Whenever Specialized introduces an updated version of the Stumpjumper the MTB-world holds its breath for a moment. Specialized launched the original Stumpjumper back in 1981 making it the world’s first production MTB. Today – 37 year on – the Stumpjumper is still regarded as a benchmark and trendsetter in the MTB industry. We came to Spain with Specialized and tested the latest incarnation of the legendary trail bike.

No other mountain bike category has changed as radically as trail bikes have over the last years – and the Stumpjumper has always played a crucial role in this development. A few years back bikes with a travel between 120 mm and 150 mm were still considered tame touring rigs but today they’re more powerful than ever and represent the most versatile mountain bike category.

The Stumpjumper 2018 introduces itself with an asymmetrical frame and a radical new look but still maintains its original character.

When looking at the new Stumpjumper the new asymmetrical frame is the first detail to catch your eye. The aim of this extraordinary design is to create the stiffest-possible connection between your feet and hands. An additional strut to the right of the shock connects the top tube with the seat tube and effectively forms two smaller frame triangles. This trick allows for a stronger connection between the contact points and leads to a more natural ride and better feedback from the trail. On the non-drive side the shock is freely accessible – a design we already know from Specialized’s Demo downhill-bike.

Two-Faced: The new asymmetrical rear end lends the Stumpy an eccentric look – the new version is almost impossible to confuse with the previous model.

The new extravagant rear end has entirely new kinematics which are finely tuned to the characteristics of modern shocks. The new rear end offers more support in the mid-stroke and allows you to run the suspension with less compression damping. This, in turn, improves the overall response of the rear end. The strong end progression offers plenty of reserves and prevents bottoming out on messy landings or big drops.

Chance Ferro worked on the rear suspension in his role as Ride Dynamics Program Manager: “Our goal for suspension performance was to create the most linear, supple and supportive suspension system. Tons of testing went into manipulating the leverage ratio and air spring volumes. The end combination of larger volume negative springs, a more progressive leverage ratio and reduced compression damping, gave us the suspension package we were after.”

The newest Stumpy generation waives the popular AUTOSAG feature and renounces any kind of proprietary technology. This means that in future all Stumpjumper models will come with standard metric shocks. An integrated flip-chip allows you to adjust the head- and seat-angle by half a degree and lower the bottom bracket by 6 mm. Speaking of bottom brackets the new Stumpy turns its back on Pressfit and embraces the proven BSA standard once again – nice move!

To the left the new BSA-threaded bottom bracket shell. To right the older version with Pressfit standard. Despite the compact size and the elegant lines it’s now even lighter and stiffer.

According to Specialized, the new frame is stiffer and lighter. In addition, all carbon models now feature a carbon-swingarm – the new Comp-model weighs a whopping 550 g less than its predecessor. Specialized’s engineers worked hard to find the optimal carbon-layup and finally reached the perfect compromise between stiffness and flex in every frame size. Little by little additional carbon layers were wrapped around the lightweight raw frame until the bike’s riding characteristics matched the idea of the development team.

Jason McDonald is MTB Design Engineer at Specialized and the man behind the carbon frame: “We started the project over two years ago, which sounds like a lot of time but when you put so much focus into every last detail of the bike time seems to fly by. Focusing on everything from frame layout/stiffness to kinematics/shock tune to SWAT to cable routing and all the small details of chainstay protector, downtube protector, chain guide, etc… takes a huge team and a lot of time. In the end, we are extremely happy with the way the bike turned out and can’t wait to see them on the trail!”

A clever system of nylon-guides inside the frame allows for an incredibly easy and clean cable routing – the cable-guide runs uninterruptedly from the head tube all the way back to the rear derailleur. This time around the SWAT door is integrated much deeper into the frame and sits flush with the frame edge and also offers 20% more storage room.

The ingenious SWAT door in the down tube is integrated much more elegantly and now sits flush with the frame edge.
The nylon cable guide merges seamlessly into the rear triangle and allows the shifter cable to run from the head tube to the rear derailleur without interruption.
Small details testify for the enormous development efforts. The undulated chainstay guard was designed to prevent the chain from oscillating.
On the S-Works model the multi tool hides inside the head tube. On the other models it’s still attached to the bottle holder.

The new Stumpjumper keeps up with the times and is no longer compatible with 2-speed drivetrains. As with the Enduro, the new Stumpjumper comes with a 34.9 mm seatpost diameter and there’s a brand new dropper to go with it. The Command Post IRcc features a 16-position height-adjustment and 160 mm drop on frame sizes M to XL.

La Familia – Specialized Stumpjumper model overview

Specialized introduced a total of three new Stumpjumper models – all of them with the option of either 27,5” or 29” wheels. The standard model has no fancy suffix in its name and replaces Specialized’s popular trail bike. You can get this with either 29” wheels and 150/140 mm of travel or 27.5” wheels with 150/150 mm of travel. The Stumpjumper ST (Short Travel) replaces the Camber and has 130/130 mm of travel on 27,5” models and 130/120 mm travel on the 29” versions. The Stumpjumper EVO sports a strongly downhill-oriented geometry and has the same amount of travel as the standard model.

The Stumjumper ST replaces the Camber and is the bike with the shortest travel in the Stumpy family
Model 27,5″ travel f/r 29″ travel f/r
Stumpjumper ST 130/130 130/120
Stumpjumper 150/150 150/140
Stumpjumper EVO 150/150 150/140
What a beast: the Stumpjumper EVO is back and is now stronger than ever – it features its very own frame and an extremely slack geometry.

All 27.5” models are compatible with tire widths of up to 3.0″ and all 29″-bikes can take tires up to 2.6″ or can even be converted to a 27.5” x 3.0″ setup. The frames of the Stumpjumper and Stumpjumper ST are identical and the geometry and travel only change because of the different shock, rocker link and fork. Apart from this, the spec is pretty much the same – with the biggest difference being the tires. The Stumpjumper rolls on 2.6″ rubber and the ST model relies on classic 2.3″ tires. The Stumpjumper EVO has its very own frame design and features a more downhill-oriented spec.