2017 BMC Fourstroke 01 XT Bike
2017 BMC Fourstroke 01 XT Bike
BMC’s Fourstroke 01 is a full-suspension cross-country bike that you’ll be as happy to take up the mountain as down. At 2040g for the frame, including all the hardware, it’s about as light as you can have a full-suspension bike, and have it still do its job.
The job it is designed for is to carry BMC pro riders to victory in the most demanding cross-country races in the world. And it has succeeded at its mission.
The Fourstroke 01 is the rare 29er full-suspension bike that competes at basically every World Cup event. The bike is light enough to compete with hard tails and the BWC helps position the wheels in such a way that they’re never a liability.
Weight is minimized thanks to generous use of carbon-fiber. Both the frame and the rear end are made of the stuff. As is BMC’s wont, they’ve not only shaped the tubes, but controlled the layup to maximize torsional stiffness and vertical compliance. You see it in how the top and down tubes are flattened, with more material aligned horizontally than vertically. You see it in the 1 1/8” to 1 1/2” tapered head tube. You see it in the BB92 bottom bracket.
BWC, Big Wheel Concept, is the first point of thinking. This is BMC re-thinking geometry to maximize the benefits of 29ers while minimizing any negatives. The result is an agile climber that is as comfortable picking lines while crawling uphill as it is ripping up an open descent. The keys are lower bottom bracket, longer top tube, shorter head tube, and more relaxed head angle.
APS, Advanced Pivot System, is how they isolate the pedaling inputs from the trail-created inputs. The suspension is active whether you’re pedaling or coasting. And to tune it perfectly, you just sit on the bike and look down at the swing arm to find the Initial Load Indicator. Machined and painted lines on the arm that allow you to figure out where neutral is, and then tune for firm or soft. The linkage is machined and moves on oversized pivots to make sure there’s no slop laterally, and the vertical movement is as smooth as can be.
Suspension elements are essential to the perfect working of the frame, and BMC has partnered with Fox to provides their World Cup-ready bumpeater. The shock gives you 100mm of travel, in a very tunable Float DPS with Kashima coating to remain as friction-free as possible. It has a CTD, Climb Trail Descend, damper that you can adjust on the fly.
The frame is also set up with lots of classic BMC features. Natural-born postmount is how you mount the rear brake. The threaded inserts are replaceable. The standard position is set up for 160mm rotors, but can be adjusted for 185mm rotors. There’s a chain guard atop the bottom bracket, and an anti-chainsuck plate on the right chainstay. The cables get routed under the downtube, where they can easily be serviced. The frame also comes with a set clamp. You provide the post. The frame is set up for internal routing of a dropper post, should you choose to go that way.
The BMC Fourstroke 01 is a World Cup-ready full-suspension cross-country bike that not only outperforms hardtails and full-suspension rigs, but takes you into a realm where anything seems rideable.
Bottom Bracket Shimano
Brake Calipers Shimano XT
Brake Levers Shimano XT
Cassette Shimano XT, 11-40
Chain Shimano XT
Crankset Shimano XT, 36/26
Fork Fox Float 32 SC, Performance Elite, FIT4, Remote, 100mm
Frame Material 01 Premium Carbon (F&R), DTi
Front Derailleur Shimano XT
Handlebar BMC MFB 01 Carbon, 720mm
Pedals Not Included
Rear Derailleur Shimano XT, Shadow Plus
Rear Suspension Fox Float DPS, Perfomance Elite, Evol, Remote, 100mm
Rotors Shimano XT, 160mm
Saddle Fizik Tundra M7 Versus
Seatpost BMC MSP 01 Carbon
Shifters Shimano XT
Stem BMC MSM 02
Tires Continental: X-King (F) / RaceKing (R), Performance Silver, 29×2.2
Wheel – Front DT Swiss XR 1501 Spline ONE
Wheel – Rear DT Swiss XR 1501 Spline ONE
|Size||Seat Tube (c-c)||Seat Tube (c-t)||Top Tube Length||Head Tube Length||Chain Stay Length||Seat Tube Angle||Head Tube Angle||Stand Over Height||Wheel Size||Stack||Reach|