The Specialized Stumpjumper Comp Alloy 27.5 12-Speed Mountain Bike 2020 delivers everything a trail-bike should, pairing a radically designed alloy frame with a well-rounded build kit.
Specialized haven’t forgotten about all the alloy fans out there. In fact, the new Specialized Stumpjumper Comp Alloy 27.5 with 12-speed SRAM NX Eagle may be the most radically designed alloy bike ever made. And with new tube shapes, and an asymmetrical design, it’s going to exceed all of your expectations of how a trail bike should ride.
The design goal for the new Specialized Stumpjumper was simple – build the ultimate trail bike, one that feels telepathic. And it turns out that this feeling all comes down to stiffness. Think of it this way: when the frame’s telling your hands one thing and your feet another, your brain gets confused with the imbalance and the bike feels unstable. In order to fix this, they had to get to work on dialing-in the materials, shapes, and the layout.
When designing the frame with the stiffness targets being a main goal, they developed a radical new sidearm design for the 2020 Stumpjumper. The front-end and rear-end are connected at three points, and the sidearm helps keep all these points super stiff and connected, all while saving vital weight at the rear-end. More explicitly, this minimizes frame flex when the rear suspension is active.
Continuing down the suspension path, both the fork and rear shock get a custom Rx Trail Tune. Suspension performance is highly dependent on frame, wheel, and rider size, so the Rx Tune allows for each bike to land in the middle of the adjustment spectrum, and this gives you the biggest possible range to fine-tune your ride. Another focal point of the tune for the Stumpjumper was matching the suspension characteristics between wheel sizes—we developed a specific Rx Tune for each platform. So, no matter what wheel size you prefer, you’ll get perfectly linear suspension.
Steps were also taken to make the Specialized Stumpjumper easy to live with. Threaded bottom brackets make a triumphant return, and there’s room for up to a 3.0″ tire. You’re also free to run whatever aftermarket rear shock you want, since the 2020 Stumpy uses standard metric shocks. Customization is furthered with a Flip Chip that lets you to dial-in your Stumpy to your riding style. Switch it from High to Low and it drops your bottom bracket 6mm and slackens the head tube by half-a-degree. Little details also jump out to surprise you, like a newly designed ribbed chainstay protector that makes chain slap a thing of the past and nearly silences the drivetrain.
The build on the 2020 Specialized Stumpjumper Comp Alloy 27.5 12-Speed comes with a list of components that deliver undeniable quality, like a 12-speed SRAM NX Eagle drivetrain, SRAM Guide R disc brakes, FOX front and rear suspension, and Roval Traverse 27.5 wheels.
Specialized Stumpjumper Comp Alloy 27.5 12-Speed 2020 Features
- The completely redesigned alloy Stumpjumper frame features an M5 alloy front and rear-end, an asymmetrical design, and the 29 Trail geometry, so it’s just the right amount of both capable and comfortable.
- Custom RX Tune is applied by the in-house Suspension Team, ensuring that it’s perfectly paired for the specific kinematics of the bike, riding in the sweet spot with an ideal range of adjustability.
- The Flip-Chip allows you to change the frame geometry with ease, tailoring the ride to your style & the terrain ahead. There are two settings, High and Low, adjusting bottom bracket height by 6mm and the head tube angle by half-a-degree.
- Ultimate adjustability with standard stroke eye-to-eye metric shocks, a threaded BB system and up to 3.0″ tyre clearance.
- A new chainstay protector makes the drivetrain virtually silent, as well as eliminating chain slap. This is done through nubs disrupting the slap of the chain to reduce its movement and noise.
2020 Specialized Stumpjumper Comp Alloy 27.5 12-Speed Build Highlights
- FOX Float Rhythm 34 GRIP Damper 150mm travel fork
- FOX Float DPS Performance shock
- SRAM NX Eagle 12-speed
- Roval Traverse 27.5 tubeless ready rims paired to Butcher/Purgatory 2.6″ tyres
- SRAM Guide R disc brakes
- X-Fusion Manic dropper post
|Frame||M5 alloy chassis and rear end, asymmetrical design, 27.5 Trail Geometry, threaded BB, fully enclosed internal cable routing, 12x148mm dropouts, sealed cartridge bearing pivots, replaceable derailleur hanger, 150mm of travel|
|Fork||FOX FLOAT Rhythm 34, GRIP Damper, 44mm offset, 2-position sweep adjust, 15x110mm, tapered alloy steerer, 150mm of travel|
|Rear Shock||FOX FLOAT DPS Performance, Rx Trail Tune, rebound and 3-position compression adjust, 210×52.5mm|
|Front Hub||Specialized, sealed cartridge bearings, 15x110mm spacing, 28h|
|Rear Hub||Specialized, sealed cartridge bearings, 12x148mm thru-axle, 28h|
|Spokes||DT Swiss Industry|
|Rims||Roval Traverse 27.5, hookless alloy, 30mm inner width, tubeless ready|
|Inner Tubes||Presta, 40mm valve|
|Front Tyre||Butcher, GRID casing, GRIPTON® compound, 2Bliss Ready, 27.5×2.6″|
|Rear Tyre||Purgatory, GRID casing, GRIPTON® compound, 2Bliss ready, 27.5×2.6″|
|Crankset||SRAM NX Eagle, DUB, 170mm|
|Bottom Bracket||SRAM DUB, threaded BB|
|Shifters||Sram NX Eagle, trigger, 12-speed|
|Rear Derailleur||SRAM NX Eagle, 12-speed|
|Cassette||SRAM NX Eagle, 12-speed, 11-50t|
|Chain||SRAM NX Eagle, 12-speed|
|Front Brake||SRAM Guide R, hydraulic disc, organic pads, Guide S4 4-piston caliper, 200mm|
|Rear Brake||SRAM Guide R, hydraulic disc, organic pads, Guide S4 4-piston caliper, 180mm|
|Handlebars||Specialized Trail, 6061 alloy, 8-degree backsweep, 6-degree upsweep, 27mm rise, 780mm, 31.8mm clamp|
|Grips||Specialized Sip Grip, half-waffle, S/M: regular thickness, L/XL: XL thickness|
|Stem||Specialized Trail, 3D-forged alloy, 4-bolt, 6-degree rise|
|Saddle||Body Geometry Phenom Comp, Adaptive Edge design, hollow Cr-Mo rails, 143mm|
|Seatpost||X-Fusion Manic, infinite adjustable, two-bolt head, bottom mount cable routing, remote SRL LE lever, 34.9mm, S: 125mm, M/L/XL: 150mm of travel|
|Seat Binder||Alloy, 38.6mm|
Specialized Men’s Bike Sizing Guide
We have put together a general sizing guide for Specialized mountain, road & hybrid bikes. The table below is a general guideline to sizing, for an accurate guide to each Specialized model and also how to measure yourself.
|Rider Height||Suggested Bike Size|
Specialized Men’s Mountain Bikes
|5’2″ – 5’6″||S|
|5’6″ – 5’10”||M|
|5’10” – 6’2″||L|
|6’1″ – 6’4″||XL|
|6’4″ – 6’6″||XXL|