The Fourstroke 01 Three Shows That Long, Low, And Slack Isn’t Just for the Big Bikes
The Takeaway: The Fourstroke 01 Three is a 100mm bike that climbs almost as well as a hardtail and descends like a much bigger trail bike.
A 100mm Premium Carbon frame with an uncharacteristically (for XC) slack front end
Industry-first integrated dropper post
Budget-conscious components and suspension
Price: $5,299
Weight: 27.1 lb. (XL)
In response to the increasingly technical nature of modern XC racing, BMC went back to the drawing board to create a new style of cross-country bike for the new style of competition, and the Fourstroke 01 Three is the cheapest full-suspension XC bike to come out of this complete overhaul. Unlike other trimmed-down editions of top-flight steeds, this one boasts some of the same features as its top-tier relative; namely the Fourstroke 01 Three has the same Premium Carbon frame as the pricier Fourstroke 01 One. Another surprisingly high-end feature on a bike at this price is the first truly integrated dropper post that BMC calls the Race Application Dropper, or RAD for short. This oval post hides the dropper mechanism entirely inside the frame for a clean, sleek look.
BMC Fourstroke 01 Three Details
Style XC
Material BMC 01 Premium Carbon
Travel 100mm
Fork 100mm Fox Float 32 SC Performance
Shock Fox Float DPS Performance Elite Evol
Drivetrain SRAM NX Eagle
Wheel Size 29 in
Wheels Alex MD 25 rims with Shimano Deore hubs
Tires 2.25-inch Vittoria Barzo Graphene 2.0, tubeless ready
Tire clearance 29 x 2.25 in (could possibly squeeze in up to 2.3 in)
Crankset 174mm SRAM X1, 34t
Cassette SRAM NX Eagle, 11-50
Brakes Shimano MT 500
Saddle Fizik Antares R7
Seatpost 80mm BMC Race Application Dropper post
Handlebar 750mm BMC MFB 02
Stem 70mm BMC MSM 01
While the dropper is cool, this bike’s real calling card is the radical new geometry for an XC machine. Long, low, and slack has been the name of the game for long-travel bikes for some time, and now it’s shifting to XC in response to the increased technical demands of modern courses. A 67.5-degree head angle, 75.6-degree seat angle, 44mm of bottom bracket drop, and a 777mm front center (size XL) make for a bike that’s spunky uphill and nimble on tight turns, and that descends like a long-travel trail bike. The SRAM NX Eagle drivetrain may, at first glance, appear to be a mismatch as it’s normally not found on bikes at this price, when comparing the Fourstroke 01 Three to other bikes in the same price range, but it makes sense that BMC cut back somewhere since it gave the Fourstroke 01 Three a primo carbon frame while most NX- and GX-level bikes have a second-tier carbon frame. Suspension comes courtesy of a 100mm Fox Float 32 SC Performance fork and Fox Float DPS Performance Elite shock, and the bike rolls on aluminum Alex MD 25 wheels. They’re heavy and mask the Fourstroke 01 Three’s true potential, but a lighter pair of aluminum wheels will be enough to fully realize the amazing benefits of this short-travel rig that rides like a big, bad trail bike.
Top-Shelf Carbon and Integrated Dropper Post
As mentioned above, many brands downgrade to a heavier carbon frame at this price, yet the Fourstroke 01 Three touts the same Premium Carbon frame as its pricier counterparts. Another standout is BMC’s aforementioned proprietary RAD dropper post. BMC asserts this is cycling’s first fully integrated dropper post, with the entire mechanism hidden inside the frame. Besides being lighter (345 grams, compared to 493 grams for a 100mm Fox Transfer Factory post or 560 grams for a 100mm RockShox Reverb Stealth B1) and sleeker than other dropper posts, the RAD has an oval shape (instead of circular like a standard post) that BMC says makes it stiffer than a standard seatpost. The oval shape also helped the brand shave some weight by reinforcing the front and back to resist flex and trimming material from the sides where extra strength isn’t as needed. Both the Fourstroke frame and the dropper post are compatible with the Autodropper system BMC has been testing on the World Cup circuit this summer. In a major departure from how these devices typically operate, the Autodropper doesn’t require the weight of the rider to lower the saddle–when the rider presses the remote lever, a pneumatic chamber inside the frame releases air to lower the saddle. It’s still in the testing phase, but if it gets released to the public, anyone with a current Fourstroke 01 frame will be able to upgrade to the Autodropper.
5 Things We Love About The BMC Fourstroke 01 Three
Another feature tucked into this frame is internal cable guides. Full-length guides mean that you don’t have to slide cable housing in one end of the frame and delicately try to weave it through the bike, hoping it comes where it’s supposed to on the other end. There’s no functional impact on performance, but the pain-in-the-ass factor is reduced exponentially when servicing shift cables and brake lines.
A 100mm Fox Float 32 SC Performance fork offers a level of performance that’s in line with the SRAM GX Eagle drivetrain, and rear suspension comes courtesy of a Fox Float DPS Performance Elite Evol shock, which works well once you get the sag and damping set properly. A DT Swiss three-position, cable-actuated lockout remote allows you to switch between open, drive, and fully locked out. When fully locked out, the bike is as close to rigid as possible without risk of blowing out the seals on the suspension, and the firm setting is perfect for rough fire road climbs where you need maximum pedaling efficiency but still want a little travel to smooth out the ride.
SRAM NX Eagle Drivetrain
BMC continues the budget-conscious trend for this bike with its choice of drivetrain for the Fourstroke 01 Three. SRAM’s NX Eagle is functionally as good and slightly heavier than the GX Eagle drivetrain common on other bikes at this price. In many cases those bikes don’t have top-tier carbon frames, but they do have either components or suspension that represents an upgrade relative to the Fourtroke 01 Three. (One notable exception is the Norco Revolver FS 1 100.) The NX Eagle drivetrain uses an 11-50 cassette, which lacks the 10-speed low gear of higher-level Eagle groupsets. Up front, racers will appreciate the 34t chainring on the SRAM X1 crank. If a 34x11 doesn’t give you enough of a go-fast gear for your liking, upgrading to a SRAM GX Eagle or a higher-level cassette will give you that 10t cog. Since we are talking about a 1x-specific frame, BMC includes a chain keeper, but it can be difficult to align properly. You may need to take it off or purchase a better one.
Stopping power comes from Shimano’s MT500 brakes, with 160mm rotors on the front and rear for the small and medium sizes, while the large and XL bikes get a 180mm rotor in the front to accompany the 160mm rear rotor.
The Fourstroke 01 Three rolls on Alex 25 aluminum wheels laced to Shimano Deore hubs and wrapped in 2.25-inch Vittoria Barzo Graphene 2.0 tires. Functionally these wheels get the job done, but only just. They’re so heavy (3,969 grams with the Vittoria tires, sealant, rotors, and NX cassette) that they overshadow literally, and figuratively drag down the rest of the bike. In fact, they obscure all but the faintest hint of what the Fourstroke 01 Three is truly capable of—climbing prowess is muted and when descending the bike and wheel combo has all of the grace of an old Volkswagen barreling down the highway at 100 miles per hour.
In order to truly take advantage of the performance benefits of this bike, you'll need to upgrade to lighter wheels. In the process of testing, and in an attempt to isolate factors, I put on a set of carbon Bontrager Kovee XXX wheels (2,608 grams with Specialized Ground Control front, Fast Track rear, sealant, rotors and XX1 Eagle cassette), and immediately the bike transformed from a clunky ride that showed hints of greatness to one with which I’d be happy to toe the starting line. You won’t need to go to the extreme of putting on a $2,400 wheelset to bring out the beauty in this bike—a pair of aluminum hoops from brands like Stan’s, DT Swiss, and Industry Nine will shed a lot of weight, turning the Fourstroke 01 Three into a lightweight XC rocket ship. However, the cost of new wheels erases most of the budget-friendly aspects this bike was clinging onto.
Fourstroke 01 Family
If your taste is a little more high-end than the Fourstroke 01 Three, the Fourstroke 01 One has all the bling your heart can handle—a 100mm Fox Float 32 SC Factory fork, a Fox Float DPS Factory Evol shock, a SRAM XX1 AXS drivetrain, and carbon DT Swiss XRC 1200 Spline 25 wheels. That pretty little package will set you back $10,999, though.
The Fourstroke 01 Two splits the difference, offering a blend of performance and value. That bike has a 100mm Fox Float 32 SC Performance Elite fork, a Fox Float DPS Performance Elite shock, and a drivetrain that’s a blend of SRAM XX1 Eagle and GX Eagle, to the tune of $7,499.
BMC also sells the frameset as the Fourstroke 01 FRS, with a Fox Float DPS Factory Evol shock, stem, and 80mm BMC RAD dropper post, for $4,299.
All bikes, including the frameset, in the Fourstroke family utilize the same Premium Carbon frame.
Long, Low, and Slack
The Fourstroke 01 series brings long, low, and slack geometry to XC racing. The 1,206mm wheelbase on our XL tester far surpasses both the Trek Top Fuel 9.8 SL (1,165mm) and the Specialized S-Works Epic (1,169mm), and the 67.5-degree head angle is much shallower than those two bikes, which come in at 70.9 degrees and 69.5 degrees, respectively.
To balance the slack head angle, the back half of the Fourstroke 01 Three tightens up considerably. Although 429mm chainstays aren’t dramatically shorter than what you’d find on a typical XC bike, it’s noteworthy when compared to 438mm on the Specialized. The slack front end is complemented by a steep, 75.6-degree seat angle that allows very good traction while seated. That steep seat angle and slack (by XC standards) head angle combination centers the rider nicely over the bottom bracket, and the raked out front end helps the 01 Three ride much bigger and ballsier than you’d expect from a 100mm bike.
Last but not least, the Fourstroke 01 Three also boasts a noticeably lower bottom bracket than most, with 44mm of drop. By comparison, the Trek has only 27mm of drop. That does add an element of stability while you’re ripping down rough trails, but riders who like to power over rough, technical features will have to contend with more pedal strikes than on other bikes.
A Rockstar Bike
The light, agile steering was apparent from the moment I hit the trails. The bike handled the tightest turns with astonishing ease, both uphill and downhill, and the slack front end lends the Fourstroke 01 Three a level of stability on steep, rocky descents not often found in XC bikes. Conversely, it’s one of the liveliest bikes I’ve ever ridden on climbs—the rear suspension felt like it was assisting, rather than hindering, my out-of-the-saddle efforts.
However, it took a little while to dial in the setup and ultimately different wheels to bring the best out of the Fourstroke 01 Three. Its low-speed handling and climbing prowess were hard to miss, but high-speed descending was, initially, very choppy and rough. After a lot of fiddling with suspension setup and tire pressure, and in an attempt to isolate factors (a Hail Mary of sorts), I put on a set of Bontrager Kovee XXX carbon wheels with a Specialized Ground Control front tire and a Fast Track rear. That dropped three pounds, and the Fourstroke 01 Three became a completely different, more agile bike. As I stood up on steep climbs and long grades, the bike felt spunky, not soft and spongy as some do when you’re off the saddle and stomping on the pedals. Best of all, I could really feel how well the Fourstroke 01 Three handled the rough, rocky downhills that are typical of eastern Pennsylvania singletrack. The long and slack front end made it feel like I could do no wrong as I straight-lined sections of trail that typically require more refined line selection. It also seemed to get me out of self-inflicted jams when I got too far over the front wheel. Gone was the chunky feeling when rattling down rocky trails, as was the heavy, sluggish feeling when trying to ride over logs.
The Fourstroke 01 Three rides much bigger than you think a 100mm bike should. Still, it’s a $5,300 bike that’s heavier than most in its price range, has a SRAM NX drivetrain instead of the more typical GX, and comes with weighty hoops that detract from the excellent frame design. BMC appears to be on to something with the geometry, but the value proposition is tough when you can pay the same amount of money for another bike that’s race-ready and much lighter right from the get-go.
If you’re eyeing up a new XC bike and already have a killer set of wheels tucked away in your garage, the Fourstroke 01 Three will serve you well. That doesn’t mean this bike shouldn’t be in the conversation if you don’t have fast hoops waiting in the wings. In that case I suggest taking one for a test ride to make your own assessment of the perceived value trade-off between the killer geometry and top-tier carbon frame versus the added weight of the wheels and components.
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