S-Works Stumpjumper FSR
Clockwise from top left: Carbon fibre crown/steerer; Future Shock S120 fork; Carbon back end; rocker linkage and AFR shock
Two views of the Brain
Stumpy variants – top left is the 29er, top right the alu-framed FSR Pro and above the women’s Safire
Following last year’s launch of the swoopy carbon fibre Enduro SL, Specialized’s Stumpjumper FSR has been completely redesigned – at first glance, the 2008 Stumpjumper looks just like a somewhat slenderer Enduro.
In common with its long-travel sibling, the 120mm travel Stumpjumper features a repackaged version of Specialized’s FSR rear suspension design with a vertically-mounted shock and full-length (although curved) seat tube. And like the Enduro, the Stumpjumper uses Specialized’s own front and rear suspension components.
At the back is an AFR Shock rear shock, with new slimline FlowControl Brain inertia damper can mounted near the rear axle. Up front is the smaller brother to the dual-crown Future Shock E150 fork, the Future Shock S120. In an interesting move, Specialized has designed the S120 fork and Stumpjumper frame as a system. The fork has a tapered carbon fibre crown/steerer that takes a 1.5in lower headset race and a 1.125in upper one. This is said to eliminate sharp angles between steerer and crown that could act as stress risers. Designing the fork and frame together has also let the engineers align the lower headset race with the downtube to reduce bending moments and minimise the amount of material that has to be used.
There are downsides to this approach, the most obvious of which is flexibility. Retrofitting some other fork into the Stumpjumper frame is going to be non-trivial and it may be a little while before your handy local bike shop has a shelfload of off-road friendly 1.5/1.125in headsets. The less expensive Stumpjumper models will have an aluminium frame, conventional 1.125in headset and non-Specialized forks, so you won’t be able to put a Future Shock on those either.
Needless to say, the S120 fork is tuned to exactly match the behaviour of the AFR/FSR back end. The fork has a FlowControl Brain too. Specialized has put the fork’s spring and damper both in the right-hand leg – there’s nothing in the left leg at all. In another example of integrated design, the dropouts are designed to work with the oversized end caps of Specialized’s own Roval hubs (of which more later) to improve steering precision. The dropout slots are also angled forwards in the now-conventional style.
The S-Works Stumpjumper FSR is claimed to be the “lightest production XC Trail bike in the world” at 23.2lb, helped along by the carbon frame being 200g lighter than the 2007 one. Leaving aside the question of what exactly counts as an “XC Trail” bike, that’s clearly impressively light. You’ll have to pay a penny under four grand for the privilege, of course. But fear not – cheaper Stumpies will be available, with the aluminium FSR Comp starting at £1,499.99.
The range will feature a couple of Stumpjumper spin-offs. First there’s a 29in-wheel model (in a frankly rather unpleasant green/brown colour scheme), plus a 29er Stumpjumper hardtail. Specialized has also given all its women’s bikes different names – the Safire is the women’s version of the Stumpjumper FSR, also available in carbon fibre or aluminium.
More Spec’ stuff soon…