Bike Test: The Specialized Stumpjumper FSR Expert Carbon Evo 650b

We have never witnessed a more low-key new model introduction from Specialized than the one for their first 27.5-inch wheeled offering, the Stumpjumper FSR Expert Carbon Evo 650b. We figure the reason is that the crew at Specialized is still totally enamored with their 29er offerings–and with good reason. Like we said in our S-Works Epic 29 review (April, 2014), mountain bikes just don’t get any better.

So, while they seemingly dragged their feet on this 27.5 thing (Specialized is the last major brand to release a 27.5-inch wheel model), the Stumpjumper FSR Expert Carbon Evo 650b sneaked quietly into the [Mountain Bike Action] test fleet and then blew us away.


This bike totally blurs the lines. Its target is the “aggressive” trail rider, a term we use for lack of a better description. Face it, for every minute of “aggressive” trail, there are hours of climbing or riding more manageable terrain. Specialized understands this and doesn’t take the Evo so far in the aggressive direction that it is a burden the other 80 percent of the time.



This Evo gets upgraded from the 26er version (the 27.5s will phase out Specialized 26er models) with a Specialized FACT 9m carbon FSR frame upgrade, the same frame used on their 29ers, and a specific rear end for the 27.5-inch wheel. Like other Evo models (Evo means evolutionary modification from the stock model), this one gets a slacker, lower Evo geometry; 5.9 inches of rear-wheel travel; full-cartridge bearing pivots; a PF30 (press fit) bottom bracket; and 142-millimeter-wide dropouts. Look closely and you’ll see a 10-millimeter machined aluminum spacer between the headtube and fork crown. This slackens the steering geometry and also gives you the option to add a longer-travel fork (removing the spacer would preserve the steering geometry) or remove the spacer and leave the stock fork on for a quicker-handling bike (albeit one with a lower bottom-bracket height).


The Specialized Command Post dropper seatpost with internally routed remote actuation cable is a must-have accessory for this bike that you won’t have to buy. The custom Fox Float CTD Factory shock has an additional ring and valve wrapped around the air sleeve. This little extra is dubbed Autosag, and as the name implies, this technology automatically adjusts the shock’s sag to meet Specialized’s recommended setting in three easy steps.

The five-star RockShox Pike fork is always a welcome sight. The attention to detail means you get a Specialized Butcher Control tire up front for bite, a Specialized Purgatory Control tire in the rear for better rolling, and brake rotors sized to match the job at hand (7 inches up front and 6 inches in the rear).

The bike has a Specialized SWAT (Storage, Water, Air, Tools) system that includes a bottle cage, downtube-mounted multi-tool, a hidden chain tool and a spare link hidden in the headset’s top cap.

 Spec-2Spec-3 Spec-5


The setup: The shock’s Autosag is a simple feature that takes the guesswork out of setting the rear suspension’s sag. You pump the shock up to a ridiculously over-pressurized 300 psi, sit on the bike (wearing your riding gear), depress the red Autosag valve and remain still until airflow stops. You now have the sag dialed to 20 percent of the suspension’s travel. Set the shock’s rebound to your preference; set the fork’s sag and rebound, and go ride. You’re done.

The fit: A spacer under the head tube, a borrowed front triangle, and a unique rear end might sound like a Frankenstein bike. Wrong. The Evo feels right as soon as you take to the saddle. The rider is centered and low, like he is sitting inside the bike. Specialized gives you ample standover clearance, and the frame, stays and linkages are narrow and never come in unwanted contact with the ride.

Moving out: Flip the shock to Trail or Climb mode to reduce the rear end’s activity and roll out. The big tires, long travel and dropper seatpost all add up to a bike that should be over 30 pounds, but this Evo feels lighter at the pedals than its amazing 28.5-pound actual weight.

Cornering: The Evo has relaxed steering, but don’t take that to mean “heavy” or “sluggish.” The wide handlebar and short stem encourage the rider to experiment with line changes while the tires and suspension make small work out of everything from braking bumps to soft corning surfaces.

Climbing: The 1×10 drivetrain’s strength is for descending, but it is a limiting factor for those riders with a bit of extra ballast or less fitness than an enduro racer. Those riders are better served by a traditional Stumpy. If you have the fitness and determination, the Evo will get you up the climbs. If the climbs are loose and nasty, it will even beat the regular Stumpy. We did find that the bike responded well to out-of-the-saddle surges without losing too much grip at the rear wheel.

Descending: You can get so lazy on this bike! Drop the seatpost. Don’t even bother with picking the “smooth” line; keep your butt in the saddle and just motor away. If you aren’t the lazy type, get out of the saddle (you will be centered), keep your torso low to the bar and expect to set your personal best. The Evo honestly feels like a lightweight downhill bike.

Braking: It almost seems impossible to lock the rear wheel. The thing just stays glued to the ground. A rider can go really deep into a corner before braking. The trick is learning not to overdo it on the braking. Let the bike do its thing and don’t unnecessarily scrub speed.



Convert the tires to tubeless. That’s really it. For our hard-packed trail surfaces, we could try a tire with a less aggressive knob pattern on the rear, but we wouldn’t do that until we had ridden the knobs off the stocker.


Think of the Evo as what a bike fanatic would do to a Stumpjumper if he wanted to increase its downhill capability without killing its overall performance. The thing is, Specialized did it for you. Calling the Evo a mini-downhiller isn’t a stretch. It is that good at descending without forcing its rider to suffer or hike the trail up.

Is it better than the 26er version? No question. In every aspect. Is it better than the 29er version? For some riders, absolutely. Riders who have tried 29-inch wheels and miss the liveliness of the 26er will migrate towards this bike. Also, those who feel the 29er is too big will favor this bike.

After spending time on the Stumpjumper FSR Expert Carbon Evo 650b, we seem to understand why Specialized didn’t make a big deal out of its release. They are going to let its riders do all the talking.



Mountain Bike Action is a monthly magazine devoted to all things mountain biking (yes, that’s 12 times a year because we never take a month off of mountain biking). It has been around since 1986 and we’re still having fun. You can start a subscription by clicking here or calling (800) 767-0345. Also available from the Apple Newsstand for reading on your iPad, iPhone or iPod Touch.

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