BMC lately launched a completely new household of Fourstroke XC full suspension bikes, with the headlining Fourstroke 01, the usual Fourstroke, and the “downcountry” Fourstroke LT.
Shortly after, they added the Fourstroke AMP LT, an ultralight motor-assisted eMTB model of the LT. I rode all of them on the launch in France, then raced the 01 within the Roc d’Azur Masters Race for good measure. It was a stable 4 days of driving, offering a stellar technique to expertise the bikes and see simply what makes each tick.
Listed here are my journey critiques for every mannequin, beginning with a fast recap of the important thing variations between them…
BMC Fourstroke Household
The BMC Fourstroke 01 is their top-level race bike and options the superb new Autodrop seatpost. It has 100mm journey entrance and rear utilizing their very environment friendly APS linkage design. Up to date geometry give it trail-worthy dealing with acceptable for at present’s aggressive World Cup XCO programs, and Titouan Carod has already ridden his new Fourstroke 01 to a win.
The Autodrop seatpost makes use of a dual-position lever, appearing like a daily dropper seatpost at first. However with a deeper push of the lever, it’ll drop on it’s personal, saving valuable vitality because you don’t should squat to drop it.
There’s additionally a typical Fourstroke mannequin that makes use of barely decrease grade carbon fiber and a typical dropper seatpost, however is in any other case the identical. Examine the full particulars of those bikes right here.
The Fourstroke LT is just an extended journey model of the bottom mannequin, getting 120mm journey entrance and rear. Geometry is similar, it simply sits a little bit taller, giving it some snappy downcountry vibes. All fashions max out at 29×2.4″ tires. Full tech particulars on this mannequin right here.
The Fourstroke AMP LT hides the TQ HPR50 drive system in a slim, light-weight body for a whole bike underneath 35lbs in prime trim. It’s fast, quiet, and performs almost identically to the analog model. Full tech particulars on the AMP LT right here.
2023 BMC Fourstroke 01 assessment
We began the week off on the French mountain bike staff’s semi-private testing grounds. The course is frequently up to date so as to add options mimicking upcoming Olympic XC programs, giving them an edge in coaching.
The circuit is difficult, technical, with a number of energy climbs, difficult corners, and surprisingly massive drops. Lots of the drops and drop-ins are blind, too, very similar to the Olympic programs.
An important XC bike wants to have the ability to dash effectively, and the 01 does. All 01 fashions include distant lockouts, and the Rockshox geared up bikes use their TwistLoc distant, which is unquestionably probably the most ergonomically and aesthetically pleasing choice.
As standard, I don’t usually use a lockout, however the twist-to-lock-and-unlock ease of this distant had me utilizing it throughout the precise race far more than I assumed I’d. There are a whole lot of hearth roads and clean singletrack sections, and it made a noticeable distinction within the bike’s persona…it felt extra environment friendly.
That stated, BMC’s APS twin linkage suspension is wickedly environment friendly and grabs the bottom underneath energy. Due to a little bit of anti-squat, it’s a motorbike that I may grind up the climbs by way of unfastened or technical terrain and the rear tire simply wished to eat the bottom, but the suspension stored working over rocks, ruts, no matter.
BMC recommends a beneficiant 30% sag, and the BB is decrease than ever. That combo did yield extra pedal strikes than regular, however the dealing with and suspension efficiency are value it.
There’s no denying XC bikes have develop into extremely succesful, however the BMC appeared even a step forward of that sport. I drove it exhausting into huge man-made rock gardens such as you see above, and flew blind into rugged descents on the Roc d’Azur course that had many a competitor strolling off to the aspect.
The Fourstroke 01 took all of it in stride, protecting me crusing easily by way of all of it. The slack 66.5º head angle actually helped maintain me over the bike (and never over the bars) on among the steeper stuff, however the bike nonetheless felt XC fast when it wanted to be.
At first look, a whole lot of the options on the French staff’s check course would have me wanting a 120/130 path bike. However the Fourstroke confirmed its mettle and stunned me with its functionality. Actually, it’s a rattling spectacular bike in each approach.
I admire that BMC let me cling round to take part within the Roc. Driving a motorbike on a media journey is one factor, however placing it by way of it’s paces in it’s supreme setting is all the time a greater check.
42km in 2:34:52 was a stable effort for me, netting me 199th out of 745 entrants. Zero mechanicals and nil wrecks.
As a lot because the bike is a standout by itself, the Autodrop seatpost is totally phenomenal. It positively takes a pair rides to do not forget that it’s there, however the behavior types rapidly and the advantages are enormous. I can’t overstate how superior it’s to pre-emptively drop the saddle with out having to alter pedaling cadence or place on the bike.
It was completely an enormous engineering problem for BMC, which they pulled off whereas protecting the bike very light-weight…severe kudos there. The one draw back is the price, these bikes are costly due to all that R&D and tech that needed to be developed from the bottom up. However that’s BMC…they’re not afraid of constructing an costly bike if it means they will make the very best bike. And that is positively among the finest bikes I’ve ridden.
FWIW, I rode the Fourstroke 01 Three, the bottom spec within the 01 lineup, and if it have been my cash, that is the one I’d get. Stable spec, and the alloy wheels are the one factor I’d need to improve.
Additionally, two bottle cages on the downtube? Superior.
2023 BMC Fourstroke LT assessment
Take all the pieces that’s good concerning the 100mm Fourstroke and provides it extra journey and you’ve got the Fourstroke LT.
It loses the 01’s Autodrop put up (and $1,000 off its price ticket), however is in any other case the identical precise bike, geometry and all.
Which meant I may dash alongside the flat stuff and rip by way of singletrack simply as rapidly…
…and energy up the unfastened, steep, or loose-and-steep climbs simply as effectively.
However the added journey introduced extra functionality on steeper, rougher descents. The LT comes with 2.4″ tires (versus 2.35″ on the 100mm fashions), so there’s a bit extra cushion and traction there, too.
Consider the Fourstroke LT as the marginally extra playful sibling that’s equally expert, only a bit extra comfy on longer rides and much more succesful on technical terrain. BMC errs on the aspect of slacker, so the identical 66.5º head angle works simply as nicely right here with the 120mm journey, and it’s on par even with many opponents’ bikes utilizing 130mm forks.
BMC is aiming it on the marathon and stage-race crowd, and except you’ve been personally invited to gun for the highest spots at such occasions, the additional journey might be well worth the slight weight penalty (in any case, it’s solely the fork and tires which can be actually any greater).
I’d wish to see BMC promoting the higher linkage individually so we may convert between 100mm and 120mm rear journey, then simply change the fork…or not, making a 120/100 ripper.
BMC Fourstroke AMP LT assessment
At simply 15.9kg (~35lbs), the BMC Fourstroke AMP LT is comically gentle for an e-bike. Not simply an eMTB, however any e-bike.
They do that by utilizing the TQ HPR50 system, a 50Nm motor that, all in with battery, cables, distant, and show, barely provides 9lbs (3.9kg) to the bike. And BMC retains the identical spec as on the common LT; nothing right here is beefed up for eMTB use. The bike is so gentle it doesn’t should be.
The good factor about this, aside from it being actually gentle, which is superior by itself, is that it seems to be, rides, and appears like a daily bike.
The truth is, I felt extra “in” the bike on the AMP LT, versus “on” the bike with the common LT. Which is smart – the AMP LT has a 37mm decrease standover peak and 2mm decrease BB drop. Regardless of having a barely taller stack peak, I felt decrease on the AMP than on the usual LT.
Each felt good and dealt with positive, however driving the LT after being on the AMP the day prior felt a little bit tall at first. Which is to say, the AMP LT actually does really feel low and steady and quick, similar to the others.
Besides that it makes climbs like this enjoyable. The TQ system delivers simply sufficient energy to peacefully nudge you up techy climbs with out the unsettling burst that stronger motors can ship.
Climbs like these (any climb, actually) are nonetheless work, and 50Nm of torque is sufficient to make them vary from enjoyable to tolerable (versus powerful to “f*%ok it, I’m strolling”).
It’s sufficient increase to energy by way of these undulating sections that may actually tax your quads, alternating between standing and sitting each couple seconds. Energy supply remained clean and predictable, with a wonderfully ramped onset of energy at first.
The pure energy supply is very useful on steep, punchy sections like that that inevitably sit straight round an excellent tight change again, mocking me. And the Fourstroke’s sturdy XC genes exhibit their climbing prowess, combining with the motor’s help to make me feel and look like a rockstar.
Additionally value noting is it’s potential to take care of traction on unfastened climbs. Those self same XC genes mix with just-enough energy output to maintain the bike pushing ahead with out spinning out.
The TQ motor’s jumps between Low, Medium, and Excessive modes are clean and delicate. They’re noticeable, as in, there’s a transparent distinction between them that’s particularly noticeable on climbs, however they’re not so dramatic that they threw off my rhythm. Which, on a unfastened climb like this, is important to sustaining ahead momentum and traction.
The Fourstroke AMP LT begs the identical query as different bikes utilizing this mid-powered motor… why? Why not go greater?
The straightforward reply right here is weight. The AMP LT would virtually really feel similar to a daily bike if I ran out the battery. I may simply pedal this residence underneath my very own energy. However, with an out there Vary Extender battery pack boosting complete out there vitality to 520Wh, it’s unlikely I’d should.
And the low weight makes the dealing with really feel acquainted, too. Plus, it’s quiet, so it appears like, nicely, nothing. So I can hear nature. Or simply hear the bike working, my coronary heart pounding, or the dialog with pals as we roll up hearth roads. Nothing about this bike is competing with my ambiance.
Large, highly effective e-mountain bikes have their place; they’re an absolute blast at bike parks and in massive mountains. However gentle bikes are enjoyable, too, and most of my driving is on trails the place something greater, longer, or extra highly effective than this could be overkill. Horses for programs… in order for you a really quick feeling, succesful bike that’s surprisingly gentle for what it could possibly do, the BMC Fourstroke AMP LT is value a glance.