Specialized Stumpjumper FSR Comp Carbon 650b (2017) review

Specialized’s Stumpjumper FSR Comp Carbon family covers every possible modern trail bike base, including 29er and plus versions, but it’s a conventional cruiser rather than a radical charger.

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A mid-range composite front end is mated to an M5 alloy back end, and the down tube features Specialized’s unique SWAT internal storage hatch under the bottle cage. The RockShox Monarch RT shock gets a bespoke ‘Rx Trail Tune’ and ‘Autosag’ side valve for easy set-up of the 150mm stroke.

The rear of the shock uses a custom cradle to connect to the shock driver yoke, which in turn connects to the U-shaped linkage of Specialized’s FSR kinematic. A curved seat tube and 148mm wide Boost rear hub allow super-short asymmetric chainstays, and gear and dropper post cables are all routed internally. The down tube sports a big protective plate in front of the PF30 bottom bracket shell and there are also chain guide mounts.

The tight grip of the SRAM GX rear mech and Race Face direct-mount chainring meant we never felt the need for a chain guide, though. The RockShox Yari RC fork is a seriously tough unit, while the Specialized Butcher and Slaughter tyres get reinforced Grid casings.

The 200mm front rotor on the size L and XL bikes amplifies the power of the SRAM Guide R brakes. Specialized’s bar and stem suit the trail character and the own-brand dropper is reliable, if eye-wateringly rapid in action. Specialized’s 29mm internal width wheels add tyre volume, but reduced spoke count affects stiffness.

While the Autosag shock drops you into the right sag spot in percentage terms, the RX Tune is very keen to push through its travel. That meant we soon added air pressure and volume-reducing bands to the Monarch shock body to increase support. It’s still a very mobile ride under pedalling, though — it could use an additional low-speed compression damping setting between the fully open or almost locked options of the RT lever.

With the carbon mainframe, oversized bottom bracket, stiff Boost rear end and semi slick tread on the Slaughter rear tyre we were expecting prompt acceleration and easy momentum maintenance, but with wattage wasted by the soft rear end it meant it struggled in power play situations.

While the 67-degree head angle and 620mm top tube look good on paper, the Stumpy feels more compact and prone to stumble in aggressive turns than other longer wheelbased, bikes, such as the Orange Five S Reverb or Mondraker Foxy R. Even the stout 35mm legged, Boost width Yari fork can’t add sharpness to the manners of the heavy but flexy front wheel. When we tried to bully the front end out of understeer situations or drag it in to an apex it felt vague rather than visceral.

While ragged-edge riding might not be its forte, there’s still a lot for less radical riders to like about the Stumpjumper. The relatively conventional geometry doesn’t feel as initially intimidating as the stretched and slack-angled bikes here if you’re used to an older bike, and the shorter wheelbase and back end make it easier to steer through tight, slow speed singletrack.

The Autosag feature takes the guesswork out of shock set-up and the linear shock character and very little chain influence on the suspension action leaves the rear wheel to roll up and over roots and rocks with consistent connection, so you don’t need to manage technical terrain traction yourself. The long negative spring in the Yari fork means an equally smooth ride up front and the tubeless-ready wheels and tyres add more potential float.

There’s the option to add even more float by choosing the plus-tyred Stumpjumper 6Fatty or get a faster rolling, more stable ride from the 29er model. They’re both still short and nimble, so if you want a more radical feel try the new Enduro.