Review: BMC Trailfox AMP Two

Jan 31, 2019
by Paul Aston  



BMC Bikes are based in Grenchen, Switzerland, surrounded by some of the worlds finest singletrack. They were made famous at the sharp end of the mountain bike market when they launched their 150mm travel, 29" wheeled, carbon Trailfox back in 2013. That bike, along with Specialized's 29" Enduro in 2014, was way ahead of the game, and would still challenge many of the 29" enduro bikes from 2018.

The Trailfox AMP aims to build on the success of the fully human-powered Trailfox with the addition of a Shimano STEPS E8000 motor and integrated battery. We tested the lowest spec AMP Two version that still costs an eyewatering €6999. Money burning a hole in your pocket? The AMP LTD costs a staggering €11999 with all the bells and whistles.


Trailfox AMP Two
Intended use: trail/enduro
Travel: 150mm rear / 150mm front
Wheel size: 27.5+
Frame construction: Carbon front triangle with aluminium rear.
Suspension: Fox Float DPS, Fox 36 Performance
Motor: Shimano STEPS E8000
Battery: Shimano internal 504wh
Sizes: S, M, L,
Weight: 23.06kg (L, tubeless, w/o pedals, actual)
Price: $7499 USD / €6999
More info: bmc-switzerland.com

Contents







BMC TrailFox AMP Two
The massive headtube junction makes the BMC instantly recognizable


Construction, Features and Motor

The main feature of the frame is the carbon front triangle with its giant downtube. The downtube uses a "Twin Hollow-core Tube Design." These are two complete tubes on either side which are connected across the top; the hollow opening on the underside receives Shimano's internal 504wh battery for an integrated system. The head tube junction is also huge and gives the frame distinct look, and possibly storage for a sandwich in the hollow.

The swingarm is aluminum on the AMP Two and connected to the front triangle by BMC's twin-link APS (Advanced Pivot System). BMC claim they have optimized the size and shape of the links to get the perfect characteristics for eMTB riding. More pricey versions of the AMP come with a carbon swingarm which saves nearly 600grams.

The motor is a standard STEPS E8000 unit that has stepped into rival Bosch in terms of MTB sales within two years of being in production. BMC (and others) claim that switching to the internal Shimano battery, they can save a bunch of weight from the frames structure, but a quick drop on the scales show the internal battery weighs 3.21kg against the 2.62kg of the internal type. Oh, there is room for a bottle cage too.


BMC TrailFox AMP Two - Shimano handlebar display
BMC TrailFox AMP Two - Shimano STEPS E800 motor
People worry about the added complexity of eMTBS, but I have not had a single issue with a Shimano motor or battery on any test bike.


Geometry & Sizing

BMC Trailfox AMP Geometry
BMC Trailfox AMP Geometry

BMC Trailfox AMP Geometry

The Trailfox AMP follows on the progressive nature of the acoustic Trailfox. My large sized test rig (unfortunately there is no XL option for taller riders) had a 469mm reach and a 620mm stack height. The head angle is set at 66º, the seat angle at 74º, and there is -17mm of bottom bracket drop. The chainstay is fairly short for an eMTB at 447mm.


Suspension Design

BMC TrailFox AMP Two - BMC s APS Advanced Pivot System

APS stands for Active Pivot System, a design that uses a solid rear triangle connected via two short links to the front end, the upper of which drives the shock.


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Suspension forces with a Cane Creek DB Air Inline

Anti-squat numbers, in this case, are marked with 1, which = 100%

BMC has an interesting take on their suspension layout for this eMTB. They chose to base the anti-squat around 100% throughout the travel, not with pedaling efficiency in mind, but riders' weight balance – an eMTB will accelerate quickly meaning more rearward weight shift of the rider, the antisquat level should keep the rider centralized under power for an easier an more natural feel. The downside of this is increased pedal-kickback (as the bike moves through the travel the chain stretches and rotates the cranks backward) but this seems less of an issue with the heavier weight of an eMTB compared to a human-powered vessel.
The leverage ratio is fairly linear, but drops off at the end of the stroke to match the ramp-up of an air shock.

Pedal kickback is quite high in this case, but seemed to be less of an issue than expected thanks to the added weight of the motor and battery.

The suspension is also designed to be sensitive at the start of the stroke with a high leverage ratio, but progresses linearly through most of the travel, it then reduces at the end of the travel to match the ramp-up of an air shock at the end of the stroke. The anti-rise (no graph provided) is said to be around 80% throughout the travel.




Build

BMC TrailFox AMP Two - WTB supply the saddle which sits on top of a RaceFace Aeffect 150mm dropper
WTB supply the saddle which sits on top of a RaceFace Aeffect 150mm dropper

BMC TrailFox AMP Two - Fox s EBike Optimised 36 uses a solid crown and thicker walled stanchions to take on the extra weight of and eMTB.
Fox's 'EBike Optimised' 36 uses a solid crown and thicker walled stanchions to take on the extra weight of an eMTB.
BMC TrailFox AMP Two - a 2.8 High Roller II takes charge up front.
A 2.8" High Roller II takes charge up front with a low profile Rekon rear. The wheelset is a 35mm 27.5+ H1700 series from DT Swiss

BMC TrailFox AMP Two - Magura MT5 stoppers with 203mm rotors front and rear.
Magura MT5 stoppers with 203mm rotors front and rear.

Starting at the front of the Trailfox AMP, we find a cockpit taken care of by BMC's own brand components. Magura MT5 brakes with 203mm rotors, and Fox's E-Bike Optimized 36 fork is matched to a Float DPX with an EVOL air can. The wheels are taken care of by DT Swiss (who are down the road from BMC) and their Hybrid H1700 wheelset; these wheels feature a thicker wall at the spoke bed, thicker spoke heads and nipple and a steel freehub body. There's a full Shimano XT drivetrain, while RaceFace control the dropper post with a 150mm Aeffect topped with a WTB saddle.

BMC TrailFox AMP Two - 1 4 shot


Specifications

Specifications
Release Date Summer '17
Price $7499
Travel 150/150
Rear Shock Fox Float DPS, Performance, Evol, (150mm)
Fork Fox Float 36, Performance, GRIP, S-Ped, Boost
Cassette Shimano SLX, 11-46T
Crankarms Shimano STEPS
Rear Derailleur Shimano XT
Chain Shimano CN-HG601
Shifter Pods Shimano XT
Handlebar BMC MRB 02, 780mm
Stem BMC AMSM 02
Brakes Magura MT5 (200/200)
Wheelset DT Swiss H1700 Spline 35mm
Tires Maxxis HR II Exo 27,5x2,8 (F), Maxxis Rekon Silkworm 27,5x2,8 (R)
Seat WTB Volt Race
Seatpost RaceFace Aeffect Dropper 150mm

BMC TrailFox AMP Two - Headtube and Fox 36 forks










Test Bike Setup

After the first ride, the front wheel was switched to a 29" setup with some meatier tires (Schwalbe Eddy Current) as I knew it is would only be a short matter of time before the flimsy Maxxis plus-tires were cut by the extra-sharp rocks in Finale Ligure. The added roll-over of the bigger wheel, and increased ground clearance at the bottom bracket is ideal for gnarly climbing, and helped keep the front end up and out of trouble on the beaten shuttle trails and tech lines I was heading for.

The suspension seemed to work best at 20% sag front and 25% rear. I rode the L-sized bike which has a 469mm reach and a 50mm stem.
Paul Aston
Paul Aston
Location: Finale Ligure, Italy
Age: 32
Height: 6'1"
Weight: 75kg
Industry affiliations / sponsors: None
Instagram: @astonator
KM's ridden: 200

BMC TrailFox AMP Two - Climbing


Climbing

The Trailfox AMP started each climb with the face of glee that every eMTB gives you as you cruise away from base nearly effortlessly on the road. The Shimano motor system is quieter than the Bosch, but whirs more than the near-silent Specialized/Brose setup. The bike is super stable under power and maintains its height in the travel. The geometry is commendable when attacking everything up to really steep pitches, where it could falter and start to wheelie and wander off-line. This is not a problem unique to the BMC - overall it is above average, but I feel all of the eMTB's that I've ridden so far rode could have their climbing prowess on steep sections improved massively via the geometry.

It's shorter and steeper than most bikes it was ridden against, which made it slightly more nimble on the climbs to switch direction and pick a clean line. Its only real fault on the way up are its long 170mm crank arms, which took a beating on the knobbly tech in Finale - thankfully, we are seeing more and more eMTB's adopting shorter cranks. Naysayers will claim that I need to improve my pedaling and timing, but this is simply not the answer. My timing is good with a normal bike, but an eMTB will push you to challenge yourself with harder climbs more often, with higher speeds, higher cadences, and the need to keep the cranks rotating for the motor to stay engaged.

BMC TrailFox AMP Two - Downhill riding


Descending

After conquering some gnarly climbs that are impossible on a normal bike, it was time to check the descending capabilities of the Trailfox. The supple suspension at the start of the stroke really helped with smoothing chatter and provided great grip on cambers and flat corners. The progressive nature of the suspension also gave great mid-stroke support, as well as plenty of bottom out resistance from big hits.

Being shorter and steeper than the bikes it was pitched against (Vitus e-Sommet, Specialized Kenevo, Mondraker e-Level) didn't seem to hinder its progress heading down. The slightly shorter reach than I am used to brought back physical and mental recollections of lower backache. But overall, the bike had a great balance and composed character, it is not a super long and slack beast, but the complete system's design, tune, and eMTB weight gave a much more capable ride than the numbers would suggest.

In the corners, the fairly low amount of bottom bracket drop (-17mm) between the axles makes switching between directions quick and easy. It took on most corners superbly, though does lose out on fast and long corners in terms of stability compared to the longer rigs. It also seemed to generate speed well through corners and when pumping terrain, something that some eMTB's lack.

One part of this bikes great handling is down to that massive downtube. Having a huge amount of stiffness here gives a confidence inspiring ride due to its directness and responsiveness between your hands and feet. Yet, the rear triangle is not super stiff which allows the rear wheel to track and trace around corners and through rough sections. Overall the Trailfox is the best all-around eMTB that I've tested to date.





BMC TrailFox AMP Two - Downhill riding



How does it compare?


Compared to any other eMTB I have rode so far, it is bloody expensive. For the best part of €7000, the Trailfox is under-specced compared to its rivals, especially against the direct sellers who have similar components albeit on cheaper frames for half the price. The money here is in the carbon front triangle and Swiss exchange which makes it tough for the brand to compete on price.
Thok Bike Test
Thok's Mig-R is significantly cheaper than the BMC with similar spec, albeit from a direct sales model.


Technical Report

BMC TrailFox AMP Two - Shimano s integrated battery puts the on off button and the charging and locking ports directly in the line of fire.
Shimano's integrated battery puts the on/off button and the charging and locking ports directly in the line of fire.

BMC TrailFox AMP Two - Magura MT5 brakes
Magura MT5 brakes needed a couple of bleeds and a long bedding-in period before they were on point.
BMC TrailFox AMP Two - Shimano XT with an SLX 11-46T cassette.
While Shimano's STEP's motor has been incredibly reliable on every test bikes, the standard derailleurs have not stood up to the e-test.

BMC TrailFox AMP Two - RaceFace Aeffect dropper lever
RaceFace Aeffect dropper lever sits well on crowded eMTB handlebars.

Shimano Integrated Battery: OK, so integrated batteries are more aesthetically pleasing on a perfect side on view of an eMTB, and I understand why people want their bike to look nice. But, compared to Shimano STEPS systems using their standard external battery, the internal one is heavier, bigger (harder to carry a spare in a pack for an epic ride) and places the on/off button, charging port, and key port in the direct firing line of incoming mud. I much prefer to have the standard batteries which are also a little faster and easier to swap out and the important contact points are out of harm's way.

Shimano XT Drivetrain: Another one bites the dust. During a simple pedal up a fire road in a less than taxing situation, I had another rear derailleur and hangar explosion. eMTB motors don't sense the snapping and cut the power, so I ended up with another badly scratched chainstay, destroyed hangar, and derailleur, and spokes, and a long, heavy push to get out of the woods and home. That's the third one this year to go with no warning.

RaceFace Aeffect Dropper This was my first experience with a dropper from RaceFace. The 150mm travel Aeffect worked without issue and the remote lever fits well on the handlebar combined with the Shimano motor undercarriage lever.

Magura MT5 I've had mixed results with Magura brakes recently; most of the time the MT7 with the older style, longer lever had a great feel and modulation, but the same caliper matched with the HC3 lever which is the most expensive, adjustable, and shortest felt like trying to modulate a piece of wood. These MT5's brakes needed an extra bleed from new to stop the bite point changing with heat and took a long time to bed in.



Pros

+ Great all-round ride and handling
+ Stiff carbon mainframe and rocker links
Cons

- Expensive
- Shimano's big and heavy integrated battery


Is this the bike for you?

If the price tag of the bike isn't something that you notice too much before splashing out, then the BMC's biggest negative is already thrown out the window. If you are looking for a great eMTB all-rounder you cannot go wrong with this machine. If you are extra tall, forget it due to the lack of XL size. If you want an eMTB simply to transport you to the top of downhill tracks, then there are better options on the market.


Pinkbike's Take
bigquotesThe BMC Trailfox Amp is a fantastic all-rounder that should suit the needs of the majority of eMTB riders. The price is borderline astronomical for the component package, but this is partly made up for thanks to its great ride feeling. Paul Aston







51 Comments

  • + 43
 i came here for the comments.
  • + 13
 ... which are just copied and pasted from every other Pinkbike e-bike article.
  • + 1
 Aston really is discharging his eBike review obligations. Sadly PB has failed to take heed of the current of emotion around electrical bikes and how polarizing they are. As usual this review left me rather flat.
  • + 42
 Can there be an alternative pinkbike site for ebike stuff?
  • - 23
flag maggotroot (Jan 31, 2019 at 1:43) (Below Threshold)
 also for hardtails, please!
  • + 9
 Ebike should show more relavant data like

horsepower
0-100meter (second)
How long can the battery last

Simple way is how to sell to vin diesel.
  • + 3
 ...just skip it buthead... Smile
  • + 7
 Don't read it if you're not interested, if it was in an " alternative site" would you have read it? Whats the bloody difference?
  • + 0
 @chyu: thought the same, all eBike articles are like: I'm going to review this Motorcycle and pretend the motor is the least important bit.
  • + 20
 This hideous beast for £6555 (according to a quick google search) or 30’680 delicious, crispy, chicken McNuggets? Normally this would be a no brainier in favour of the crispy bois.. however, the fact that I could fit a box of 6 in that lovely gap between the headtube and top/downtube, AND there’s room for a bottle to wash them down with, therefore avoiding indigestion, makes this a VERY tough call indeed..
  • + 3
 Eating ground up birds in 2019 lol
  • + 2
 @colincolin:
Otherwise they die for nothing...
  • + 1
 And you can’t eat a whole one! @cvoc:
  • + 2
 @cvoc: You ever heard of "Supply and Demand" ?
  • + 1
 @NotNamed:
They have to do something with the male ones. The alternative is gassing them right after they are born.
  • + 0
 @cvoc: you didnt understand my point at all sadly.

And theres a technology in the making that can identify the gender of the embryo ... So they wont be even born.
  • + 20
 Is there any point in reviewing how an ebike climbs?
  • + 2
 With exploding drivetrains it makes the climbing bit moot...
  • + 8
 Is there any point in reviewing how a downhill bike descends?
  • + 1
 @hifiandmtb: Then you push 23kg around.... The price you pay for eMoto thrills...
  • + 1
 Is there any point in reviewing how any bike does anything?
  • + 1
 @headshot: have you ever heard of the assisted push mode provided by the E-8000 engine?
  • + 2
 @Euskafreez: does it work when the rear derailleur and chain are mangled?
  • + 1
 Given that the primary reason for having the motor on the bike in the first place is to get to the top of the hill...I'd have to say yes. If an e-mtb can not climb then it truly isn't fit for purpose...
  • + 16
 How did I end up on www.pinkmoped.com?
  • + 15
 I want more articles about the new Guerilla Gravity bike, and less ebikes.
  • + 10
 I have no real problem with ebikes...mainly because at 50, my hill conquering prowess is not what it was and I still want to do this when I'm 80...but 7000 euros?
I'm struggling to see how the addition of essentially only Shimano motor and battery (yes I'm aware it's a bespoke ebikes frame etc etc) can add that much to that inflated pricetag. Surely a human powered Trailfox doesn't cost much over four grand...? So why three grand for a motor and battery I can also find on a commuter ebike that costs lessthan that?
  • + 5
 Dear Pinkbike writers, we are perfectly happy in our limited narrow-minded mindset that difference between bike and motorcycle is in engine and we don't want to deal with anything engine like on this site. Put all e-stuff on some other site and let people have a choice to either see that or not.
Analogy:
You have a mtb-veggie restaurant and very happy mtb-vegetarians inside that worship you and your restaurant and your mindset. Even e-omnivores are welcome in here (of course they will not get e-meat) .
But don't make a mistake and start serving meat wrapped up in green salad leaf as "this is still veggie" because you will loose your most important and fanatic customers and become just one of zillion simmilar restaurants that want to serve anything and everything to anyone because there are already too many restaurants like this.
Stay mtb-veggie and preserve the difference.
  • + 1
 It's just a different pont of view, as many people (me included) see that analogy in a different way :
MTB = food of all kind
e-MTB = sub-category food, like veggie food is a sub-category of food of all kind
So e-mtb is like the veggie menu of the mtb restaurant.
Also just like there are more and more veggie people, there are more and more e-mtb.
  • + 0
 @Will-narayan: @Will-narayan: to be more accurate, e-mtb would be the shark fin soup menu of the restaurant. Or any other profoundly environmental unfriendly type of food.
  • + 4
 To all those people with their all so "original" anti Ebike comments,there was a poll a long time ago where we could choose if we wanted this kind of content or no.I wonder how you all missed this,but still manage to click on every Ebike article.The fact we have these reviews means you were clearly in the minority,live with it.
Maybe start you're own website instead of posting the same shit over and over again.The upvotes you get are just from the other losers from the poll,fact!
Vote away mitches!
  • + 4
 BMC is a brand mostly associated with roadies and spandex anyway. Add a motor in that mix and you've got a full day of Pinkbike rage !
  • + 6
 Fugly
  • + 5
 Motorbike.
  • - 1
 Good to see Pinkbike post a review of an ebike, seen a few posts on the instagram feed but nothing on the actual page. I just assumed they were too scared to present this kind of content to the narrow minded yet vocal nay sayers who clog up the comments section all too frequently. I can't blame them I suppose, all the other North American sites are pretending that ebikes aren't in the marketplace or as popular as they are, perhaps they justify to themselves that it's just a UK/European thing?

Or is it that the USA audience in particular blames the potential popularity of ebikes will endanger their access rights to trails even further, all that view does is reinforce a negative view in people who already view our sport in a negative way, we all know MTBing doesn't damage the landscape but convincing others in the US seems all but impossible, so words like 'motor' can be emotive and in the case of 'pedal assist' misleading, these bikes used in the right way with the right legislation and software from the manufacturers can be restricted to 16-20mph, after that they're the same as any other bike, similar tyre compound, just heavier. Before we go down the route of greater damage caused by ebikes, how many regular riders, dig up landscape for their own ends, drag rear wheels through loamy corners etc?

For the record I have an ebike, a levo, but I so have an enduro, a 29er, I consider myself very lucky, so I'm the worst kind of guy in some peoples eyes, all ebikes do for me, is get me out on the trails more often and for longer, I don't prefer one bike over the other.

On the BMC itself...too expensive.
  • + 2
 And yet, after all this time,considering all these options , calculating all facts...still NO.
  • + 3
 No ebikes on Pinkbike please
  • + 2
 Con - it's a motorcycle. BOOOOO...... I guess it will be just a matter of time when we will see skidoo and jetski test here
  • + 2
 Why bother with a ‘climbing review?’. Surely you push the throttle and it goes up?
  • + 3
 kill it with fire!! Wink
  • + 1
 Please make a selection option so NAmerican readers can have emtb reviews/news in their daily feed. TY
  • + 1
 Your drivetrain must be crazy huge if it incorporates a hangar...

Must be hard to get through even roomy trails Wink
  • + 1
 doesn't look like a session
  • + 1
 Thok it to me rather!
  • + 1
 Moby Dick¿
  • + 0
 你好bollocks
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