June 20 update: See more on-trail photos here…
This week, Bikerumor was fortunate to be among the cycling press invited by BMC to the unveiling of their new flagship cross-country bike: the striking FourStroke 01 29. Not only would we be among the first to see the 4in travel carbon fiber 29er, but as the launch was held in beautiful Lenzerheide Switzerland, we were also able to spend some quality time with the big-wheeled Swiss wunderbike. Hit the jump for more photos, details, and (most importantly) riding impressions…
While BMC describe the FS01 29 as being “performance oriented,” their description is intentionally broader than when used for a traditional 100mm travel cross country bike. While the 2,040g frame (size medium with all required hardware) could certainly serve as an attractive and efficient race bike, BMC want the bike to be suitable for epic days, marathon racing, and trail riding. Maybe not a rider’s only bike- but almost hopefully their most versatile.
To this end, the FS01 29 comes with a few features that might be a surprise on a 100mm, sub-5lb 29er. In addition to the PF90 bottom bracket, direct fit front derailleur, 12x142mm rear thru axle, and post mount rear brake, the FS01 29 sports tabs for an included chainstay-mounted chain tensioner, a Shadow+ rear derailleur, and internal routing for a dropper post (or remote shock lockout). By using reasonably short (445mm) chainstays, a long top tube (610mm medium, 635mm large), a 70-degree head tube, and short stems, the FS01 29 is intended to balance race course agility with trail riding stability. And to be a fun bike to ride.
BMC have partnered with Fox to take advantage of a specifically-tuned 2103 CTD (Climb-Trail-Descend) Factory Series rear shock and Float 29 suspension fork. As Factory Series components, these are the best that Fox can build- and both Kashima-coated parts work very well on the FS01. A linkage-mounted sag guide makes setup easy.
With recommended sag levels front and rear and very little rebound damping, the 22.8lb (plus pedals) BMC is an active bike, allowing the wheels to follow the terrain for both traction and comfort. The sort of near-vertical gravel grunts our jet lagged and oxygen-deprived group was subjected to early in the day are best handled with the rear shock in the moderately-active “Trail” setting- but everything else I rode felt best with the shock in the fully-open “Descend” mode. The suspension’s designed-in anti-squat characteristics kept the suspension from moving excessively as long as I wasn’t flailing around, while somehow making the TF01 29 feel like it had another inch of travel.
Given a somewhat high bottom bracket (40mm below the axles), I found myself able to pedal through some truly nasty rock and root sections without a strike. When things got truly steep, it was only the 29×2.0 Conti Race King tires, and a low handlebar that kept me from treating the big-wheeled BMC like it was a longer-travel bike. When riding a medium (I’m 6’0 and could go with either a medium or large), the FourStroke’s playful personality is hard to resist: on rolling and technical trails, it was hard not to notice much of our group of riders boosting off of little lips and rollers. No doubt thanks in part to its light weight, the FS01 is eager to take flight- and happy to change direction in the air.
As going up a size calmed the bike down a bit (something that could have been addressed with a 70mm stem instead of the stock 80mm), I have to say that I preferred the smaller frame. 
It did require a bit of attention to keep the front wheel from wandering on truly steep pitches, but that seems a small price to pay for the medium’s more engaging ride and is no worse than most 140mm travel bikes.
True to its all-day intentions, the FS01 29 comes spec’d with a sensible mix of light (but not too light) components. The Shimano XTR 3×10 drivetrain with Shadow Plus rear derailleur makes sense given the big wheels (XTR doubles start with a tall 26t granny) and the XTR Race disc brakes (with 180mm rotors) have a fantastic lever feel. The Easton carbon bars and seatpost are proven while the tubeless EA70 wheels are light and sturdy without being crazy expensive. The lightweight Race King tires were no one’s choice for rocky Alpine riding- but roll well and will do just fine most everywhere else. A carbon-railed Fi’zi:k Tundra saddle is an appropriately posh perch for BMC’s off road range-topper.
Given BMC’s stated goals of building a fast, efficient, and capable machine, our day together suggests that they’ve succeeded. The suspension tuning is certainly to my liking- active without being overly so. More impressive was the fact that the sub-23lb 29er never really felt out of its depth in rock gardens and root fields for which it couldn’t have been designed. I suspect that my test bike’s wandering front end could be cured with some cockpit tweaking (or by paying more attention)- but given my aversion to climbing near-vertical fire roads, is probably not be an issue back in the real world. While some racing purists may be disappointed with the lack of abuse that the rear suspension doles out, marathon and all-day riders will find themselves feeling fresher and happier at the end of a big ride.
At $6,500, the FS01 makes a compelling case for itself as the ‘one bike.’ Given BMC’s permission to run a 120mm fork and the provisions for a dropper post and chain guide, I can’t help but think that it would be a lot of fun to see one in trail guise- the rear suspension certainly seems up to the task. With a half-carbon/XT FS02 29 and an all-aluminum/SLX FS03 29 in the works for MY13 delivery, all-day riders and racers in technically challenging areas should absolutely consider setting up a test ride. BMC are expecting the FourStroke FS01 29 to be in shops this fall.
marc
Action shots courtesy Martin Bissig / BMC
