Taking a look at my Specialized Stumpjumper EVO, you might be unimpressed at first. It looks hot, for sure, but the graphics and branding are minimal. Look closer and you’ll start to notice the little clues that this is anything but a stock bike.
Here you’ll find an overview of the editor’s dream bikes.
Cruising along in the car, a pair of headlights dazzle you in the rearview mirror. As they approach, you see it’s just a beat-up estate car. “Where did that come from?” The road opens up and you floor the accelerator. The family car stays on your tail. “Brrrraaaaap!” The beat-up estate leaps around you like you’re standing still, flames lick from the popping exhaust leaving a haze of scorched petrol. That was no 1.6 litre diesel! You just encountered a ‘sleeper.’ That’s precisely what I have built. A Specialized Stumpjumper sleeper.
A trail bike with big ideas. Why did I choose the Specialized Stumpjumper EVO?
The frame choice for my bike was easy. When it comes to crazy trail bikes, nothing comes more certifiable than the Specialized Stumpjumper 29 EVO S3. Just look at the numbers: 475 mm reach may not be a big surprise but the 47 mm bottom bracket drop, 63.5° head angle and 1252 mm wheelbase will make you spit out your coffee! It’s absolutely bonkers for a 140 mm travel trail bike and is perfect for pointing down the steepest trails. The closer you look, the more you see that everything on my Specialized Stumpjumper EVO has been tuned to the max. While the brakes may be basic SRAM CODE R levers and callipers, the front rotor is a monster. The 2 mm thick, 223 mm GALFER rotor gets clamped between my favourite Trickstuff Power+ pads which provide outrageous stopping power and are unflappable on even the steepest tracks. If you’re not careful, you’ll stop so violently that you have to hold onto your spleen. GALFER G1652 Semi-metallic pads, developed for heavier eMTBs, sit in the rear calliper to give me maximum heat resistance on long, sustained descents.
Fork Fox 36 Rythm mit Grip 2 Upgrade 150 mm
Shock Fox Float DPX2 tuned 140 mm
Brakes SRAM CODE R, Galfer 223/203 mm
Drivetrain SRAM NX Eagle
Seatpost Bikeyoke Revive 180 mm
Stem ONEUP Components EDC Stem 35 mm
Handlebar Spank Spike 35 Vibrocore 820 mm
Wheels Spank Tuned 359/350, Cushcore Inserts
Tires Maxxis Minion DHF 2.5″ / DHR II 2.4″
The suspension has received some work too. Suffice to say, it only looks stock. The standard FOX DPX2 shock was easily overwhelmed on big hits, blowing through its travel without a fight. To combat this, I changed the 0.36 in3 volume spacer for the bigger 1.02 in3 one which gives the shock more muscle and support in the mid- and end-stroke. To increase small bump sensitivity, I also removed one volume reducer from the negative chamber. However, it’s up front where the significant changes have been made. The functional, but somewhat unsexy FOX Rhythm 36 fork, fitted as standard on my doner bike, has been completely reworked by the FOX service centre. The ‘satisfactory’ GRIP damper has been replaced with the far superior GRIP2 version. With full control over compression and rebound and improved damping, the fork sticks to the ground like shit to a blanket. Some might question whether it wouldn’t have been easier to throw on a FOX Factory 36 to benefit from the EVOL air chamber, but the bling-bling Kashima coating clearly wouldn’t keep to the ‘sleeper’ image I’m trying to cultivate.
Reducing vibration for maximum grip
Grip is paramount. What I want is a damped feeling through contact points, where I can feel what I’m riding on without getting exhausted on bumpy terrain. Vibration means fatigue, especially on the long runs in the Tweed Valley, so I went on a damping and compliance mission. You’ll find no stiff carbon bars or harsh carbon wheels here. The SPANK SPIKE 35 handlebar was an easy choice: thin-walled aluminium injected with vibration damping Vibrocore foam. I paired this with the expensive but effective RevGrips Race grips, which provide a small amount of adjustable ‘suspension’. Vibrocore foam is also hidden in the SPANK SPIKE wheels. which with a 30 mm internal width make the perfect companion to the ultimate rubber on the market, MAXXIS Minion DHF WT and DHRII WT tires. On the subject of hidden technology, inside the new OneUp stem is a smart multi-tool with everything you need should if you have a problem on the trail. Eagle-eyed readers will also have noticed the green valve core on the rear wheel, indicating a CushCore insert inside. As well as offering additional puncture protection, this also stabilises the feel of the tire on the rear at the 20–22 psi pressures that I run. The build is finished off with a SRAM NX Eagle drivetrain. This utilitarian option is simple and effective and does the job without fuss, though the NX cassette adds substantial weight.
Unless you’re fully committed, the Stumpjumper EVO will highlight ALL your weaknesses. Does that make it a bad bike? No, not at all. It’s what makes it unique.
Living with the Specialized Stumpjumper EVO ‘Sleeper Project’
I have to admit that the start of our relationship wasn’t all smooth sailing. The 16.15kg Stumpjumper EVO is such a radical machine that you can’t just jump off a ‘normal’ trail bike and go full gas – you need to ride it differently. In fact, at first, I had a growing suspicion that the bike was trying to kill me. I’ve had my most roost-exploding-hell-yeah moments, but also some of my biggest crashes. The EVO is a rowdy beast for sure. Ground-skimmingly low with a crazy-slack head angle, you have to white-knuckle the grips to push it to the limit. But get it right and it’s like riding a firework. The geometry is adjustable and in the low setting the BB height is bordering on ridiculous, basically pedal striking on the flat. I did something that I never do and put it into the high setting, raising the bottom bracket 6 mm and steeping the head angle to a still-slack 64°. This transformed the bike into a much more balanced ride with easier-going handling – but you know what, I missed the madness and lowered it again.
Owning the Specialized Stumpjumper EVO is a bit like rallying an old 911 down a country road. Intoxicating fun, but lose concentration and it will spit you into the trees.
I am delighted with the components I chose. Robust and reliable, they have all stood up to a summer of being bashed into things. The SPANK Vibrocore components have proven to be more than just marketing bullshit. The damping and compliance at the bar and wheels have given the bike a noticeably buttery feel over small bumps, transmitting minimal buzz from the trail. This EVO is smooth as silk. Combined with the RevGrips it’s perfect for long top-to-bottom runs on the steep terrain of my home trails. Corners require a slightly different technique – with the super slack 29er angles you really have to drive the front wheel and push it into the tight stuff. This lightens up the rear wheel considerably and you can expect to be going sideways. A lot.
Where the Stumpjumper EVO has most impressed me is with its ability to maintain effortless speed down even the steepest trails. The ludicrously slack head angle and low-slung chassis mean that even when I am thundering wide-eyed and white-knuckled down a precipitous gradient, I never feel exposed or unbalanced. Rather than hanging off the back and praying, I can keep my weight up front, pushing hard on the bar to maintain grip. The extremely low BB builds confidence during critical turns on the steepest slopes and like a pro-snowboarder, it carves beautiful lines. I was worried when I chose this bike that I would find it lacking in rear travel but the Stumpjumper EVO has reinforced my belief that geometry is king. I have built a highly specialised bike for very special terrain. It’s exactly on my home trails that this is the sleeper that you won’t see coming!
Is the Stumpjumper EVO easy to ride? No! Do I love it? Hell yes!
My Specialized Stumpjumper EVO Sleeper project is everything I wanted it to be. Unruly, crazy and hard to handle, but ultimately intoxicating and addictive fun. It’s the sort of bike that rewards committed riding and punishes indecision. With compliant components and brakes powerful enough to pull my face off, it taunts me a little every ride. That’s why I love it so much!
- insanely fast on steep natural trails
- SPANK's Vibrocore
- components give a smooth ride
- RevGrips minimise arm pump
- bonkers in every way
- the handling is anything but balanced
- mid-travel suspension does not match extreme geometry
- the suspension is easily overworked if you ride bike parks
This article is from ENDURO issue #040
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Words & Photos: Trev Worsey