BMC rolled out their 2018 trailbike range with two lightweight, carbon-framed rippers. The first was the 100-millimeter-travel Agonist, which is a thinly disguised World Cup 29er cross-country race bike endowed with just enough "long, low and slack" to cross over into the trailbike realm. But, the star of the show was the 120-millimeter-travel Speedfox 01 that debuts BMC's innovative "Trailsync" remote system. Trailsync is one of those brilliant, "why didn't someone think of this a long time ago" concepts that simplifies the riding experience when simplification is needed most - high speeds and varied terrain. When the post is up, the shock is firm. Drop it and the post switches the shock to "Rock and Roll." It's a cable-operated mechanism tucked inside the frame and controlled by a single remote dropper lever.Meet the Speedfox 01
Construction and Features
BMC sent PB a Speedfox 01 for a full review a while back and It has been an impressive ride so far. They tell us that it was specifically designed to slot into the light weight (26 pounds, medium size) cross-country trailbike segment, but not to be fooled, its geometry has been tweaked in the proper directions to provide an ample skillset for descending and technical riding. To fit the widest range of riders, BMC offers the Speedfox chassis with 27.5-inch wheels in the small and medium sizes and 29-inch wheels in medium, large and extra large sizes.
The medium-sized 29er we are riding has a roomy, 24-inch (611mm) top tube, with a 430 millimeter reach. The steering is kept light and responsive with a 68.25-degree steering angle and a 51-millimeter-offset RockShox Pike fork. With the exception of its Fox Float Evol remote shock and 30-millimeter-wide DT Swiss XM 1501 wheelset, BMC's top-tier Speedfox is decked out in SRAM from tip to toe - Eagle XO1 drivetrain, Guide Ultimate brakes, and that 120-millimeter Pike RCT3 fork.
With its internal cable routing and integrated dropper post, the new Speedfox looks brilliantly simple in profile, which further showcases its designers' goal - to integrate every feature of the Speedfox to provide a seamless trail experience. BMC offers the Speedfox at seven different price points, starting at $7499 USD for the '01 model showcased here, to $2199 for the most affordable '03 bike.
The heart of the Speedfox chassis is a 120-millimeter-travel, four-bar, dual-link rear suspension - a system that BMC has used since day one. The lower link is protected by an articulating rubber flap to keep crud from collecting on the frame's most highly-stressed pivots. The vertically-mounted Fox Evol air-shock is driven by a sturdy aluminum rocker link, which is printed with a very useful sag indicator on the right-hand side. The shock is inverted to position its cable-remote compression mechanism in a hatch formed into the downtube. The hatch is large enough to give mechanics ample access to change or adjust the remote cable and for riders to easily tune the rebound dial.
On the subject of internal cable routing (and there are many inside the Speedfox), BMC molds separate tubes inside the carbon chassis so there will be no issues threading new housings through the chassis. Further assisting the process, BMC designers incorporate two plastic access hatches, one below the top tube at the seat tube junction and another where the old-fashioned front derailleurs used to mount. More about those later.
Stepping back, the Speedfox frame has been designed to maximize stand-over clearance and thus, gives shorter-legged riders a chance to size up, should they need more reach. The vertically-positioned shock leaves plenty of room for a large-sized water bottle on the downtube, and heavy rubber protectors beneath the downtube and on the drive-side chainstay protect the carbon chassis and ensure a silent-running bike. To further protect the Speedfox, BMC adds a chainguide plate on the inside of the chainring.
(Clockwise)The sag indicator on the right rocker arm. Rubber protection for the carbon downtube. Access door to service the connector cable to the shock, and the chainguide plate.
Geometry is very Swiss, with a conservative, 73.25-degree seat tube angle to enhance long, seated climbs, and a 13-inch-high bottom bracket (37mm drop) to keep the pedals just high enough to prevent boulder bongo. As mentioned, the top tubes are stretched to modern trail specification and its 68-ish degree head tube angle, acting upon its 29-inch wheels, provides enough stability for technical trails, while keeping the steering light and responsive for tight corners and precision line selections. Interestingly, the Speedfox 29er has 17.5-inch chainstays (445mm), which seem long by present fashion. Summed up, the Speedfox's geometry is a balance between established cross-country numbers in the pedaling department, and stabilizing factors that have evolved from all-mountain and enduro.
BMC's Trailsync system uses a single remote lever to operate the Seedfox's integrated dropper post and Fox shock's compression mechanism.
BMC says that Trailsync was invented by a BMC employee who engineered the system for his personal bike. The design team was skeptical at first, but after a number of lunch rides, they quickly realized the value of his invention and went to work to develop a system that could be viable for production. The SpeedFox was chosen for the Trailsync system because BMC test riders believe that the instant integration between the dropper and the shock's "trail" and "open" settings would be more useful for a fast-paced cross-country trail rider who is constantly dealing with grade reversals - as compared to enduro-style riding, which is biased towards extended descents where cyclists, regardless of dropper height, may not want to sacrifice ride quality for enhanced pedaling efficiency. BMC was correct in that assumption, and designed accordingly.
Open or Trail: Integrated dropper post:
The first thing you may notice, is that the Speedfox's seatpost is integrated with the frame. It is shipped extra long and is cut to length to suit the customer's optimum saddle height. The seat clamp head is a separate piece that slides over the upper end of the post and offers 25 millimeters of adjustment. BMC says that the integrated post is necessary to locate the cable-operated internals where they could be easily accessed through ports strategically located in the frame. Should you sell the frame and a longer post is needed, the internals are easy to replace.Three positions:
BMC's dropper has only a 100 millimeter stroke and its mechanical internals operate much the same as a Fox D.O.S.S
. does, with hard, pre-selected stops and a fast-returning pneumatic spring. The BMC post has a single lever that can be pushed in any direction to actuate it, but that means you'll need to feel for the three drop positions that, fortunately, snap into place with a resounding "click." In case you were wondering, you can go all the way down the full 100 millimeters, or stop the post at 20 millimeters, or at 80 millimeters down (approximate measurements). The options are there if you prefer them, but the post operates seamlessly when you ask it for full travel.
BMC wisely chose what most shock makers call their "trail" damping position as the default when the post is at full extension. The firm, damping action of the Fox Evol shock provides more than enough pedaling support for aggressive, out-of-the-saddle efforts, while ensuring that there will always be enough rear suspension action to cover the need to high-post an unexpected rock garden or rooted descent. The probability of that occurrence, however, is minimized by the nearly instant response of the Trailsync system.Shock Options:
The way Trailsync operates is the remote lever operates only the dropper seatpost. A separate cable and housing links the shock's remote to the post, The post drives the shock to ensure that the shock's remote is always synchronized with the post's position. If you want to use a different damper, you'll probably have to sacrifice the Trailsync function, but the Speedfox's dropper seatpost will still function perfectly.Riding the Speedfox 01
Having the opportunity to ride the Speedfox on home trails meant I could make an apples to apples comparison with a number of test bikes I have done laps with on the same features. The suspension sweet spot seemed to be 25-percent sag on the shock and 20-percent up front, with three clicks of low-speed compression on the Pike fork and just enough low-speed rebound to silence the chatter.
My first concern was how I was going to deal with Trailsync's minimal 100-millimeter-stroke dropper post down the steeps. The answer was, "not too bad." I would have been more comfortable with a full-stroke dropper down some of the rock rolls, for sure, but once I learned that I could trust the Speedfox on the downs, I found few moments that gave me pause. The bike's geometry favored a central position over the bike in technical sections and its slack-ish seat tube angle kept the saddle out of the way. So far, so good.
Okay then, what about that Trailsync action? Well, to begin with, 120 millimeters is hardly enough suspension travel to argue about these days. With 37 millimeters of bottom bracket drop and 29-inch wheels, the Speedfox can roll up and over anything you'd need 120 millimeters to smooth over anyway, so when the post is high and the shock is in trail mode, the BMC's suspension is firmed up, waiting to deal with larger impacts. The Speedfox lives up to its name - it absolutely rips on pedally trails and it wholeheartedly encourages its pilot to jump out of the saddle for punchy climbs. In short, it carries a lot a speed - everywhere.
Trailsync is like a gateway drug. It's so easy to get used to and in only one ride, you'll want more. Its action is instant, and the loud "thwack" sounds it makes at full down and topped-out modes leave no question that the saddle and rear suspension is exactly where it needs to be. I began to use the dropper lever almost as much as my shift lever.
Drop the saddle for a descent and, with the rear of the bike unweighted, the shock transitions to a seamless feel in the open position. It doesn't take much to bottom out the fork and shock when descending at full gas, but that is expected when you are riding a short-travel machine. The more important attribute of a good cross-country trailbike is when
you exceed the suspension's capability, that the bike remains calm and in control. In this case, the big-wheeled BMC makes a good argument for bashing around on a 120-millimeter chassis. It is refreshingly quick under power and (like most short-travel bikes) it corners and descends predictably at the same ride-height. And, while there is no questioning when it is being ridden beyond its comfort zone, it always gives you a lot of room for error. Quite fun. And, the rest of the bike?
So far, I have found little, if anything, to complain about. The Speedfox 01 has a sensibly appointed cockpit: its drivetrain is SRAM's best-value XO1 Eagle ensemble, and its 30-millimeter-wide DT Swiss wheels and Maxxis ForeKaster tires are exactly what a capable 29er speedster needs to do its job well. The only parts I plan on changing are its horrific grips - without gloves, I think they would draw blood.First Impressions: