XC speed and automation generously redefined

Our 2023-model-year test bike came with some great features, but the 2024-model-year bike is slated to have some major upgrades like a Fox 34 fork and SRAM Transmission.


BMC (Bicycle Manufacturing Company) is a Swiss company that is well known for their success on both the road cycling and mountain biking world stages. You might remember a certain Tom Pidcock who rode his unmarked Fourstroke to the gold medal in the Tokyo Olympics in 2020. Since then the Swiss engineers have been putting their genius to work to come up with an updated version of that gold-medal-winning bike. Its sole purpose is to go fast and feel the spray of champagne at the end of the day as its rider celebrates another victory.

ON THE RIDER:  Hyperthreads Custom Santa Clarita MTB Team bib and jersey; 100% Norvik sunglasses ($149); Specialized S-Works Recon mountain bike shoe ($425)


BMC uses what they call Premium Carbon to construct the Fourstroke’s frame, but there’s a surprise built into the frame itself. They decided to forgo the use of a traditional seatpost, opting instead to develop a new system called Autodrop technology. This dropper post system with 80mm of drop is built into the frame and uses an air canister located in the downtube of the bike that is charged using a normal floor pump. This canister is activated with a two-stage dropper lever with the second stage releasing an air blast that will drop the post automatically without the rider needing to squat down to drop it with their weight. The saddle height is adjusted by loosening a bolt located about halfway down the seat tube. This frame also fits two bottles on top of the downtube, has easily accessible cable routing, an integrated fork stopper, and a lower link mud flap to protect the frame and Autodrop maintenance access port.

Getting the geometry right is very important to BMC; so important, in fact, that they added the stem, bar, and crank lengths and angles in with the rest of the frame info on their geo chart that shows how they change them according to which bike size you get. Our size large had a relatively slack head angle of 66.5 degrees, a seat angle of 76.7 degrees and a chainstay length of 432mm (17.01 inches).


BMC’s APS (Advanced Pivot System) is employed on this bike with the intention of providing high anti-squat numbers while pedaling and providing a bottomless feel on bigger hits while descending. It has a dual-link design, which is claimed to help achieve a high level of small-bump sensitivity while still providing a great pedaling platform to keep efficiency high. It also takes heavy hits well, resulting in the bike feeling like it has more suspension than it does. Our 2023 test model is identical in suspension design to the 2024 model with the exception of having a different fork.

The 100mm of rear travel felt supportive wherever we rode which helped us push the pace even more.

Our 2023-model-year test bike had a Fox Float 32 Factory Step-Cast fork with a Fit4 damper and a three-position handlebar-mounted remote lockout. The 2024 model has upped the ante to a 100mm-travel Fox Float 34 Factory Step-Cast fork with the same FIT4 damper and three-position handlebar-mounted remote lockout. This fork will take an already capable bike and make it even better at speed with its extra support.

The Fourstroke has 100mm of rear suspension travel as well with a Float DPS Factory shock softening the blows in the rear. The rear shock is also connected to the same DT Swiss three-position handlebar-mounted lockout as the fork.


There are several offerings of the Fourstroke 01 with the automatic dropper, and some Fourstrokes with the same frame design that use an external dropper post instead. Our test bike, the LTD, was the highest spec at $14,300, but you can buy the Fourstroke with the Autodrop for as low as $10,000 or without the Autodrop starting at $4,700. The Fourstroke 01 LTD we tested is the 2023 model year and has a slightly different spec to the 2024 model year, though none of the geometry has changed. The main difference is the use of SRAM’s new slow but smooth-shifting XX SL Eagle Transmission instead of the quick-shifting XX1 AXS Eagle drivetrain present on our test bike.

The only other non-suspension component update is the SRAM Level Ultimate Stealth two-piston brakeset paired with a 180/160mm Centerline rotor combination. These brakes are the direct replacements for the Level Ultimate brakes we had on our test bike, so we expect them to work well for the bike’s designated purpose. Everything else will be the same, including the lightweight and compliant DT Swiss XRC 1200 carbon wheelset wrapped in the fast-rolling and surprisingly grippy set of 29×2.35-inch Vittoria Mezcal tires. The Prologo NDR saddle wasn’t the most comfortable part of the cockpit, but was comfortable enough with the use of a chamois.

A crowded handlebar can be an eyesore, but when the levers are as functional as these, we’ll forgive the mess.

Our favorite part of the cockpit was BMC’s in-house bar and stem combo. The 760mm-wide MFB01 flat carbon bar had great vibration-damping properties and flexed comfortably on descents, keeping our hands from arm pump. We felt very comfortable where the bars and -5-degree rise stem put us, and decided most of us wouldn’t bother to replace them were we to own the bike ourselves.


When we think of cross-ountry race bikes, it’s performance, not comfort that comes to mind, but on the BMC Fourstroke, those two concepts go hand in hand. Wherever we were on the trail, whether standing, sitting or somewhere in between, we found ourselves to be very comfortable. On the performance side, we found the bike to be an excellent, efficient, and capable climber. Our average speed remained high and cadence strong on smooth road climbs where we used the bar-mounted, three-position lockout switch to great effect, mostly in the Climb and Open settings.

The big performance surprise came when climbing steep, technical or tight single-track climbs. We found the bike to be both stable and exceptionally responsive in such sections. The rear-wheel traction was impressive, and we found we could put power down without fear of spinning out or going off the back. Our position on the bike was in perfect balance where we could lift the front end over obstacles or around tight bends without letting off the power. The bike went where we wanted when we wanted it to and was always ready for a quick burst of power, which it then directed firmly to the ground, launching us forward. There was no such thing as a surprise climb while riding the Fourstroke, because it could adapt to any change in the trail instantly and confidently.

The Vittoria Mezcal tires impressed us with the traction they provided whenever we needed it most—even in the loosest corners we faced.


When in an XC race, you need to be able to race the descents as well as the climbs; the Fourstroke did just that. It was light on its feet and willing to change direction at the lightest touch, but was just stable enough that we felt comfortable leaving the brakes alone when it got a little rowdier. We felt support from the suspension without any hand-numbing vibrations or brain-rattling jarring, and found ourselves pumping into the trail more than we normally would to help us keep speed. We also felt comfortable sprinting out of corners, as the Vittoria Mezcal tires easily tracked the ground even on kitty-litter surfaces.

There were a few times we dared to go where no XC race bike should go expecting to find the bike’s hard limits. Again, we were surprised by its reluctance to be overwhelmed as it took gnarly chunk, perilous steeps and loose high-speed corners in perfect stride. Though 80mm of drop doesn’t seem like much by today’s standards, we found ourselves not wanting the saddle any lower in any situation. It was enough drop to allow us to get over the back to navigate steep sections or lift into a manual to get over things, but it remained high enough that we could use it as a leverage point to keep the bike underneath us and provide a bit more stability in harsh conditions.

The Fourstroke could handle everything we threw at it, even a bit of air time.


Take a good long look at this bike and tell us you don’t love how it looks. It was always a conversation starter in the parking lot or on the trail. Aside from the aesthetic pleasure this bike brings, we felt the build specs list BMC brought together to build this bike was excellent. We loved the Fox Factory suspension, the DT Swiss XRC 1200 wheelset and the fast-rolling Vittoria Mezcal tires, which, again, we found surprisingly grippy. There was one thing we noticed that we felt really helped with the vibration damping of the bike and that was the bars. The BMC MFB01 carbon bars had a noticeable amount of flex to them that we wouldn’t trust on anything but an XC race bike. We feel they added a lot to the comfortable ride feel we experienced on this bike and helped with grip lock on longer descents, and we liked the shape.

We can’t go past this section without mentioning the genius of the Autodrop seatpost. It was an incredibly convenient option to have when charging out of the saddle or rolling full speed into a sudden descent where having to squat down to drop the saddle would disrupt our flow. It’s an incredibly efficient and effective system that we have now begun to wish was on all the bikes we have.


When the air canister for the Autodrop seatpost was empty, we had to be careful not to push past the first stage of the lever’s drop or the post would free-float up and down as we sat or stood until we hit the lever again. This isn’t really something we hated, just something to watch out for if you were to find the Autodrop air chamber empty while riding.


It’s clear that this bike was built with one purpose in mind—to win XC races. But, we don’t think it should be limited to that. It’s aggressive, fast and efficient with hardly a missed stroke when it comes to its components spec.

The BMC Fourstroke 01 LTD is for the confident XC rider and racer who knows what they want and who won’t be afraid to push the pace on the whole track, not just the climbs. It’s for the rider who values efficiency and performance over weight being that it’s 24.6 pounds. Though the price is a bit steep, what you’re getting is a complete bike that is ready to race right out of the box. It’s a true, modern XC race bike that is well balanced and fun to ride, so you’ll be smiling all the way to a spot on the podium.




SUSPENSION: 100mm (front & rear)

Price: $13,500
Weight: 24.6 pounds (without pedals)
Sizes: S, M, L (tested), XL
Frame tested: 100mm travel, carbon
Shock: Fox Float DPS Factory, DT Swiss remote lockout
Fork: Fox Float 32 SC Factory, DT Swiss remote lockout
Wheelset: DT Swiss SRC 1200
Tires: Vittoria Mezcal (29×2.35”) front and rear
Seatpost: BMC Autodrop integrated dropper post (80mm travel)
Saddle: Prologo Dimension NDR T4.0
Handlebar: BMC MFB01 Carbon, 760mm
Stem: BMC MSM01
Grips: BMC lock-on grips
Headset: BMC headset with knock-blocker
Brakes: SRAM Level Ultimate
Rotors: 180mm (f), 160mm (r)
Rear derailleur: SRAM XX1 AXS Eagle
Shifters: SRAM AXS Controller
Crankset: SRAM XX1 Eagle carbon
Bottom bracket: PF92 DUB
Cassette: SRAM XX1 XG-1299 Eagle 12-speed, 10-52T
Chain: SRAM XX1 Eagle
Chainrings: SRAM EAGLE 34-tooth


Head tube angle: 66.5°
Effective seat tube angle: 76.7°
Reach: 477mm (18.8″)
Stack: 600mm (23.6″)
Bottom bracket height: 315mm (12.4″)
Chainstay length: 432mm (17.0″)
Wheelbase: 1188mm (46.8″)

You might also like