SPECIALIZED S-WORKS STUMPJUMPER 15
£10,000 The new Stumpjumper 15 is the most versatile model yet
This latest version of Specialized’s long-standing, doit-all trail bike is said to be more capable and versatile than ever, with longer suspension travel and new shock tech. Which maybe explains why they’ve dropped the souped-up Stumpjumper EVO from their line-up. But can it live up to these claims?
THE FRAME
Like the other Stumpy 15s, the S-Works model is made from Specialized’s ‘FACT 11m’ carbon fibre, as is the rocker link, on this top-end bike only. At the rear, travel has been increased to 145mm, still dished out by Spesh’s ‘FSR’ Horst-link suspension platform. One big potential improvement is the Fox Float Factory shock, which features Specialized’s new Genie technology. This gives it two positive air chambers, which can be adjusted using included spacers. The outer chamber (housed within the shock sleeve) manages the first 70 per cent of the travel, while the inner one handles the final 30 per cent. These can be tuned independently.
The asymmetrical ‘Sidearm’ supporting strut of the previous frame is gone, allowing deeper seatpost insertion and more room for a water bottle. And the ‘SWAT’ down tube storage is now easier to access and better sealed.
This new bike has adopted much of the late Stumpjumper EVO’s geometry and adjustments. There are three angled headset cups, each altering the head angle by one degree, and you can tweak the chainstay length and bottom bracket height by 7mm using a flip-chip in the chainstay pivots. Our S3 size had a head angle of 64.2 degrees (middle setting), 435mm chainstays and a BB sitting 334mm off the floor. Reach is a reasonable 450mm, while the seat tube angle is a steep 78.3 degrees.
THE KIT
Up front is a top-end Fox 36 fork with GRIP X2 damper (although our bike had the older GRIP2) and 150mm of travel. This is paired with a wireless SRAM XX SL Eagle AXS Transmission and RockShox Reverb AXS dropper, plus SRAM’s Maven Ultimate brakes. Roval Traverse SL II carbon rims – redesigned to boost comfort and puncture resistance – are wrapped in Spesh’s Butcher and Eliminator tyres.
THE RIDE
At just 13.58kg and with the fast-rolling Eliminator tyre on the rear, the S-Works Stumpjumper 15 isn’t afraid to work against the gradient. In fact, it surges forward with every pedal stroke
through its short 165mm cranks. It helps that the rear end stays fairly still while you’re sitting down and pedalling. Spesh’s goal of creating plush initial travel means there’s a bit of bob, but you don’t feel like you’re wasting power. It pays dividends when snaking up root-riddled inclines, where the rear wheel tracks fluidly in and out of divots, keeping the tyre gripping as you climb.
When descending, the Stumpy 15 feels similarly eager, and is easy to pick up and place wherever you want it. However, there’s a reassuring air of calm when things get rowdier, with the slack front end and well-proportioned geometry giving you a confident stance on the bike. With the stock set-up, you’d be fooled into thinking there’s more travel on tap than there actually is, because you can really push it hard. There’s enough comfort to stop you feeling battered on longer downhills, but ample support to help you eke out speed by pumping trail undulations.
Should you want to add extra pep, adding more spacers to the shock’s outer sleeve makes the bike feel more like the Stumpjumper of old, delivering even more support and feedback, but a less comfortable ride. However you set it up, it’ll be the rear tyre that hits its limits before anything else – get a tougher casing out back and you’ll boost performance even further.
Thanks to the geometry adjustment and tunable shock, there’s scope to really tailor the Stumpjumper 15 to both your riding style and the terrain you’re planning to ride, making it a really versatile bike. But even if you don’t want to tinker with flip-chips and volume spacers, in its stock setting, this is a trail bike that’s ridiculously fun to ride and far more capable than its 145mm of rear-travel might have you believe. Rob
A riot of a bike that’s versatile, easy to tune and extremely capable, albeit pricey