designed to quickly halt an e-bike with modulation to boot. The DT Swiss M1700 wheelset has a 30-millimeter inner width to plump up the Maxxis Minion rubber that works so well across different terrain and Pivot even upgraded its stock 18t star ratchets for 36t for quicker engagement that we're sure is valued for the kind of riding close to its Tempe, AZ home base. Finally, the Firebird 29 is given another callback to its Phoenix roots with the Phoenix finishing kit that includes its Team carbon bar, 35mm clamp Team Enduro 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 frame stays well protected, looking like new, and is quiet as you up your game deep in the woods or in the park.
- A 29er enduro rig that's capable up and down
- Long, slacked-out 29er geometry lets you push limits
- Light, stiff carbon frame comes in at 7lbs with shock
- 65.5 to 65° head tube angle and 44mm fork offset provides stability
- 75.5 to 75° seat tube angle keeps you over the pedals
- 162mm of plush and efficient DW-Link travel
- Beefy Pheonix-inspired links are torsionally stiff
- FOX X2 shock and 36 fork keep you glued to the trail until you're ready to go airborne