The 29er’s path to mainstream mountain bike rider acceptance has been a tough one. Their lack of parts, overly long, truck-like wheelbases, and toe overlap were just a few negative aspects that hindered the original generation of 29er bikes. Luckily there were some early adopters that took some risk, and while enjoying the benefits of larger wheels, they enviously watched as bike designers ironed out the original drawbacks and came up with new, frame and fork enhancing standards. Now mountain bikes like the BMC Speedfox SF29 have nimbleness that rival 26in-wheeled brothers. The Speedfox SF29 will not only be able to gobble rough terrain, but it will do so with amazing composure.
BMC didn’t rush into the 29er game; instead, it invested big into computer feedback and trail time to perfect the geometry and frame design. By using a computer technology called Finite Elements Method, every 6000-series aluminum tube has been formed to exact standards. The end result is a bike frame that reacts to inputs from the rider like steering, power application, and braking with precision. Not only does it have faultless performance, but the triple-butted, hydro formed tubing provides the Speedfox SF29 that sweet BMC silhouette.
While focused on optimizing strength and weight savings, the geometry is what allows these mountain bikes to shine bright on the trail. With a 70-degree head angle it offers quick turn-in without being too much at higher speeds. And the tapered headtube keeps the Speedfox pointed in the right direction by resisting front end flex. To build a modern, multi-link suspension system in the 29er application is difficult without ending up with a super-long wheelbase. So the designers have spec-ed a a direct mount front derailleur which allowed them to apply their lauded APS suspension as tightly as possible, giving the Speedfox 29ers a 445mm chainstay length to rail switchbacks.
They calculated the Advanced Pivot System pivot-point positions, so the Speedfox SF29 will give the efficient, plush ride BMC mountain bikes are known with. All your leg power is transferred into forward motion and not into compressing the 29ers rear shock. This design also promotes amazing traction when climbing on off-camber areas. The APS has 100mm of travel, which we feel is the perfect complement to the larger 29er wheels. Key to the design of the Speedfox’s handling are the front and rear oversized axles and precision cartridge bearings on all the pivot points. These ingredients matched with the optimized frame tubes offer a very flex-resistant core that extracts the most performance from its suspension.
A Fox RP2 controls the 29ers suspension movement. The efficiency of the APS suspension system is so good there’s no need for a complicated rear shock. The Float RP2 has rebound adjustment and the ProPedal switch for when you’re hammering on the cranks up climbs. They equiped the Speedfox SF29 with its own initial load indicator to simplify the sag setting, ensuring the best mountain bike suspension performance. They complement the rear suspension by using a 100mm Fox Float RLC with the FIT damper front fork with all the Fox tunable features. By using a 15mm quick-release will ensure the Speedfox SF29 goes where its pointed, and a lockout keeps out-of-the-saddle climbing bob-free.
The full suspension bikes have a cockpit with highly adjustable SRAM XO 2X10 shifters and ergonomic Avid Elixir 7 levers with carbon blades mounted on a BMC Scor MKII stem and handlebar. The Elixir 7 have 180mm rotors for plenty of leverage, cooler operation. The gearing is handled by an XO rear derailleur and an X7 front derailleur. The X0 crank’s 36/22 chain rings, offer perfect ratios for 29ers and trail riding without any excess. Light, stiff Easton EA70 XCT wheels are mounted with a 2.25in Schwalbe Rocket Ron at the front and Racing Ralph on the rear. A BMC Race seatpost with a Fizik Tundra saddle finishes off this performance-oriented build.
The Speedfox SF29/SRAM XO Complete Mountain Bikes are available in White, and with three total sizes: Small, Medium, and Large.
Speedfox SF29/SRAM X0 Complete Bike Price: $4499.00
The Speedfox’s are available at
The BMC Speedfox SF29/Shimano SLX 2012 Complete Bike
is available at Backcountry as well for