First Look: Specialized's New Carbon Stumpjumper Ditches the Horst Link

Specialized has pared the Stumpjumper range down to just six bikes and a frameset, all designed around 29" wheels. That's right, there's no small-wheeled Stumpy in the catalog, but the new extra-small 29er offers more standover clearance than last year's 27.5" wheeled bike of the same size.




The least expensive Stumpjumpers, the $2,199 Alloy, and $3,199 USD Comp Alloy, are both aluminum frames that get the same geo as the carbon bikes but similar Horst Link rear-suspension to the previous Stumpjumper. More on that later, though.

Carbon fiber models start at $3,999 USD for the Comp, while the top of the range S-Works version we have for our upcoming Field Test series retails for $9,499 USD. That gets you a wireless AXS drivetrain and seatpost, Factory-level suspension from Fox, and Roval (Specialized's house brand) carbon wheels. All that and a bunch of other fancy things add up to exactly 27 pounds on my scale. Want to build your own dream Stumpy? The frame/shock will cost you $2,799 USD.






The All-New Stumpy Frame

The side-arm frame design is back on the latest Stumpy, but every single tube is new and Specialized say they spent a ton of time and effort making this the lightest version yet. Much of the savings came from taking out the "lazy carbon,'' which is the stuff that was just adding grams without adding strength, and methods they learned while doing the also-new (and ridiculously light) Epic frame were put to use when creating the Stumpjumper.




Claimed frame weight is 2,240-grams with the shock and small bits, which makes it 100-grams less than the previous Stumpy frame and 510-grams less than the also-also-new Stumpy EVO frame. Specialized has been busy lately.

Onto the details. My must-have list for a trail bike includes stuff like ISCG tabs, a threaded bottom bracket, room for a large-sized bottle inside the front triangle, and a ton of well thought out frame protection. I'd also insist that the only way internal cable routing is acceptable is if it's pass-through. Yes, there are tricks to make it easier, but I'm getting damn tired of trying to fish a shift or brake line out of a not-big-enough opening. And having to remove a bottom bracket to hook up a dropper post? That's unacceptable. Specialized agrees with my list, it seems, including the pass-through routing.





SWAT is back, of course, and this version is said to be the lightest yet, with an internal carbon 'skeleton' of sorts that helps retain tube rigidity. There's also a spring-loaded multi-tool inside the steerer tube that pops up like you're playing Whack-a-Mole, but be ready to lend it out every time you stop - it's very convenient.


A Stumpjumper Without Horst Link Suspension

Specialized has employed Horst Link suspension since basically forever, including every single full-suspension Stumpjumper model... But not anymore. The new Stumpy ditches the Horst Link in favor of a single-pivot layout with a linkage-driven shock, and the carbon fiber rear-end gets a flex pivot on the seatstays instead. Is it me, or does 2020 keep getting weirder?




Let's go back and talk about Horst Link for a second, which is named after a guy named Horst but his last name isn't Link. You can tell it's a Horst layout if the rear pivot sits below the axle, and the four bars of this four-bar system include the chainstays, seatstays, rocker link, and the shock itself. Pivot locations and shock tuning mean you can't really say, ''A Horst bike ride like this," but many riders associate the design with active, forgiving suspension that can provide loads of traction. And that's what the previous Stumpy was known for.


Specialized isn't about to ditch the Horst, though, with the less expensive aluminum Stumpjumpers still using a revised version - Specialized said the whole flex pivot thing is way more difficult to do in aluminum. They also said that they've worked to make the alloy, Horst Link Stumpys ride similar to the single-pivot carbon Stumpys, but I don't have one of those on hand to confirm that claim. That said, it'd be good to include one in a value-oriented Field Test down the road.




S-Sizing and Adjustable Geometry

Looking for a large? Sorry, that's now how this works and we're gonna be better off for it. While traditional sizing and long seat tubes used to lock riders into a fame size, S-Sizing sees all the frames get a ton of standover clearance that's combined with long-stroke dropper posts. The idea is that you can choose a reach and wheelbase that work for you instead of saying, "The medium's seat tube is too short, so I have to go to the large."

Sizing runs from S1 with a 410mm reach to S6 and its 530mm reach (my S4 is 475mm), and Specialized says that if you were on a medium previously, you might like the Stumpy in S3. But you don't have to - you could go to the shorter S2 if you want a bike that's easier to toss around, or up to S4 if your trails require a bit more stability.




Let’s look at a few numbers in the low, slack setting because we all know that’s where it’s gonna end up. That gives you a 65-degree head angle and 76-degree seat angle, as well as 42mm of bottom bracket drop that puts it at 333mm high. If you want the bike a bit higher and quicker handling, the flip-chip at the clevis shock mount can be used to add have a degree and 7mm of bottom bracket height.

I've been spending a ton of time on the new Stumpjumper, since it's one of the bikes we'll be including in an upcoming Field Test. Stay tuned for those reviews a little later this year.

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Reviews and Tech First Looks Trail Bikes Specialized Specialized Stumpjumper