Tested: Specialized Stumpjumper Comp Alloy

You could spend less, but don't. You could spend more, but why?


130-millimeter rear travel, 140 front
29-inch wheels
Alloy frame


Smart spec
Perfect geometry for the category
6 sizes, including XS and XXL


Just barely outside the "budget" category
Rattly dropper cable





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If there was one category of bike that dominated 2020, it was … well, it was whatever bike you could get your hands on. It’s been slim pickins’ out there. But among them, the aggressive, short-travel 29er has grabbed much of the spotlight. Bikes like the Transition Spur, YT Izzo and new Evil Following proved (again) that less can be more. But those bikes really wanted to make a big deal about it. As if it was somehow newsworthy that good geometry, good parts and moderate travel was a perfect combination.  This year’s Specialized Stumpjumper, on the other hand, is low-key on-trend. It even shed the ‘ST’ (short-travel) qualifier that the previous 120mm version took on soon after it replaced the Specialized Camber. Now, it’s just the Stumpjumper. A name that, in 1981, graced the downtube of what is widely considered the world’s first production mountain bike.

Forty years later, the Stumpjumper is now a 130-millimeter-rear-travel, 140-millimeter-front-travel 29er. Specialized’s flagship S-Works Stumpjumper is a $9,500 trail / XC crossover that, thanks to its full carbon frame and flex stays (a weight-saving feature that replaces a couple suspension pivots with frame tubes meant to flex as the shock compresses), weighs under 27 pounds. What I tested here is not that bike. Specialized offers two lower-priced alloy models in the 2021 Stumpjumper lineup. You can get in on the bottom floor with the Stumpjumper Alloy for $2,400, but this is the higher-end of the two metal models, the $3,200 Stumpjumper Comp Alloy.

Specialized stumpjumper comp alloy

The two share the same frame, but the parallels stop there. The Comp Alloy gets a few minor upgrades like wider, name-brand rims, a more reliable dropper seatpost and a SRAM NX drivetrain that offers the same 455-percent gear range (12-speed 11-50 cassette) as the base model’s SX, but has a more refined fit and finish. What really makes the extra $800 worth spending, though, are the cranks, brakes and suspension. The Comp’s NX cranks use SRAM’s robust, cutting-edge DUB oversized spindle compared to the base model’s questionable Powerspline bottom bracket. Its brakes are SRAM’s 4-piston G2 R, more powerful than the base model’s 2-piston Tektros. Both models do run a huge 200mm rotor up front and 180mm rear, which was great to see. But the real reason the Comp is the model to get is the suspension. The Fox Float DPS Performance rear shock and Fox 34 Rhythm GRIP fork offer performance that, for many riders, will be indistinguishable from Fox’s flagship suspension. 

Specialized stumpjumper comp alloy

The base model is by no means a bad value. In fact, that 1981 Stumpjumper, a steel bike with rim brakes and no suspension, went for $750. In 2021 dollars, that’s about $2,160, just $240 less than this year’s base-model Stumpy. But the Comp Alloy truly leaves nothing to be desired. I found myself reaching for the Stumpy long after I’d put in enough time to review it. One reason this category is gaining so much traction, is that these bikes encourage, and reward you for, putting the power down. Being used to significantly lighter bikes, I nevertheless didn’t ever feel the Stumpy was slowing me down. Really, the only thing I missed from the carbon version is its more refined cable management. While most modern carbon bikes route the leads silently against the inner walls of the frame tubes, alloy frames leave them to rattle freely. The Stumpjumper Comp Alloy happens to do an excellent job keeping the brake and derailleur controls locked down, but not the dropper post cable. If you value your sanity, have the shop install a noise-damping foam tube before you put down your credit card.

Specialized stumpjumper comp alloy

It says a lot that a rattling cable was the most noticeable performance sacrifice when going alloy. Within reason, light weight is overrated, particularly on bikes that are already decent at going uphill. Specialized’s perennial Horst Link suspension platform may not be known for being supportive under heavy torque, but it was only on the most manic standing climbs that I noticed it sinking at the apexes of my pedal strokes. Anyway, on punchy, rough sections, it’s worth the slight sacrifice in pure pedaling efficiency to have suspension that’s allowed to move freely. This is where bikes like the Ibis Ripley (and competitively priced Ripley AF) challenge the Stumpjumper Comp Alloy. The Ripley is a bit better at ‘hovering’ over rough climbs, regardless of pedal input. But when you’re not deep in the Stumpjumper’s travel, it tends to have more get-up and go. That’s why seated pedaling was truly flawless. The steep 77.2-degree effective seat tube angle and moderate travel are enough to mask even my clumsy pedal strokes. On quick loops, I found myself with no excuse not to up my output and squeeze in a little bonus descending. On long loops, it’s the kind of climber that disappears under you and lets you just settle in and pedal it out. 

Specialized stumpjumper comp alloy

Good climbing, though, is the easy part for a bike like this. It may be high praise that the Stumpjumper climbs like a bike with less travel, but it’s far higher praise that it descends like one with more. I, for one, usually prefer more. My personal daily driver has about 30 millimeters more travel, front and rear, than the Stumpjumper Comp Alloy. But I wasn’t about to waste my weekends on mellow trails. I dove in, elbows out, and tried to find this bike’s limits. 

This is why, if you have the means, I recommend springing for the Comp AL model. The GRIP damper on the Fox Rhythm 34 fork is remarkably supportive for being ‘entry-level’ in the usually high-end brand’s lineup. But more than that, you get an infinitely adjustable compression damping knob that was once unheard of on forks that are at this price point and are meant for ‘normal’ trail bikes. After some quick trial and error adding an air volume spacer for some extra ramp, and a quarter turn of compression damping, I rarely ever felt myself forced out of a neutral, comfortable position over the bike. That fork alone is probably most to thank for how good this bike is when being thrown in over its head.

Specialized Stumpjumper Comp Alloy

Second to that is its spot-on geometry. You can swap between two subtly different geometry positions on the Stumpjumper Comp Alloy, and in the lower, slacker position, the 65-degree head angle is just a shade more forgiving than what you might expect on a bike like this. And the 445mm rear-center is just a shade longer. Both kept it from being the ultra-playful, big BMX bike that some people may want out of this category, but again, I wanted to put it in enduro territory. The ingredients Specialized combined make this the perfect category-defying trail bike. And it does it without having an unorthodox fit. The S4 size (comparable to other brands’ large size) has a reasonably modern 475mm reach. At the S5 size, that number jumps to 500, and for the too often overlooked giants out there, there’s even an S6 size at a whopping 530 millimeters. Those get also-whopping 455mm rear-centers. And another nice touch, especially at this price point, the S4 and S5 sizes get 170mm dropper seatposts, and S6s get 200s. The dropper itself also has the rare feature of actually taking advantage of the larger 34.9 diameter Specialized has been pushing for a few years. The internals and upper tube are also larger, leading to a stiffer, stronger and hopefully longer-lasting post. It’s an example of the smart spec throughout the build. The 200mm front rotor shows Specialized knew the speeds this bike was capable of, and I needed every bit of it. And the house-brand Butcher and Purgatory tires, using some newly refined rubber recipes, are a perfect mix of chunky tread and supportive casing, without being too wide and marshmallowy for a bike with so much get-up-and-go.

Specialized stumpjumper comp alloy

That get-up-and go has never been a novelty for the Stumpjumper. This has always been what you might call a ‘normal’ bike. It’s the center point on the bell curve that is the right tool for the largest amount of jobs. And although this is a few hundred bucks north of what you might call a budget bike, it packs the kind of versatility that, in itself, usually comes at a premium. The new Stumpjumper is redefining mid-travel, without being all in-your-face about it.

Find it at specialized.com/stumpjumper

Photos: Satchel Cronk

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