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(The Gear Loop) - Rewind the clock a couple of decades and times were simpler for the hardy mountain biker. Most rode hardtail machines, while those at the bleeding-edge of technology perhaps benefited from some front fork suspension to soak up the lumps and bumps.

Today, there is a bike for pretty much every genre and sub-genre you can think of. Downhill, single track, downcountry, enduro, jump bikes… the list is almost endless. But you can’t say that rider’s needs aren’t catered for.

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The XC (cross country) scene, in which the latest BMC Fourstroke 01 Two neatly fits, is all about bashing your way around a dedicated course as hard and fast as you can, leading to some of the most exciting bike racing you can think of.

These sleek, low and pointy racers now feature both front and rear suspension, as well as things like dropper posts and powerful disc brakes, which allow riders to take on and dominate far more technical courses than ever before.

The Gear LoopBMC Fourstroke 01 Two review photo 8

For more recreational riders, the humble XC bike can prove a versatile and extremely rapid way to cover single track and other light mountain biking duties in the fastest and most efficient way possible. But it comes at a price.

So, while the BMC Fourstroke 01 Two might have been designed with racing in mind, we’ve been testing it on some of our favourite singletrack to see how well it covers ground.

The Gear LoopBMC Fourstroke 01 Two review photo 11
  • The BMC Fourstroke 01 Two costs $9499 USD/€8999 and is available via local BMC dealers, which can be found here.
Our quick take

Potentially overkill for most folks' general gravel needs, the BMC Fourstroke 01 Two has been honed for fast XC racing and that is where it will thrive. But that’s not to say it doesn’t make a mean and versatile way to tackle your favourite trails. Granted, there are beefier options out there for the extreme stuff, but they won’t be as rapid as this. Although they might be cheaper. 

BMC Fourstroke 01 Two review: this XC race bike makes for a rapid ride to cover technical ground

BMC Fourstroke 01 Two

4.5 stars - The Gear Loop recommended
For
  • Razor sharp handling
  • Smooth and reliable shifting
  • Auto dropper post is clever
Against
  • Bottom bracket feels low
  • Too niche a bike for some

In the Loop

Everything you need to know about the BMC Fourstroke 01 Two in short:

  • SRAM GX Eagle AXS Drivetrain
  • RockShox SID SL Select+ Fork
  • RockShox SIDLuxe Select+ Shock
  • TwistLoc Lockout function on rear shock
  • DT Swiss XR 1700 Wheelset, 25mm Inner Width
  • Auto drop dropper post
  • Frame optimised to fit two water bottles
  • Internal cable routing
  • SRAM Level TLM brakes

Design and features

The BMC Fourstroke 01 Two is really designed for elite level cross country racers, taking everything the marque has learned from its illustrious competitive career and distilling it into a machine that will perform at the sharp end of pro racing.

The Gear LoopBMC Fourstroke 01 Two review photo 2

To get all scientific, and to prove the lengths BMC has gone to here, it features a 66.5-degree head angle and elongated front end, while 429mm short chain stays ensure power is delivered without traction slipping.

An extra low bottom bracket and super steep seat angle finesse the weight distribution and improve handling when the trails get tough. Wide, clean bars also mean there is a distinct lack of clutter to get in the way when things get hectic.

The Gear LoopBMC Fourstroke 01 Two review photo 19

This is aided by the brilliant SRAM GX Eagle AXS Drivetrain, which uses electronic shifting for a fast and reliable experience. This leaves the left (or right, depending on your preference) side of the bars free for a thumb shift that operates the dropper post and a twist grip function that manually locks out the rear shock.

It may seem extreme, but this allows the rider to either have the seat drop away when descending the really technical stuff (and leaping through the air), or locking out the rear suspension to maximise power transfer - and therefore speed - over flatter sections.

The Gear LoopBMC Fourstroke 01 Two review photo 3

Efficient rolling speed is also improved via a set of DT Swiss XR 1700 wheels shod in grippy Vittoria Mezcal tyres. The max tyre clearance is 62mm and BMC pushes this with the 60mm tyres that come as standard.

Tech and auto dropper post

A dropper post is nothing new in the world of downhill and enduro riding, but they are also becoming ubiquitous in the XC community. They provide a quick way of improving handling on steep descents, as they allow the rider to shift bodyweight directly over the real wheel for added traction.

The Gear LoopBMC Fourstroke 01 Two review photo 4

That said, most dropper systems require the user to dump some body weight on top of the saddle to initiate the dropping process. In the quest for maximum pedal efficiency, BMC has done away with this.

Its unique auto dropper post system uses air that’s stored inside a lightweight carbon tank that’s neatly integrated into the downtube. It offers around 100 actuations before it requires topping up, but this is as simple as pumping it with any Schrader valve compatible pump.

The Gear LoopBMC Fourstroke 01 Two review photo 10

To activate the post, it’s as simple as fully depressing the thumb lever on the bars, which sees it rapidly drop out of the way. A gentle half push of the same lever sees it spring back to its original position. Clever stuff.

Riders also have the option of locking out the rear shock with a TwistLoc Lockout function. Similar to twist-shift gearing, the grip can be twisted towards the rider to clock things out and twisted away to release.

The Gear LoopBMC Fourstroke 01 Two review photo 5

Performance

It becomes clear from the first few rides aboard the BMC Fourstroke 01 Two that this is a fast and purposeful machine to tackle a variety of different surfaces. The bike feels planted and easy to thread through complex and technical single track, yet the suspension set up means it doesn’t bottom out or come unstuck when flying over jumps and drops.

Anyone not used to XC bikes will perhaps find the riding position a little odd, as it is really set up for maximum power transfer through the pedals and a pursuit of speed. However, this makes it a great bike for smashing routes fast.

The Gear LoopBMC Fourstroke 01 Two review photo 15

Activate the auto dropper post and it rapidly transforms into something that’s able to tackle more technical terrain. Shifting the body weight over the back wheel means it can be thrown through tight berms and complex corners with ease.

The lower bottom bracket is interesting, as it requires a fair amount of concentration to avoid pedal strike when blasting through tight corners. Arguably something that won’t blight seasoned XC riders, but we can’t claim to be such a thing.

The Gear LoopBMC Fourstroke 01 Two review photo 7

In fact, we tested the bike fully both decked out in Lycra and clipless gravel shoes, as well as in more casual MTB gear with flat pedals, and found the BMC Fourstroke 01 Two to be equally enjoyable to ride in both cases.

A lot of our local routes feature gravel paths, fire tracks and sections of road to reach the fun stuff and the Fourstroke was at home on all of these. The lock-out rear suspension meant it was possible to dispatch of boring tarmac sections quickly, while auto dropper post and general tough demeanour meant it was equally happy to bash the trails. There's also room for two bottles on the frame, making it great for longer rides. Although strapping luggage to it might be a niche too far.

To recap

Even in the hands of mere cycling mortals (that’s us, by the way), the BMC Fourstroke 01 Two proved a flattering machine that made mincemeat out of technical single track and fun gravel trails. It is fast and comfortable to ride, meaning it’s something you could potentially reach for time and time again. That said, there are plenty of other XC bikes that do a similar job for a fraction of the price. BMC’s race-winning tech doesn’t come cheap, but it could offer the edge for those taking their racing seriously.

Writing by Leon Poultney.