Followup Review: Specialized Stumpjumper 15

When the new Stumpjumper 15 launched back at the beginning of July, it came complete with plenty of controversy fodder. Specialized had the dubious pleasure of launching the first mainstream wireless-only bike, and the new Stumpy shipped with a proprietary shock as well. That combination set the mountain bike internet up for a fun few months of virtual hand-wringing, finger-pointing, and general discord.

For the first few rides on the new Stumpy, I felt rather acutely aware of all that noise. Every ride I took on the bike somebody would stop to ask me about the shock, or the lack of cable routing. But all that speculation and “controversy” felt like it was directly opposed to my actual real-world experience on the bike. Out on the trail, this is a really easy bike to love. The experience of riding the new Stumpjumper is much simpler, more intuitive than comments sections would imply.

The Stumpjumper 15 is a bike that doesn’t distract me while I’m riding. I don’t find myself thinking about it that much, which is rather remarkable given how persnickety this line of work encourages me to be. But it accomplishes that by being very good, in a bunch of different arenas, so here’s my attempt to break through the haze of “damn, I love riding bikes” that has a tendency to envelop me while I’m out “reviewing” on it.

Build notes

I’ve been riding the Stumpjumper Expert build, and so far I’ve kept it dead stock. In a sort of hilarious happenstance, this review bike even came with the dropper height set perfectly for my legs. I like the build on this bike a lot, so here’s a quick hit list of components:

GX Transmission is still good and I still love it. Specialized’s Butcher and Eliminator tires are a great fit for the bike’s intentions, and I’m a fan of both. The Roval Traverse alloy wheels have stayed remarkably straight and true so far. However, I do wish they came with a faster-engaging DT Swiss ratchet in the rear hub. That’s an easy and affordable change to make though. The PNW Components dropper post has been absolutely excellent, and I get along well with all the touchpoints on the bike.

If I had to name my favorite component of 2024 so far, it would definitely be the Maven Bronze brakes featured on the new Stumpy. They’re really good. They feel excellent out of the box, and as a bigger person, I appreciate the braking power they bring to bikes like the Stumpjumper. I just don’t notice any real loss of performance between the Bronze and Silver or Ultimate versions of the Maven, and it’s so cool to finally see complete GX builds come with such proper brakes.

For years, before this gig, I tended to purchase GX level builds of complete bikes, and then immediately swap out the Code R brakes for something with more bite and power. I could write a whole manifesto on this (and might at some point) but good affordable, entry-level components get me just as hot and bothered as the blingy top end ones. Props to SRAM for making these and Specialized for speccing them.

All-in, this build spec leaves little room for complaint.

Frame details

Let’s get through the innocuous ones first: Specialized is really good at in-frame storage, and this newest iteration of SWAT is great. It’s lighter (and maybe easier to manufacture?) and is really easy to operate, while also being fairly waterproof.

The geometry adjustments on this bike are easy to use, and make a real difference in how the bike handles, and the frame fit and finish in general is tight and excellent.

And no, there’s no routing for a rear derailleur cable. I understand the weight this decision, from a brand as big as Specialized, carries. But I’d also offer three counterpoints:

1) We’ve dealt with this before. Many of us pitched a fit when brake cables started running inside the frame. However, it’s pretty easy to rig up something tidy with stick-on guides. I did this last year with a We Are One Arrival, and it worked well, looked good, and made it easy to swap brakes around. Yes, sticking cable guides onto your $3,500 frame is a bit silly, but the counterculture element has never been scared of a little arts and crafts time, right?

2) Specialized makes another 140 mm travel bike, the Status 140, that comes in a sweet pink color, has internal routing for that missing cable, and retails, as a complete bike, for the cost of a Stumpjumper frame. They’re not “forcing” anything on us.

3) A certain Specialized and Shimano athlete has posted something that looks an awful lot like an alloy Stumpy on Instagram a few times, and it certainly has a rear derailleur cable running inside the frame. Do what you will with that information.

Suspension performance (is this secret sauce special?)

The second ingredient to Stumpy-based comments outrage is the Genie shock on the back end of the bike. I explained how it worked in my initial piece , so now it’s time to go deeper on how it feels.

It feels really good. It also feels really good in a super “normal” way. I think that if I had been handed this bike in a “diaper” so that I couldn’t see the shock, I would have come away from my time on it convinced that it had significantly more travel than the 145 mm it possesses, and that it was equipped with a coil shock and a fairly progressive rear end.

The Genie shock delivers a ton of traction across a wide variety of trail scenarios, without really compromising my ability to get the bike off the ground - it’s not “stuck to the ground” but it does a good job of tracking through bumps and chatter. I think I most notice the Genie on repeated sharp, square-edged, small- to medium-sized hits. Specifically, there’s a trail that I ride pretty much every review bike on, that has a couple of sections where you jump into a pile of exposed roots running perpendicular to the trail. I know what those roots feel like to my knees and ankles on most review bikes.

But the Stumpjumper erases those impacts and smoothes out those sections effectively. The only other bikes that feel as good through here are high pivot enduro rigs. The only indication that the Genie is working hard in these sections is chain movement. The rear triangle is moving a lot more to absorb those bumps than bikes like the Transition Smuggler. But the bike doesn’t pack down into its travel, and it doesn’t feel dead or ponderous on mellow sections of trails. It’s a bit of a paradoxical feeling.

I end up experimenting with the fork to try to get the bike to feel more balanced. While I’m usually pretty happy with one volume spacer in the Fox 36, I felt like when I set it up to feel as supple and comfortable as the rear end felt, I was blowing through my travel and packing the fork down, even though I was using settings that I’ve liked with the same fork on other bikes. I ended up adding a couple of volume spacers in an effort to capture a little of that same sensation up front. I would be absolutely unsurprised to see Specialized bring something Genie-flavored to the fork market in the future.

Stock, straight out of the box, I think the new Stumpjumper is going to appeal to a lot of riders - it’s the sort of platform that makes you feel like you’re good at riding bikes, which is an easy sensation to sell. But this bike also comes with a whole bunch of adjustments to experiment with.

Playing across the spectrum of stump jumping

I rode the Stumpjumper in the stock “mid” headset setting, and “high” chainstay setting, with the stock volume spacer arrangement for a few weeks. Set up like this, the bike is rad. It’s snappy, it’s versatile, it’s supple, playful, all the adjectives you’d want from a trail bike.

But, Specialized makes it easy to deviate from that formula. So I played with different volume spacer arrangements, as well as the built-in geometry adjustments. With the headset in the -1° position, and the chainstays in “low” you get a 63° head tube angle, which lines up nicely with my typical preferences for a more aggressive bike. In this setup, the Stumpy begged me to charge. It wants to go places, fast, and I could totally justify bumping up to a 160 mm fork with 38 mm stanchions and gravity casing tires if I was mostly running the Stumpjumper in this geo configuration. This is where that Genie rear end also feels the most “special.” The bike feels longer travel than it should when I’m riding the sort of terrain this setup is tailored for.

I tried this setup without the stock volume spacer in the initial chamber, and while I liked how much traction the bike delivered here, ultimately went back to the stock setup.

Conversely, with the headset in the -1 position, and the chainstays back in “high” the bike feels a lot more snappy, a lot more “trail.” In this setup, I also tried running two spacers in that main chamber, and felt like that matched the geometry nicely. This was my “ride familiar trails like a hooligan” set up, where I was less concerned with traction and more interested in lofting every lip and pushing through corners. The added support there was welcome. In this setup, the bike feels quick and efficient uphill, and is a lot of fun in more rolling terrain.

Ultimately though, if I owned this bike, I think I’d stick to the stock volume spacer configuration. It’s fun to experiment with, but I really like the balance that the original setup strikes for the kind of riding I enjoy.

I would, however, definitely run the offset headset cup, and just alternate between +/-1° and the corresponding chainstay position depending on the sort of ride I was headed out for. The Stumpjumper’s adjustments make a meaningful difference, and suit this suspension platform very well. And I’m sure some riders will take this a step further and have a “going to the bike park” build of the Stumpjumper, complete with beefier tires, a bigger fork, and different shock settings, vs their daily driver. Versatile is an overused moniker, but I’m hard-pressed to think of a frame that deserves it more.

My one callout would be the decision to only allow mulleting via an aftermarket link. I wish you could throw a 27.5” rear wheel on this bike without spending extra money or buying the coil build. But I bet Specialized has run the numbers and determined that very few folks are actually mulleting their Stumpjumpers, so it’s no problem to just sell us weirdos an extra link.

Durability

This is a boring section. Nothing to report. No creaks, no issues, the adjustable headset has been silent, and the bike has continued to run quiet and smooth. That means I’ve been reaching for it more over the last few months, to avoid riding louder, less seamless bikes, and it continues to feel great.

Comparisons

I’ve ridden a few bikes in the last year that are nice analogues to the Stumpjumper. First, the Transition Smuggler . I think the Stumpjumper pedals as efficiently (or better) than the Smuggler with the shock open, and outperforms it in terms of traction and support. The rear end feels a lot “bigger” at higher speeds and on gnarlier trails. I’d happily put a 160 mm Zeb on a Stumpjumper, but would never dream of keeping it on the Smuggler. The frame details also feel much better considered on the Stumpjumper.

Compared to the Cannondale Habit LT , the Stumpjumper has a lot more traction. It doesn’t feel quite so spritely on the up, but also delivers quite a bit more climbing traction. And, when things get going fast, I’d much rather be on the Stumpjumper.

Compared to the Canyon Spectral , I like Specialized's approach to sizing better, and I’d rather ride an S4 Stumpjumper than a large Spectral. The Stumpjumper also felt more intuitive both in tight, slower trails and with the throttle wide open.

Ultimately, I think the Stumpy’s relationship with all three of those bikes is defined by the fact that its geo adjustments and rear suspension give it an edge that allows it to handle a broader range of riding well.

Compared to my REEB Steezl . I love my Steezl, there’s a reason I bought it, but man, the Stumpy feels really special. It’s lighter, snappier uphill, and it’s rather shocking how little I notice the 10 mm difference in rear suspension travel on the two bikes. Actually, I think in a blind test I’d say the Stumpjumper felt like it had more travel than the Steezl. I’m pretty confident that with a 27.5” rear tire and 160 mm Zeb, I could push the Stumpjumper harder and go faster in pretty much every scenario than I do on the Steezl, while also shedding a few pounds. That pains me to say since I do really feel at home on the Steezl.

For now

It shouldn’t come as a surprise that the new Specialized Stumpjumper 15 is really good. It rides well, can adapt easily to a variety of terrains and riding styles, and the rear suspension feels excellent. From a purely performance standpoint, I struggle to fault this bike on any front. If I was only going to own one mountain bike, it would take some serious external factors to make me choose something other than this Stumpjumper.