Specialized’s Stumpjumper is synonymous with trail bikes. After all, it's been in the Californian behemoth's line up for an incredible 34 years.
Frame and equipment: SWAT stash box and better matched suspension
In that time it’s changed radically from the steel hardtail that was first given the name. This is the latest Stumpjumper incarnation, and as this particular bike is an S-Works model, the frame is fully carbon, which helps keep bike weight to a reasonable 12.1kg. Specialized has been making carbon mountain bikes since 1988, so is well versed in making light but durable composite creations.
The Big S has also increased integration of its SWAT (Storage Water Air Tools) system. Previous incarnations have included hidden tools and add-ons to bottle cages, but the carbon Stumpy has a great big port in the down tube which increases storage without making the bike look like a Buckaroo donkey.
The bottle cage is housed on a clip-off port cover, under which a compartment big enough for a couple of supplied tool wraps, plus some food, or a jacket plus extras can be held. A bulkhead at the bottom of the down tube prevents items finding their way into the BB area.
Specialized includes a couple of handy tool wraps for sticking in the SWAT
In use the port is easy to access, and means we were able to ride further without a pack. Having a big hole in the down tube does have stiffness implications for the front triangle, but with a stiffer back end (more on that later) the axle to axle stiffness is barely affected – not enough to notice anyway.
As with many modern carbon frames, cable routing is internal, but thanks to the moulded-in full length cable guides there’s no rattle and they didn’t get tangled around any of our SWAT stowed bits and pieces.
As you’d expect from a top level bike, the groupset is SRAM’s XX1, while Rockshox’s 140mm Pike RCT3 fork controls the front end and a custom tuned Fox Float shock handles the rear. Specialized’s own finishing kit, including the new Command Post IRcc are present as are their carbon Roval Traverse SL wheels.
With the front end taken care of, Specialized has also worked on the back end of the bike. In order to create nice, short chainstays (437mm, down from 450mm) the seatstay bridge has been dropped. Instead, a beefier seatstay and larger linkages take up the slack. The shuttle that drives the shock has also been made more substantial. It seems to have worked, as we couldn’t notice any loss of rear-end stiffness. The short, tight back end feels responsive, balancing the quick handling of the short stays with stability from the big wheels.
A redesigned shock linkage boosts rear end stiffness
The custom tuned Fox Float CTD shock comes with Specialized’s AutoSag feature – pump the shock to 300psi, sit on the bike and release the pressure – automatically sagging it to 25 percent. From there you can easily play around to get it perfectly set up for you – although other than fiddling around with the rebound, we felt no need.
The rear shock has also been made more progressive, now better matching the Pike fitted up front in terms of trail support. As usual that gives 140mm of utterly predictable control and performance.
The 30mm internal width Roval Traverse SL rims, mated to their own brand 2.3in Butcher and Purgatory tyres means plenty of volume to the tyres, as well as a great profile which makes the most of the tyre’s shoulders to give stunning levels of grip.
Ride and handling: 29 inches of speed – can you keep up?
We tested the bike extensively in Rotorua, New Zealand and (although Rotorua’s hero dirt could make the most plastic of tyres feel great) the amount of cornering grip was exceptional in virtually every trail condition.
With dialled suspension, light wheels and epic levels of grip and control it’s no surprise that the new Stumpjumper S-Works is a very, very fast bike. While Specialized says the 650b version is ‘fun’ and the chubby tyred 6Fatty has loads of grip, it’s the 29er that its maker coins as ‘fast’.
Despite hitting trails blind, we were able to traverse rough, rutted, rooty and muddy lines at top speed. With the four-bar FSR suspension doing its job of staying active under braking we could stay off the levers later and later with the Shimano XTR Trail brakes and allow the tyres to take control of the cornering.
The Stumpjumper comes with a single ring setup, but it is possible to add a front derailleur
Up hills, the adjustment in the CTD shock was useful, although we only ever put it in Climb mode when we had to get out of the saddle to pedal.
Even though were rolling on big wheels, steering up front was never sluggish. However, it’s worth bearing in mind that we very quickly swapped the 75mm stem for a shorter 40mm model – something we’d recommend doing from the off. At 620mm for a size Large frame, the top tube is reasonably long, but the head angle has relaxed half a degree to 67.5 for 2016, meaning it’s nice and stable at speed without feeling like a barge in slow speed turns.
The new Command Post IRcc is similar to the old version, but along with its three main positions there are now 10 smaller indents along its length, making it possible to select a height between the three main ones should you wish. It takes a bit of a knack to get this right, but it’s a nice feature which adds versatility to the post.
The rider's nerve and ability are the only things tempering the S-Works Stumpjumper's appetite for pace
It’s not difficult to see why the Stumpy has remained so popular through the years. It’s a dependable bike that easily outperforms most bikes on the market.
The suspension is efficient and effective and the build is well thought out, as you’d hope when handing over this sort of cash. There are perhaps more efficient enduro race bikes out there, but they often lack character.
The Stumpy is an incredibly fast and fun machine, with the renewed back end keeping fun levels high, and it’s raw ability to hold speed is only tempered by your ability to hold on.
This article was originally published in What Mountain Bike magazine.