Specialized Stumpjumper 15 Pro first ride review

The 15th generation of the full-suspension Stumpjumper is designed to be the “one bike to rule all trails”, says Specialized, which is a seriously bold claim. It also, more than likely, explains why there’s no longer a Stumpjumper EVO in the range.

The Pro model ridden here is the second most expensive bike in the line-up and shares a lot of similarities with the top-end S-Works bike in terms of the wheels, suspension and frame (although it forgoes the carbon rocker link). However, it misses out on the pricier gearing and brakes.

In an attempt to meet its lofty claim, Specialized has gone to town on development and, with the help of Fox Suspension, created the new, highly tunable GENIE shock, which you’ll see on all but one of the Stumpy bikes for 2025. For more details, read our news story on the Specialized Stumpjumper 15 here – in this first ride review, I'll focus on how it rides.

Alongside the new shock, the new Stumpjumper is treated to more geometry adjustment – similar to what we’ve already become accustomed to on the outgoing Stumpjumper EVO. There are also changes to the frame shape to improve a number of things, including the all-important seatpost insertion depth.

I spent two days in Canada during the launch, getting to know the new Stumpjumper 15, and racked up a decent amount of riding.

With tyres in the dirt, it became clear this new bike is an impressive bit of kit. More than that, though, thanks to all that geometry adjustment and the ability to tweak the shock to suit your riding or the terrain you’re on, it’s clearly very adaptable and versatile.

While it retains the lively, reactive feel of the old bike, get stuck into demanding trails and it’s harder to find the new Stumpjumper's limits, making you want to push this bike as hard as you possibly can.

Specialized Stumpjumper 15 Pro frame and suspension details

If you’ve kept a close eye on the Specialized range, the shape of the new Stumpjumper 15 will look very familiar.

That’s largely because it takes a number of design cues from the motor-assisted Turbo Levo SL, even down to ditching the frame’s sidearm.

Specialized says this was done to improve packaging within the front triangle, creating more room for the new, chunky shock, as well as helping with seatpost insertion depth. That’s improved by 50-70mm depending on frame size and there's more than enough space for a water bottle.

Even though this structural part of the frame has been removed, the word is that this bike is stiffer and just as strong as its predecessor.

At present, the Stumpjumper is only available with a FACT 11m carbon frame. In the case of the Pro (along with the other, cheaper models), that means a carbon front and rear triangle, but no carbon rocker link as featured on the S-Works model.

Rear-wheel travel has been upped to 145mm (from 130mm), but continues to be delivered using the thoroughly proven four-bar Horst-link suspension design.

Now, here comes the really interesting bit. Controlling the 145mm of rear travel is the new Fox GENIE shock.

This nifty little unit features three air chambers inside (two positive, one negative). Both positive chambers (the massive outer sleeve and inner eyelet) are connected to provide a coil-shock like feel through the first part of the travel.

That means a supple, sensitive initial stroke to help keep the tyre gripping and provide more comfort as you sink a little deeper into the travel.

Close in on the final 30 per cent of that 145mm and the ‘GENIE band’ inside the shock slides up and over air ports, closing off the bigger of the two positive chambers, effectively decreasing the spring volume and upping progression to ensure the shock can, in theory, handle big impacts without smashing through the last few millimetres of travel.

While the shock is a standard length (210x55mm), the spacers for the air sleeve and eyelet are custom and a full complement will ship with every bike.

Cables are all routed internally (not through the headset), the bottom bracket is threaded and it uses a SRAM Universal Derailleur Hanger to make finding replacements easier (assuming you’re not running the Transmission rear derailleur that features here).

Down tube storage comes courtesy of the updated SWAT 4.0 compartment. This uses a short lever to open and close it, while weatherproof sealing is said to have been dramatically improved over the previous iteration.

Specialized Stumpjumper 15 Pro geometry details

Although the size S1 and S2 bikes roll on mixed wheels, sizes S3-S6 all come with 29in wheels as standard. Want a smaller rear wheel? Specialized offers an aftermarket link to make that possible.

While the previous Stumpy enabled some adjustment, the new bike adopts the versatility of the Stumpjumper EVO.

That means it ships with three angled headset cups (the middle position offers a head angle of 64.5 degrees), while you can adjust bottom-bracket height (and the effective chainstay length slightly) by 7mm via the flip chip located in the Horst-pivot at the chainstays.

In the higher of the two settings, the bottom bracket sits at a claimed 337mm off the floor, with 38mm of drop between the wheel axles.

The chainstay length for the S3 bike I rode is 435mm in this setting, although the larger S5 and S6 sizes get longer 445mm offerings to help better balance the rider between the wheels.

At 77 degrees on the S3, the seat tube angle is a touch steeper than the old Stumpjumper and although it’s the same length (405mm), thanks to the increased insertion depth, you can now comfortably fit a longer-drop post inside. In this case, the S3 comes with a 185mm-travel post.

Specialized Stumpjumper 15 Pro specifications

To accompany the Fox Factory-level GENIE shock, there’s a Factory-level Fox 36 fork up front, complete with the new GRIP X2 damper and masses of adjustment.

The 29in wheels use Roval’s new Traverse SL carbon rims and are laced to Industry Nine hubs. These are wrapped in Specialized’s own tryes; a Butcher Gripton T9 at the front and a faster-rolling Eliminator Gripton T7, both in the GRID TRAIL casing. This suggests that although it's more capable, this is still a trail bike at heart.

The SRAM Maven Silver brakes are a real talking point. Specialized uses these punchy stoppers on all the new Stumpjumper 15 bikes, which considering SRAM’s gravity focus with these brakes, might seem like an unusual choice.

SRAM also supplies its X0 Eagle AXS Transmission gearing.

Specialized Stumpjumper 15 Pro ride impressions

I only had two days riding the new Stumpjumper 15 Pro while on the launch on Vancouver Island.

That limited what I could and couldn’t do somewhat, but thankfully I was able to get some consistent laps in on the same trail to experiment with shock setup – one of the key focal points of the new bike.

Setup

The Specialized mechanics were on hand to help with setting up suspension and, in typical press-camp fashion, that meant there was little time to tinker, measure and take notes.

Still, the sag at the rear was a little over the 30 per cent mark, while I set the fork up to my preference, based on settings I’ve used previously.

During my first day on the bike (ahead of a day changing shock settings), the only thing I changed was the fork pressure. This was simply to better balance the supple rear end of the bike and prevent the front wheel pushing through high-load turns.

Specialized Stumpjumper 15 Pro climbing performance

Thanks to that steep seat tube angle, the seated climbing position feels quite upright and very comfortable.

Although the shock sinks into the early part of the travel quite easily in the stock setting (one band inside the sleeve and a 0.2 spacer in the eyelet), things stay relatively stable when you grind your way up the hill.

It remains sufficiently active to track trail imperfections, though, helping to ensure limited slip and spin between the rear Eliminator tyre and the trail.

Even when perched right on the front of the saddle, tackling steep, 20+ per cent inclines, I never struggled with the front wheel lifting or wandering.

Specialized Stumpjumper 15 Pro descending performance

In many ways, the latest Stumpjumper 15 Pro reminded me of my time aboard the early Stumpjumper EVO around a decade ago.

That's not because it shares the same geometry, spec or travel figure, but because at the time, the EVO felt like one of the most capable 29ers on the market – especially considering the 135mm of travel it had on tap.

The Stumpjumper 15 has more travel, but in a world where we’re getting used to more and more bounce at both ends, it was impressive how controlled and confident things felt, even when venturing onto trails you’d normally reserve for enduro bikes.

Dropping into fast, twisty trails, I was instantly impressed by the smooth, almost silent ride of the new Stumpy.

Specialized says it tried to closely mimic the feel from its long-travel Enduro during the first 100mm or so of the Stumpy’s travel and I’d say it has, for the most part, achieved that aim.

It’s certainly supple and forgiving when rattling through chatter and braking bumps, with only the Eliminator rear tyre holding it back when I really wanted to push hard, due to the lighter casing. This needs more air inside it to ensure it doesn’t deform too easily.

On repeated runs riding the same trail, I swapped the volume spacers in the shock’s sleeve – the ones that’ll alter how that first 70 per cent of travel feels.

With zero spacers in there, while the Stumpy felt plush and comfy, it lacked some of the support I was after when loading the bike up through the bermed turns.

Packed with the full complement of four spacers, it feels more like the Stumpjumper of old. There’s more pep in its step and a far livelier ride, but hit a spread of roots or string of braking bumps and I soon found myself holding on tighter and missing the comfort of the previous lap.

What’s interesting here, though, is at both ends of the setup spectrum (zero spacers versus all four spacers) and without touching the eyelet spacer, I was using the same amount of travel.

After running through multiple variations, I switched back to the stock setup for reference and felt happy with the compromise, thanks to the ample support and impressive level of comfort.

I felt I could still weight the bike meaningfully as well as throw it about when I wanted to, but I felt confident and controlled when charging into the unknown.

This became particularly important on one of the later trails on the final day, which started with a series of blind jumps, hefty landings and compressions, before plunging down a long, steep and roughed-up hillside.

Despite there only being 145mm of travel on tap, I never felt I was being rattled around or on the edge of control. Slap a grippier, tougher tyre on the rear and this thing will positively rip just about any trail. It really does feel that capable.

And let’s not forget, I was running it in the middle head-angle position and highest bottom bracket setting. So, in theory, the handling could feel even more confident if you made some simple changes.

Add to that how easy it is to tune the new GENIE shock and it’s clear how adaptable the new Stumpjumper 15 could be.

While I may have questioned the choice of speccing Mavens when I first jumped on the new Stumpjumper, knowing how hard you can push this bike highlights why it wasn’t a bad move at all.

If Specialized had opted for a lighter-weight, less powerful option, I’m sure I’d have had more to grumble about on the longer descents. But, in this case, I didn’t.

Well, aside from the tyre casing choice. This is a trail bike and slapping sticky, heavy tyres on it won’t do you any favours when going uphill, but even upping the rear casing to something a touch beefier wouldn’t exactly hold it back drastically, only opening up what’s possible on this bike and adding even more confidence into the mix.

Specialized Stumpjumper 15 Pro early verdict

After just a couple of days aboard the new bike, it’s clear Specialized has done a good job of proving that by adopting much of the Stumpjumper EVO’s geometry and adjustment, alongside creating a new, best-of-both-worlds shock, you can have your cake and eat it.

Look out for a full review soon.