Specialized Stumpjumper Expert



Words by Joe Mackey | Photos by Spencer Rathkamp

The Specialized Stumpjumper is one of the most iconic mountain bikes of all time. The name is loaded with history and over the years, it has been a standard in the mountain bike community. The previous generation rolled out at Sea Otter in 2018 with an all new aesthetic and key technology upgrades like a threaded bottom bracket and updated metric shock sizing. While there was plenty to revel in, the geometry was extremely conservative, and the bike was far from being an efficient climber. Many folks loved the new Specialized Stumpjumper, however many were also less-than-thrilled with its climbing and some other missing pieces.  Fast forward to 2020 where the unimaginable can happen and Specialized has released an all new Stumpjumper that is in the process of changing my mind about trail bikes.

Specialized Stumpjumper Expert

Similar to the Specialized Stumpjumper EVO, launched just a couple weeks ago, there isn’t a ton from an aesthetic standpoint that has changed with the shorter travel Stumpy, there isn’t that sense of shock and awe. One of the biggest changes being the Missing Link or move from a Horst Link suspension to single-pivot. This shouldn’t come as a massive surprise as Specialized has moved away from FSR in favor of single pivot with their Epic and Epic EVO XC bikes. Single-pivot suspension designs are known for better pedaling efficiency and climbing ability, but historically have had compromises from a kinematic standpoint when descending. Specialized (and a few other brands) have an answer for that compromise: Flexstays.

Flexstays have been around for a long time on everything from aluminum to carbon bikes and there have even been some bikes introduced this year with flex stays such as the Cannondale Scalpel and Scalpel SE. The Stumpjumper uses flexstays in the seatstays (say that five times fast) to improve climbing and pedaling efficiency while being able to keep composure on rowdier descents. There are some weights saving to accompany this design, a whole 55-grams actually, or essentially a healthy-sized apple fritter from your favorite donut shop. With the new suspension design Specialized went with a new RX tune using Fox’s digressive piston with a healthy amount of low-speed compression to help with the pedaling support but also keep the suspension active through the mid-stroke. Essentially, they didn’t want the suspension to pack up at high speeds and remain active when needed most.

Specialized Stumpjumper Expert

The Stumpjumper also got an overhaul on the geometry side of things with Specialized using their “S” sizing system. Each size got a little longer in the reach department and a little slacker. The new Stumpy uses a flip-chip to adjust the geometry that changes the bottom bracket height and reach by about 5-millimeters. Each size has a specific carbon layup and design to accommodate different sizes riders for optimum stiffness and ride performance.

Of course this generation of Stumpjumper has a threaded bottom bracket and uses a SWAT Box that has even more storage than before. The SWAT Box got a complete overhaul that increased storage capacity, increased frame strength and stiffness, but did add 80-grams to the frame weight. Total frame weight with all hardware is coming in at a very lean 2,420 grams for the size S4 (large-ish).

This Stumpjumper will be available in five different builds with one S-Works, three mid-level carbon builds and two aluminum offerings. All of them are equipped with 29-inch wheels but are mullet ready in case you’re feeling trendy or bored.

Specialized Stumpjumper Expert

Sadly due to the massive fires I wasn’t able to get the yachting experience that our other tester Cole got when he was introduced to the Stumpjumper EVO, but I was happy to get time on my home turf in Southern California. My local trails are well-suited for single-pivot equipped bikes with long fire road climbs, high speed flow and plenty of loose berms. Specialized mailed me the Expert build equipped with SRAM GX Eagle, G2 brakes, Fox Performance suspension and an X-Fusion dropper. Cockpit was a mix of in-house aluminum Specialized products and some comfy Deity grips. The build kit has been pretty solid although I’m not a huge fan of the 10-52 cassette combined with 30-tooth front ring. Most riders will be able to go with a 32-tooth up front and not lose out on the climbs.

There is a familiarity with any Specialized I’ve tested in the past. I can swing a leg over the bike and feel comfortable almost immediately, which is odd to me considering I’ve never owned a Specialized. The new Specialized Stumpumper had that familiar feeling and was quick to feel settled. I’ve been running the rear SAG at 13mm, which is what Specialized recommends and have felt comfortable on most terrain. I will be playing with the shock more as I move along with my long-term testing. The GRIP2 damper in the fork can complicated for some, but once its dialed is about as good as it gets.

Specialized Stumpjumper Expert

I couldn’t help but reflect on the previous generation Stumpy in my mind when I hit my first long, fire road climb and honestly was expecting the same feel from this bike. I was wrong, very wrong. From the start the new Stumpy felt more like a cross-country bike opposed to a trail bike. It is a spirited climber that, regardless of shock setting, by nature, feels and is efficient. There is a little more support when the shock is flipped into the middle setting but over time I’ve left the shock open whether climbing or pedaling on flat.

So far the bike has been an absolute shredder when hitting the descents. The geometry is a nice mix of playful and capable while leaning in a progressive direction. The longer reach has given me a confident position on steep, loose descents and allowed me plenty of wiggle room to move back over the rear tire. At higher speeds the shock has felt active and playful even under hard braking on steep sections. At 5’9 on my tallest day, I’m riding an S3 comfortably, although the stock 150mm dropper post does feel a tad short for how little seat tube there is. Long term I’ll be moving to a longer 175 or 180.

Specialized Stumpjumper Expert


I’ve never considered myself a Specialized fanboy by any means but this bike has started to sway me. Thus far the new Stumpjumper has proven to be an efficient climber and plenty capable when dropping into rough and fast downhill singletrack. Every ride seems to be chipping away at my memories of what used to be and brings more smiles to my face. The bike really impressed me on the way up and is more than ready to get down. I look forward to spending more time aboard this bike in the future as I stack miles for a long-term review.

Weight: 28lbs

To learn more, visit Specialized.com