Words: Toni Walbridge
Photos: Toni Walbridge / Misti Walbridge

For 2014 BMC has completely revamped the Trailfox line to create a focused All-mountain / Enduro race platform. I must admit, BMC is not a brand that is typically on my radar but that’s all poised to change after this experience. There’s no question the Swiss carbon wizards make some impressive road bikes and XC mountain bikes but their presence in the gravity fueled side of the MTB world has been mostly non-existent until now.

With the Trailfox line, BMC basically started with a blank sheet of paper and set about building a machine designed to be fairly quick on the climbs but absolutely rule the downs. So what, right? What’s a bunch of hot-shot road and XC guys gonna bring to the Enduro race scene that everyone else hasn’t done already? Well, BMC went down a path that few others have just yet. Specifically, they created a frame that delivers on every major geometry wish list for aggressive All-mountain riding and then somehow managed to fit 29” wheels in there.

All said and done, the finished product brings a full 150 mm of rear wheel travel, extremely short (for a 29’er) 17.125” chainstays, a 13.5” bottom bracket height, and slack (for a 29’er) 67º head tube angle. All models in the Trailfox line share the same basic geometry with the differences being in the frame materials and component spec.

The TF01 Trailcrew model that we’re reviewing here is aimed at the crowd competing in the highest levels of Enduro racing and thus boasts a full carbon frame fitted with a full compliment of race worthy components. Some of the stand outs in the specifications list include a Fox Float-X CTD shock in place of the standard Float CTD, a full XX1 drivetrain, and monstrous Avid X0 trail brakes. Did I mention the ideal rider should be well funded? At an MSRP of $8,999 USD, the TF01 Trailcrew is not for the weak of wallet. Lets dig in a bit and see if it’s all worth it.

When it comes to long travel 29’ers there have been three key hurdles that have haunted 29er bike engineers for years. First, the rear end can become too long once you make room for all the extra travel. Even with chainstays at a full 18”, many longer travel 29’ers before the Trailfox struggled with clearance at multiple points. There are a variety of factors involved with solving this issue including the placement of suspension linkage, the shape and size of the yoke at the front of the chainstays, the seat tube angle, and the path the wheel takes. BMC has been able organize the rear of the Trailfox such that the chainstays are impressively short at 17.125” but almost as important is how they did it. The Trailfox is available in three sizes as well Small (pictured), Medium, and Large.

Geometry

Among other adjustments, BMC tipped the seat tube up to a full 74º. Traditionally that value falls somewhere around 71-72º but by increasing it to 74º they have moved the seat tube forward into a more straight up position. On a 150 mm bike like this, it translates into more weight over the front end while climbing and less wandering. It also means that the effective top tube length relative to the reach measures a bit shorter. To compensate for this, BMC then went and really stretched the reach out across the range. Now we have clearance in the rear, the top tube length required for seated climbing, and a roomier feel when you’re standing and charging. Brilliant.

That brings us to the next big hurdle which is front derailleur clearance. You see, even if you jump through all the hoops and figure out how to stuff that rear wheel in there nice and tight, you’ve now gone and introduced interference between the rear tire and the front derailleur. BMC managed to tackle this issue by mounting the front derailleur to the rear swing arm. This allowed them to position it out of harms way as it moves with the rear through its travel so that its location relative to the rear tire does not change. With some 29er bike designs, the tire can experience rubbing against the front derailleur.

Obviously, the Trailcrew spec of the Trailfox does not use a front derailleur but other models in the lineup do. And this brings us to the third and final hurdle, what to do about that tall front end. As 29er forks have crept up in travel so has bar height. Traditionally, a 150 mm fork has resulted in a tall stack height and bar to ground height which in turn compromises handling in a variety of ways. BMC managed to engineer some incredibly short zero-stack head tubes, just 90 mm tall for the small frame, that effectively deal with this challenge that plagues many 29ers.

On my test bike, even with the fairly tall Hans Dampf up front, I was easily able to achieve a bar to ground height of 40.5” which is right in line with a long travel 26’er and more than an inch shorter than some of the long travel 29’ers that I’ve ridden. This achieves a much more balanced ride in terms of climbing position and quickness when moving side to side. The latter has been typically labeled as just a facet to the 29” wheel itself but as it turns out it was more about the supporting geometry.

Another key consideration in this lower front end is that allows for a lower bottom bracket height while maintaining a reasonable stack measurement. Remember, the stack height is the vertical distance from the bottom bracket to the height of the head tube. Often, we see bottom bracket heights on 29’ers raised simply to keep the stack height in check which compromises handling in other ways. In summary, BMC has, more effectively than anyone else to date, eliminated many compromises in 29er geometry and handling to allow the rider to experience all the good (and the bad) that the 29” wheel has to offer.

The 17.125″ chainstays are worth highlighting again as it is such a game changer. But there’s quite a bit more going on back there. Note the two silver bolt heads on the rear triangle vertical brace. They serve as the mount point for a front derailleur. Along the chain stays, BMC has thoughtfully added a protector that doubles as a shifter cable guide and the mount for their house brand chain guide. The rear wheel mounts into now pretty much standard 12 x 142 dropouts. It’s worth mentioning that BMC built prototypes of the Trailfox in 26”, 27.5”, and 29” before settling on the new design.

The DT swiss XM1501 wheel set showed up with Conti Mountain King 2 tires with tubes installed. I was excited to find that the rims arrive taped and ready for a tubeless valve stem and a little sealant. I swapped in my preferred a Schwalbe 2.35 Hans Dampf up front and a Michelin Wild Race’r 2.25 out back. Both sealed up immediately and held pressure throughout the test with just 1 scoop of Stans. BMC went with all Fox suspension, including a Fox 34 Float CTD up front in 150 mm of travel. Fox has continued to take a simplistic approach to tuning and adjustment with the 2014 Float 34. There’s a 3 position compression knob on the top of the right leg for Climb, Trail, and Descend modes along with a rebound adjustment on the bottom of the right leg and a single schrader valve to fill it’s positive and negative air chambers on the top of the left leg.

BMC went with a 170 mm XX1 crank for the size small. I generally run 170’s on my DH bikes and 175’s on my trail bikes but I can’t say I noticed a heck of a lot of difference. You get a bit less leverage with the shorter arms but with the 28t chainring and generous spacing of the XX1 cassette, I never ran out of torque. Having dropped chains a few times on other XX1 setups lacking chain guides, I was was happy to see that BMC has supplied their own custom guide to keep the chain in place. Also, ISCG-05 mounts are available should you want to run a traditional chain guide or just a lower bash guard.

The Trailfox is spec’d with a quality cockpit all the way around. Saddle time is served up via a Fi’zik Tundra 2 saddle perched on a 150 mm Reverb Stealth (which can be a PITA to bleed compared to non-stealth versions). Up front a 55 mm Easton Haven stem clamps BMC’s house brand 750 mm carbon flat bar holding X0 trail bakes with match makers to mount the XX1 shifter and Reverb remote. Included are Lock-on grips that use only an inside clamp. They are easy on the hands for those of us that tend to grip our bars on the outer edge. I ended up swapping some wider Race Face bars into my setup.

That’s an ultra short 90 mm tall head tube on the Trailfox in size small with the medium and large sizes each incrementing 5 mm. This is a key accomplishment as keeping the front end low on a long-travel 29’er is one of the biggest challenges. An overly tall front end can detract from quick side to side handling as it can also require a higher BB to keep the stack measurement in the correct range. In the shot below I have replaced BMC’s stock flat bar with a 19mm rise Race Face SIXC bar which does fly in the face of the aforementioned benefits of a low front end. Unfortunately, the BMC bar at 750 mm was a bit too narrow for me to feel comfy on and I didn’t have a wider flat bar on hand. I later installed a Race Face Atlas flat bar at 785 width which brought my bar to ground height to 40.5″ which is right in line with a long travel 26er!

I tend to have mixed feelings about internal cable routing. I love the look but hate the complexity. BMC went with internal routing on the front triangle and external routing on the rear with full length housing. I wound up having to change the shifter housing as it was trimmed a bit short and routing a new cable wound up being quick and painless. There are a couple of small screws for the caps at each end of the frame that you need to be gentle with but otherwise, the cable fed through with ease. I did get quite a bit of noise out of the cables rattling around inside the frame at first but once I trimmed the cables a little shorter that mostly went away. Overall, I’d rate this one of the easiest internal routing setups to live with.

There’s a decent amount of mud clearance in the rear considering how short the chain stays are. That’s a 2.25 Micheline Wild Race’r which is pretty big for it’s stated size. It’s hard to tell in the pic below but there is a reasonable amount of side to side clearance should you knock your rim well out of true and need to finish out the day before dealing with it.

Considering the Trailfox’s credentials as a purebred racer and the fact that it’s constructed entirely of carbon fiber, it’s comforting to have a robust rock guard on the down tube to protect your investment. Also worth pointing out is the exit point for the internal routing. With The loops of cable are compact enough that I had no issues with snagging or damage.

Rear suspension setup on the Trailfox is a breeze with the built in sag meter. BMC actually provides a range of hard to soft rather than a single sag value. This feature makes it notably easy to make adjustments without a partner to assist. Once air pressure is set, the Fox Float X CTD with Trail Adjust is quick to dial in with a easy to reach rebound adjuster and a large lever to select the three compression settings; climb, trail, descend. The Trail Adjust feature sets the amount of low speed compression for Trail mode on a scale from 1 to 3. This is more of a set-and-forget feature and I favored setting 1 on the Trailfox.

All the cool Enduro racer kids are consicous of additional weight and tryo to come up with ways to ditch their pack in exchange for a minimalist supplies mounted (duct taped) directly to their bike. It’s the 80’s all over again! I have to admit to obsessing about this myself and fortunately so did the folks at BMC. They managed to make room for a full sized water bottle inside the main triangle of the Trailfox even on the size small. I did note that clearance is a bit tight, especially with the piggyback on the Float X taking up extra space. A standard bottle cage will work but I used an Arundel carbon side loader for style points (seriously? style points for a bottle cage?) and ease of access. I also managed to fit my emergency kit complete with tube, 2 CO2’s, gorilla tape, various pieces of small hardware, shifter cable, and a basic medical kit inside the front triangle as well. My inner gear nerd is elated.

From the non-drive side you have a clear view of BMC’s APS linkage and it’s positioning to help achieve the short rear end. Also of note is the 180 mm post mount for the rear brake. In my opinion, 160 mm rotors are just not enough to slow down the big wheels when you’re really getting after it. I’m happy to see BMC went straight for the ability to run a 180 rotor without an adapter. Weight weenies and lighter righters might be disappointed but I think it was the right move.

Keeping with the big brakes theme, that 4 piston SRAM XO Trail caliper grabs a full 203 mm rotor up front. Again, I think the rotor size speaks volumes for the intended capability of this bike.

Being a $9000 “super bike” I expected this thing to be feather weight. When I first dropped it on the scale bone stock except for the addition of my XTR pedals, I was a bit disappointed. Capability and durability have to be first and foremost but when you’re shelling out this kind of money, I expected to see more weight savings. At just over 28 lbs, the Trailfox was by no means portly, just not quite what I had in mind.

Tubeless saved a good bit of weight

With a quick swap to my preferred tires and a tubeless conversion, I was at much more respectable 27.5 lbs. It’s plausible to spin the lack of carbon wheels as a good thing, because there is more weight to be saved should you wannt to go down that road. It also could be considered a bad thing because at $9000 the exclusion of carbon wheels seems questionable. However you choose to look at it, if you’re on hell bent on a 26 lb ride, it is totally doable with the Trailfox as long as your wallet is up to it.

Riding the Trailfox TF01 Trailcrew

My first impression when I hopped on the Trailfox was that it didn’t feel as “big” as the last 150 mm + 29’er I rode, the Specialized Enduro 29. The bars felt like they were in the right spot, really nothing about the bike felt overly tall. Notably, the top tube clearance is absolutely generous, even for my 30” inseam. It just kind of felt like a normal bike. During the inital pedal-test I immediately noticed that despite it’s 150 mm of travel, pedaling performance is efficient and not at all mushy.

I adjusted the CTD lever on the Float-X shock a bit andquickly settled on Trail for rolling and moderate climbing angles. The Climb setting was used for sustained smooth steep climbing. It is on those steeper grades where the geometry-friendly pedaling position really started to shine. My weight balance remained decidedly forward with no hint of that “hanging off the back” feel that is common while climbing on long travel bikes without a travel adjust fork. This allowed me to relax my upper body and spin along comfortably.

I also noticed a distinct lack of wandering in the front end. With my weight forward, the front tire remained planted and moving in my intended direction with little effort expended on my part. Whether you’re racing or just out for a long trail ride and trying to conserve energy, this is a huge bonus. Pushing the pace harder on XC-style climbs, the travel and weight creeps in, reminding you that the Trailfox is not an XC racer.

Short sprints out of the saddle are well rewarded in technical sections but otherwise a seated, smooth cadence is preferred to get the most out of it. One bonus I noted regarding the Trailfox’s longer reach is that when sprinting out of the saddle I had no issues with contacting my knees into the bars, even when leaned forward.

The gear range afforded by the XX1 drive train with a 28t up front made for easy spinning up the steepest grades and I didn’t really notice 170 mm crank arms. I did manage to break the 11 speed chain a very long way from the car. Fortunately I found that a 10 speed KMC missing link worked just fine in a pinch to repair the 11 speed chain. I noticed no immediate issues with shifting or reliability throughout the remainder of the test.

I’m in the camp that love’s height adjust posts (aren’t we all now?) and found the 150 mm version of the Reverb to be even better than the 125 mm. A nit-pick on the matchmaker setup for the Reverb button is that the positioning is a bit awkward if you push your brake levers inboard for 1-finger braking. Even with fairly large hands I had a hard time reaching the Reverb button with my thumb without repositioning. Despite this minor quirk, I arrived at the top of familiar climbs quickly and feeling fresh aboard the Trailfox. A separate clamp could be used here to alleviate this but you’d loose the matchmaker setup of the single combined brake/Reverb perch.

But wait… there’s more! One thing that I’ve always felt 29’ers excelled at is efficient climbing through technical terrain. I’ve been on a very highly spec’d carbon 29’er as my personal trail bike for the past year and always felt like it just killed the ledgy climbs. Well, riding the Trailfox, I realized that I had become accustomed to pulling really hard on the bars and aggressively weight shifting to lift the front end. This is one of those efforts that’s no big deal at first by really wears you out on a long day in the saddle. Moab has a few million of the sort of ledges that are just a bit too tall, even for the monstrous 29” wheel, to roll up and over. On the Trailfox, you only have to just think of weight shifting and the front end comes right up. It’s literally the best of small wheel maneuverability combined with big wheel efficiency. Over the course of a couple long days in the desert I felt more full of energy as a result. I would rate this as a rather tremendous benefit on longer and more physically demanding rides plus it’s just a hell of a lot more fun.

Once the climb is over, that’s where the fun really begins. Descending on the Trailfox was a treat. Please excuse my hyperbole but the Trailfox is a “game changer” for the aggressive trail rider. The 29” wheels have finally become unhindered by geometry with their design. I split my time about 50/50 between the Trailfox and my dirt jumper so I know a thing or two about responsive geometry. This bike has it in spades. The Trailfox is literally one of the easiest trail bikes to throw around that I’ve ridden.

You can hang out in a manual all day through rock gardens, snap out of corners, and blast up and down ledges with the front wheel in the air. Rallying into to corners at completely irresponsible speeds, the low BB and quick handling front end get on line with authority and stay there. The XO trail brakes are easily some of Avid’s best brake to date delivering both modulation and ultimate stopping power. However, they do loose a couple points for inconsistency in the lever pull on the installed set. In the suspension department, the Float-X CTD was a stand-out performer. I found that once I had my air pressure dialed a bit to the firm side, I could actually use all three settings. Climb being mainly for road transfers and very smooth ascending, Trail for rolling climbing and fast descending where traction was good, and Descend for very low traction situations. Overall, the rear of the Trailfox is laterally quite stiff with a well damped feel that is slightly biased towards feeling efficient vs. plush which is just about right for racing in my opinion. If there was one thing holding me back suspension wise, the Fox 34 CTD fork is still a bit soft on the compression tune for charging steep lines.

I did what I could to compensate by adding more air and just leaving it in Climb all the time but I never did find my happy place. The thing about the tune on the 34 is that it’s probably just about right for the vast majority of riders out there. In the interest of keeping this review balanced, and since I have been gushing so much about how well this bike works, I need to point out that 29” wheels are still 29” wheels. While BMC did manage to effectively engineer out so many of the geometry quirks that have plagued its predecessors this is still a 29” wheeled bike. If you are a low torque producing rider, getting the big hoops up to speed can still feel like a chore. It still takes more rider input to change direction and at as low as the Trailfox is, at some point, smaller riders may feel it’s just too much wheel. Overall, that sensation of lumbering along, almost like driving a school bus is all but gone. I found my self hopping, sliding, slashing, and roosting every corner on the trail but doing it at speeds that are a bit harder to achieve on smaller wheels.

Wrapping it up

One really cool thing about living in SLC is that we have great trails all around the city with jumps and DH lines right in the middle of them. Sometimes an evening session starts with a lung busting climb, over to a DH run, and then straight into a jump session. Having a ride that can excel at a variety of riding styles is a huge bonus here. It’s not terribly surprising that the Trailfox did just fine on the climbs and I’ve already lauded it’s descending capabilities. Interestingly, despite being a 29’er the Trailfox did not disappoint at the jump lines if you keep your goals within reason. No, I didn’t land any 3’s on it (but it sure was amusing to try) but connecting fast turns and boosting near vertical lips feels totally natural thanks to its short rear and low BB. In fact, it seems that because BMC was able to bring the overall geometry in line with best practices (regardless of wheel size) the Trailfox feels almost totally natural to ride in any setting this side of slope style. There’s no missing the gyroscopic effect of the big wheels on whips and tables but then it also makes for stable flying on bigger hits. From a practical standpoint, this is huge. Most of us simply don’t have the resources to have a garage full of bikes for each discipline. Considering the range of capabilities of the Trailfox, all of the sudden that price tag doesn’t sound so bad after all. When you consider that it might replace two or three of your existing bikes and that there are models starting at $3999 the BMC Trailfox had best be on your list when looking for a new ride in 2014.

Perks –
Dialed, no compromises geometry
High end components throughout
Excellent pedaling performance
Tremendous detail integrated throughout the design
Internal cable routing with full length housing
Accommodates a full size water bottleing
Internal cable routing can be noisy

Quirks –
Lowering the seat post all the way can kink the Reverb line if not trimmed perfectly
The Fox 34 CTD fork could use a little more compression damp
X0 Trail brakes can be tricky to bleed
No carbon wheels until you step up to the $12,000 USD XTR model
They made me give it back!

BMC Trailfox MSRPs –
The Trailfox is offered in 3 frame versions and 5 different build specs. The TF01 gets a full carbon frame, the TF02 gets a carbon front triangle and alloy rear, and the TF03 is offered in a full alloy frame.
TF01 XTR: $11,999 USD
TF01 Trailcrew: $8,999 USD
TF01 frame set: $4,999 USD
TF02 XT: $6,599 USD
TF02 Trailcrew: $5,599 USD
TF03 SLX: $3,999 USD

Learn more at BMC’s website, www.bmc-racing.com