Joining the new crop of shred-worthy XC race bikes, BMC has just announced their all new Fourstroke 01. Crammed full of all the latest advances that are meant to give their racers an edge, the Fourstroke 01 also has something most of its competitors don’t – an integrated dropper seat post.

All new BMC Fourstroke 01 gets RAD with integrated 80mm XC dropper post

However, you’d probably never realize it just by looking at it. Since it’s integrated, the post maintains a continuous profile that looks completely stealth.

All new BMC Fourstroke 01 gets RAD with integrated 80mm XC dropper post All new BMC Fourstroke 01 gets RAD with integrated 80mm XC dropper post

It’s only when you realize that the post is actually oval instead of round that you start to realize it’s something special. Called RAD or Race Application Dropper, BMC claims it is the world’s first integrated XC dropper post – it’s definitely not the first integrated dropper so their claim all depends on what you consider XC. Regardless, it’s a very interesting feature – especially when you consider that it wasn’t that long ago that XC racers didn’t want anything to do with a dropper.

Perhaps the decreased weight of the RAD system had something to do with that, however. Thanks to the oval shape which allows for a 30% stronger (claimed) structure with less weight, the overall weight of the dropper is just 345g. To keep things simple, the post is completely mechanical and uses very low pressure (29 psi) which should improve the seal’s durability in the long run.

All new BMC Fourstroke 01 gets RAD with integrated 80mm XC dropper post

Limited to two positions (up or down), the post offers 80mm of travel. However, it does limit you to a 90mm saddle height range for any given size which can be adjusted like a conventional post and doesn’t require any cutting. That height range may be a bit of an issue depending on your fit though – I typically ride a medium with a 690mm saddle height. On this bike, the shortest saddle height for the medium is apparently 700mm. The given ranges are 655-745mm for the Small, 700-790mm for the medium, 740-830mm for the Large, and 770-860mm for the Extra Large.

To adjust the post, there is a low clamping mechanism just above the chain guide on the seat tube – this is apparently another benefit of the design since the clamping mechanism is at the bottom of the post, the clamping forces won’t affect the dropper’s performance as often happens with traditional designs.

All new BMC Fourstroke 01 gets RAD with integrated 80mm XC dropper postAll new BMC Fourstroke 01 gets RAD with integrated 80mm XC dropper postIn order to maximize every gram, the new frame includes fewer parts which should also improve durability. Now you’ll find an integrated headset, a new carbon upper link, optimized suspension hardware, a new super light thru axle at the rear, and a one piece rear triangle for a frame weight of 2180g with shock. Add in the RAD seatpost and hardware and you’re looking at 2525g, with complete bike weights as low as 10kg (22lbs).

All new BMC Fourstroke 01 gets RAD with integrated 80mm XC dropper post

 

Also, thanks to carbon work from BMC’s IMPEC lab, the frame offers 23% more torsional stiffness and 15% more stiffness at the bottom bracket. Combine that with their APS suspension system which has been tuned for XC racing with 100mm of travel, and the Fourstroke should be a rocket ship. The APS system utilizes a metric, trunnion mounted shock.

All new BMC Fourstroke 01 gets RAD with integrated 80mm XC dropper post All new BMC Fourstroke 01 gets RAD with integrated 80mm XC dropper post

Elsewhere, you’ll find internal cable routing with a replaceable cable port cover behind the head tube that also doubles as a lightweight fork bumper. The housing has a full guide for the rear derailleur and brake through the frame to the rear swing arm, and there’s a large access window underneath the shock.

All new BMC Fourstroke 01 gets RAD with integrated 80mm XC dropper post

Designed for 1x only, the frame includes an integrated chainguide, and the frame includes a chainstay protector, co-molded stainless chain suck plate, and a lower link mud flap. The rear has also been reworked to allow for larger tires, now clearing up to 29 x 58mm (2.28″) rubber.

Other frame details include a PF92 bottom bracket, Boost 148mm spacing, a 44mm offset fork, post mount brakes, and a 38t maximum chainring.

All new BMC Fourstroke 01 gets RAD with integrated 80mm XC dropper post

Utilizing BMC’s Big Wheel Concept Race geometry, the Fourstroke moves to more progressive XC geo for more aggressive riding. Combined with a longer front end, you’ll now find a 67.5° head tube angle and a steep 75.5° seat tube angle with 429mm chainstays.

All new BMC Fourstroke 01 gets RAD with integrated 80mm XC dropper post All new BMC Fourstroke 01 gets RAD with integrated 80mm XC dropper post All new BMC Fourstroke 01 gets RAD with integrated 80mm XC dropper post

There are three different models to choose from, the Fourstroke 01 One, 01 Two, and 01 Three, or the 01 frameset. We’ll update when we get pricing.

bmc-switzerland.com

 

17 COMMENTS

  1. Nice with the short chanstays, by why so slack? 67.5 deg seems like a big jump from the 70 deg on the previous FS. In my opinion an XC bike still needs to be nimble in slow and tight corners. Will the shorter chainstays really compensate enough for the slacker front in those turns?

    The integrated post is interesting. But it seems like I cannot use the bike if/when the dropper needs service/rep., or does it still accept a traditional dumb post?

    • With the longer reach and shorter stems by 10-20mm, this should counter the slacker head angle and higher trail somewhat. BMC have definitely sacrificed some nimbleness for stability with this new bike though…

  2. The integrated dropper without compatibility with other brands or standard posts is ridiculous. Why did they bother? Why should I think BMC could make a better dropper? Why the heck is it oval? Why did they limit the adjustment range? Why isn’t the stroke adjustable? Why is it limited to 2 positions? Why should something so proprietary excite anyone? What if I want more setback? Why is 2.28″ considered enough tire clearance?

    This bike sucks unless you’re paid to ride it. Countdown until they change it again for “reasons”.

    • It makes sense for a race oriented bike to have less options to save weight. Plus, this seatpost is far less likely to develop play due to the shape

    • It’s oval to reduce angular play. They limited the range to make it lighter because XC. No dropper has adjustable range other than OneUp, because no one wants that. They limited it to 2 positions because no one needs an intermediate position with only 90mm travel, nor on an XC bike (you’ve obviously never ridden with a dropper), and doing so would add weight.

      It excites people that are into light XC bikes; the fact that this dropper is 200g lighter than any other dropper you can get. All of these are questions you could have easily answered yourself if you thought about it for 10 seconds before rushing to the comments to complain about something you would never buy anyway.

      Do you b#tch like this about every road bike with a seat mast?

    • As a XC weenie… this kinda checks a lot of boxes. If the thing fits, how much adjustability do I even care about? I don’t adjust my seat once it’s dialed anyway. People keep telling me to ride a dropper post, but I think they’re kinda heavy for the benefit. But a super light one makes me more likely to use one. And I’ve never ridden more than 2.28″ in the rear. 2.4″ in the front sure, but 2.2 or 2.25 in the rear is fine for XC IMHO (and at my weight… which is about 180 loaded). Anyway, yeah, not for everybody, but I didn’t see anything that made it disqualified from consideration. Might be a little slack for my taste, but that’s about it.

  3. Shafty and steve are both spot on. Comments always beat any “news”, jornalism died. This website name should be change to PR-Bike.com

  4. They forgot to add rear brake postmount. Also missing kashima dampers on the 01 Two. XTR treated like a 2nd grade group. Wonder if the XTR dropper remote is compatible. Maybe even the new XTR front shifter has correct cable pull to replace the not so smooth looking BMC suspension lockout. Makes me want to go for the frameset and find out

  5. They forgot to add rear brake postmount. Also missing kashima dampers on the 01 Two. XTR treated like a 2nd grade group. Wonder if the XTR dropper remote is compatible. Maybe even the new XTR front shifter has correct cable pull to replace the hideous BMC suspension lockout. Makes me want to go for the frameset and find out

  6. As someone who looks at a bunch of parts lying around my bike room and wonders how I can make a bike out of this random stuff I find all this system integration to be a bit off putting. However these swiss mountain bikes are slick. I love the way skinwalls look on new mountain bikes. Not sure how I would feel after a couple of rides.

COMMENT HERE: (For best results, log in through Wordpress or your social media account. Anonymous/fake email comments may be unapproved or deleted. ALL first-time commenter's posts are held for moderation. Check our Comment Policy for full details.)

This site uses Akismet to reduce spam. Learn how your comment data is processed.