​Specialized Stumpjumper 15 Evo Expert: More suspension travel, fewer excuses

One of the privileges we enjoy as BIKE editors is being able to choose a bike for one or two seasons, which we then ride as often as possible so that we can discuss any potential faults and wear and tear and, above all, report on how the bike performs.

These days, some romantic relationships between two people last less time than my fling with a long-term test bike, so you need to choose your cycling partner wisely – otherwise you might end up getting bored with each other and on each other’s nerves. Not a pleasant prospect in your favourite sport.

For the next two cycling seasons, I’ve gone for the Specialised Stumpjumper Evo Expert. Why? I want to do a whole lot with my bike: from epic rides to bike parks – and, of course, I want to pedal myself rather than let the motor purr away. In short: a bike for everything.

Six years ago, I rode the Stumpy’s predecessor’s predecessor. In my view, it was almost a classic enduro bike and therefore exactly to my taste. It was a 29er, just like the new one, with 150/140 millimetres of suspension travel, weighing 14 kilos and, back then, still featuring the distinctive single-sided ‘shock strut’ as its hallmark – a narrow, asymmetrical carbon strut between the top tube and seat tube. I rode that bike for two years and didn’t want to part with it – I’d enjoyed it so much. Naturally, that’s exactly what I’m expecting from the new Stumpy now.

So, bring it on!

Stumpy is growing up (again)

For a long time, the Stumpjumper was the mountain bike for people for whom an enduro bike was too much and a short-travel trail bike wasn’t enough. Now it is once again. After 2020, the Americans tuned the Stumpy more towards a stiff trail bike with limited suspension travel. The 15th generation returns to the original concept. In the EVO version, 145 millimetres of rear suspension travel is paired with a Fox 36 Performance Elite front fork offering 160 millimetres of travel.
I’m 1.78 metres tall and opted for size L; at Specialized, this is called the S4 with a reach of 470 millimetres – our measurement came out at 468.

The frame is made entirely of carbon and, according to the manufacturer, weighs 14.48 kilograms fully kitted out in size S4. We actually weighed it at just 14.39 kilos. This means the Stumpy isn’t exactly a featherweight, but for such a powerful trail bike, it’s certainly no sack of cement either. The SWAT 4.0 storage compartment for a inner tube, tools and an emergency bar is located in the down tube. Handy for anyone who wants to ride without a rucksack – a dedicated tool clip is fitted beneath the bottle cage.

Sizes S1 and S2 come as standard in a ‘mullet’ configuration with a 29-inch front wheel and a 27.5-inch rear wheel. From size S3 onwards, the bike features two large wheels. The chainstays increase in length from 430 to 445 millimetres to match the frame size. This ensures that smaller riders don’t end up with a bike that’s too long, whilst taller riders don’t end up with one that’s too rear-heavy.

A genie in a bottle powered by air pressure

Specialized is particularly proud of the Genie shock. Specialised developed the shock in collaboration with Fox. Instead of a single positive air chamber, the system features two interconnected chambers. This ensures a large volume of air is available throughout the first 70 per cent of the travel. The rear suspension is designed to respond sensitively and behave in an almost linear fashion – similar to a steel spring. In the final third of the travel, the outer chamber is isolated, the characteristic curve becomes more progressive, and the shock thus resists bottoming out.

It sounds like a technical marvel, but it rides unobtrusively. If the shock is set up correctly, there’s plenty of traction on the rear wheel. Small bumps are absorbed discreetly, root sections lose their fear factor, and there’s enough support in banked corners and when pumping. The 145 millimetres feel like more. Only on very blunt, flat drop landings has the shock bottomed out a few times so far. But that was also down to the fact that I like to ride with plenty of sag and low compression. A couple of clicks on the blue knob and the bottoming out – which I’d actually provoked myself – stopped happening.

Uphill without a penance walk

On a bike fitted with a Fox 36, a piggyback shock and weighing just under 14.5 kilograms, you’re certainly not going to turn into climbing prodigy Braydon Bringhurst (yes, I know: Braydon rides a Canyon). Nevertheless, the Stumpjumper climbs more than willingly. The rear end stays fairly stable when pedalling at a steady pace and offers plenty of traction on technical climbs. Very effective and a real mental boost: flick the lever, engage the platform mode, and nothing wobbles anymore.

The riding position is central, although the effective seat angle becomes slightly flatter as the frame size increases. On the S4, it’s 76 degrees. That’s comfortable for long rides. The high stack – I used a few spacers under the stem – and the handlebars with a 50-millimetre rise create an upright riding position. Good for control and visibility – just right for me. It’s not down to the Stumpy that I constantly have to remind myself to move forward to maintain a central position on the bike. I have that problem on all bikes.

The 10–51-tooth cassette offers plenty of gear range, whilst the Shimano XT Di2 electronic groupset shifts quickly and reliably. Its battery is housed safely within the rear derailleur; if it takes a knock, the system can cause the cage to move out of the way and then return to its original position. Not so long ago, I was slagging off electronic gear systems, just like tubeless tyres, clipless pedals, Friedrich Merz and uncontrolled rearmament. But this electronic stuff actually works really well, provided I use my head and charge the little battery pack.

Downhill, it’s almost like an enduro bike

When you’re heading downhill, that’s when the fun really begins. The 64-degree head angle, the high front end and the Fox 36 – not to mention the tractor tyres – really boost your confidence. At the same time, the bike is really agile. A mini-enduro – seriously! And yet it’s blessed with incredibly playful handling. Up front, the soft Butcher T9 provides plenty of grip, whilst at the rear the Eliminator T7 rolls more easily. The GRID Trail casings suit its all-round remit well, but can lose stability at aggressive speeds, during hard impacts and in wet conditions. Anyone who frequently rides in bike parks or over sharp-edged rock should consider a more robust casing at the rear. The tyres are also available in a radial version (which is what I’d been hoping for), but they aren’t fitted as standard on the Stumpy.

With its GRIP-X2 cartridge, the Fox 36 Performance Elite offers the same extensive damping options as the more expensive Factory version – just without the gold Kashima coating and the associated premium price. At the rear, there’s a Float X Performance Elite GENIE with a piggyback reservoir, compression and rebound adjustments, and a platform lever. The suspension thus offers plenty in reserve for long, tough descents, but requires a bit of patience when setting it up. Those who enjoy fiddling with the dials will be in their element. If you just want to pump some air in and get going, you should stick to the recommended default settings to begin with

In addition, the geometry can be adjusted using headset cups and a flip chip. The steering angle can be set steeper or flatter, the bottom bracket raised, thereby shifting the handling from that of a nimble trail bike to that of a smooth-running mini-enduro. The differences aren’t just marketing hype, but can be felt on the trail.

‘Expert’ means: expensive, but not outrageously so

The spec hits the sweet spot where high-end begins, without losing touch with reality entirely. €7,000 is a lot of money – that’s how much the Stumpy Expert costs in that stylish colour: gloss pistachio. (The S-Works version comes in at €14,000).

The Shimano XT four-piston brakes engage with a 203-millimetre disc at the front; at the rear, the discs are also 203 millimetres from the S3 model onwards. The Roval Traverse aluminium wheels, with an inner width of 30 millimetres, are less glamorous than carbon rims, but well-suited to a bike that’s actually intended to be ridden over stony terrain. A PNW Loam seatpost on my bike offers 200 millimetres of travel. That means I don’t have to push it in or pull it out any further by hand.

All in all, the Stumpjumper 15 EVO Expert isn’t a specialist, but a remarkably talented all-rounder. It climbs better than its 160-millimetre travel would suggest, and rides downhill with more confidence than its 145-millimetre rear travel would lead you to expect. A thoroughbred enduro bike remains more stable in high-speed sections, whilst a lighter trail bike accelerates more briskly on gentle trails. In between, however, the Stumpy covers an astonishingly wide range – just right for me.

On top of that, there’s this feeling that the bike really suits me. When I get on it, it feels like slipping into my favourite running shoes. The Stumpy and I become one: the wide cockpit with the slim grips and the short stem – brilliant! The pleasing geometry. The intuitive handling. With a bike like this, technically tricky rock traverses become a right bit of fun. I don’t spare a single brain cell (I’ve only got two) thinking about taking a tumble or messing up the balancing act. The same goes for rock roll-offs, which on some other bikes have left me struggling and on edge – you get the picture!

What I haven’t done with it yet: I haven’t really put it through its paces in the bike park. Let’s see how the Stumpy copes with that. I’ll let you know.

Conclusion: The Specialized Stumpjumper 15 EVO Expert is a trail bike for riders who like to ride all kinds of terrain and would rather not buy several bikes. It’s responsive, fun to ride, smooth enough and has just the right amount of pop to make those jumps fly.