Specialized

Stumpjumper15 Comp Alloy

Claimed weight16.17 kg (35 lb, 10.4 oz) (size S4)Complete bike

FrameM5 Alloy chassis and rear…FOX FLOAT 36 Rhythm, GRIP d…

GroupsetShimano SLX, M7100, 12s…Shimano SLX, CS-M7100, 12…

WheelsSpecialized, hookless a…Butcher, GRID TRAIL casing,…

The 15th generation of the Specialized Stumpjumper unifies the brand's previously split trail bike lineup, merging the standard Stumpjumper and the longer-travel EVO into a single 145mm-travel platform. Designed to pair with a 150mm or 160mm fork, this iteration drops the asymmetrical sidearm frame brace of its predecessor in favor of a cleaner, more traditional silhouette. The defining feature of the new frame is the Fox and Specialized GENIE shock, a dual-chamber air spring developed to mimic the supple initial stroke of a coil while retaining the late-stroke progression of an air shock. Positioned as a highly adaptable trail bike, it caters to riders who want a single chassis that can be tuned for everything from long backcountry pedaling to aggressive, steep descents.

Specialized Stumpjumper

Year

Build

Size

$2,800See deal

01 / Buy

Where to get it.

No retailers stocking size S3.

Size

0 retailers · Size S3

No retailers carrying size S3 right now.

02 / Specifications

Spec sheet.

Every component shipped with this build.

01Frameset

4 components

FrameM5 Alloy chassis and rear-end, Trail Geometry, SWAT™ Door integration, head tube angle adjustment, threaded BB, internal cable routing, 12x148mm dropouts, sealed cartridge bearing pivots, SRAM UDH compatible, 145mm of travel

ForkFOX FLOAT 36 Rhythm, GRIP damper, two position Sweep adjustment, 15x110mm QR axle, 44mm offset, S1: 140mm travel, S2-S6: 150mm travel

Rear shockFOX FLOAT Performance with Specialized GENIE Shock Tech, Ride Dynamics Trail Tune, 2-position lever w/ LSR adjustment, S1: 210x52.5mm, S2-S6: 210x55mm

Weight16.17 kg (35 lb, 10.4 oz) (size S4)

02Drivetrain & brakes

10 components

Shift leversShimano SLX, M7100, 12spd

Rear derailleurShimano SLX, M7100, SGS, 12-speed

CassetteShimano SLX, CS-M7100, 12-speed, 10-51t

ChainShimano SLX, M7100, 12-speed

CranksetShimano SLX, M7120, 32T ring, 55mm chainline, S1-S3: 165mm, S4-S6: 170mm

Bottom bracketShimano, BB-MT801, Threaded

Front brakeTRP Trail EVO, 4-piston caliper, hydraulic disc

Rear brakeTRP Trail EVO, 4-piston caliper, hydraulic disc

Front rotor203mm

Rear rotorS1-S2: 180mm; S3-S6: 203mm

03Wheels & tires

4 components

Front wheelSpecialized, hookless alloy, 30mm inner width, tubeless ready, 29"; Specialized alloy front hub disc, sealed cartridge bearings, 6-bolt, 15x110mm thru-axle, 32h; DT Swiss Industry

Rear wheelSpecialized, hookless alloy, 30mm inner width, tubeless ready, S1-S2: 27.5", S3-S6: 29"; Alloy, sealed cartridge bearings, 12x148mm thru-axle, 28h; DT Swiss Industry

Front tireButcher, GRID TRAIL casing, GRIPTON® T9 compound, 2Bliss Ready, 29x2.3"

Rear tireEliminator, GRID TRAIL casing, GRIPTON® T7 compound, 2Bliss Ready, S1-S2: 27.5x2.3, S3-S6: 29x2.3"

04Cockpit & contact

5 components

StemAlloy Trail Stem, 35mm bar bore

HandlebarsSpecialized, 6000 series alloy, 6-degree upsweep, 8-degree backsweep. S1-S2: 780 width, 20mm rise; S3-S4: 800 width, 30mm rise; S5-S6: 800 width, 40mm rise

SaddleBridge Comp, Hollow Cr-mo rails, S1-S2: 155mm, S3-S6: 143mm

SeatpostX-Fusion Manic, infinite adjustable, two-bolt head, bottom mount cable routing, remote SLR LE lever, 34.9, S1: 125mm, S2: 150mm, S3: 170mm, S4-S6: 190mm

Grips/TapeSpecialized Trail Grips

03 / Geometry

Geometry & fit.

6 sizes published.

Specialized continues its S-Sizing approach, offering six frame sizes (S1 through S6) based primarily on reach rather than seat tube length. This allows riders to size up for high-speed stability or size down for a more maneuverable feel, aided by short seat tubes that accommodate long-travel dropper posts across the board. The S1 and S2 sizes come standard with a mixed-wheel setup, while S3 through S6 roll on dual 29-inch wheels, though all frames can be converted to a mullet configuration via an aftermarket linkage.

The geometry is highly tunable, featuring six distinct configurations. An adjustable headset cup allows the head tube angle to shift between a steep 65.5 degrees and a downhill-leaning 63 degrees. Meanwhile, a chainstay flip chip alters the bottom bracket height and rear center length. In its neutral settings, the bike features a relatively high stack and a steep effective seat tube angle. This combination places the rider in a comfortable, upright pedaling posture that keeps weight centered over the bottom bracket during steep climbs, while the generous reach provides a spacious and centered stance for descending.

Reach × Stack · size S3mm

Where the handlebar sits relative to the bottom bracket — the single most important fit pair.

01Fit geometry6 values

Stack627 mm

Reach450 mm

Top tube595 mm

Headtube length110 mm

Standover height745 mm

Seat tube length405 mm

02Component geometry5 values

Crank length165 mm

Handlebar width800 mm

Stem length40 mm

Saddle width143 mm

Dropper travel170 mm

03Handling geometry9 values

Headtube angle64.5°

Seat tube angle77°

BB height337 mm

BB drop38 mm

Trail130 mm

Offset44 mm

Front center780 mm

Wheelbase1213 mm

Chainstay length435 mm

Which size should I buy?

Slide your height to see the recommended size. GearWise's fit algorithm works from the published stack, reach, and ETT — the brand's own recommendation may differ.

Your height

5'8"173 cm

5'0"5'5"5'10"6'3"6'7"

Recommended sizeS3Based on stack, reach & ETT for your height · score 89/100.

→Calculated from GearWise's own stack / reach / ETT algorithm — the brand's size chart may recommend a different size, and a proper bike fit beats any calculator.

04 / Other builds

The lineup.

9 builds, ranging $3,000 – $12,000.

The Stumpjumper 15 lineup spans nine models, split between FACT 11m carbon and M5 alloy frames. A critical distinction between the materials is cable routing: the carbon frames are strictly designed for wireless electronic drivetrains and lack routing for mechanical shift cables, while the alloy frames retain traditional cable ports.

Suspension spec heavily dictates the bike's character. Most builds feature the signature Fox GENIE air shock paired with a 150mm fork. However, Specialized also offers dedicated coil builds—equipped with either Ohlins or Fox DHX coil shocks and longer 160mm forks—aimed at riders prioritizing aggressive descending over pedaling efficiency. Braking power is prioritized across the board, with nearly all models featuring heavy-duty four-piston calipers, like SRAM Maven or TRP DH-R EVO, paired with large 200mm or 220mm rotors.

Value varies significantly across the ladder. The entry-level alloy models offer an accessible price point but come with a noticeable weight penalty and basic suspension dampers. In the carbon tier, the Pro and Expert builds are frequently viewed as the sweet spot, delivering high-end Fox suspension and SRAM Transmission drivetrains at a substantial discount compared to the premium S-Works models.

2025S-Works 15 LTD

FOX DHX Live Valve Neo

$12,000

2025S-Works 15

SRAM XX AXS, FOX Factory

SRAM X0 AXS, FOX Factory

$8,000

202515 Expert

SRAM GX AXS, FOX Performance Elite

SRAM S-1000 AXS, FOX Performance

$5,000

2025 · Currently viewing15 Comp Alloy

Shimano SLX, FOX Rhythm

$4,000On this page

202515 Alloy

Shimano Deore, RockShox/X-Fusion

$3,000

05 / Reviews

From the press.

26 reviews from the cycling press.

Reviewers consistently praise the Stumpjumper 15 for its exceptional rear-wheel traction and composed descending manners, largely crediting the proprietary GENIE shock. On the trail, the dual-chamber design delivers "coil-like reactivity through that first 70% of the travel" (Flow Mountain Bike), allowing the rear wheel to track smoothly over roots and chatter. This translates to excellent climbing traction, with testers noting the bike maintains "all-out grip" (Theloamwolf) on steep, technical ascents where other trail bikes might spin out. When pushed hard downhill, the shock's aggressive late-stroke ramp-up effectively prevents harsh bottom-outs.

Despite the plush suspension, the bike retains an energetic character. Testers found the carbon models to be "gloriously flickable" (Enduro MTB), balancing agility with high-speed stability. However, the active suspension means it is not the firmest pedaler on smooth fire roads without utilizing the climb switch.

The primary criticisms center on weight and frame details. While the carbon models are competitively light, the aluminum versions carry a substantial weight penalty, with reviewers noting the alloy frame makes it "quite heavy for a trail bike" (PinkBike). Additionally, aggressive riders frequently found the stock tires and alloy wheelsets on lower-tier builds to be under-gunned for how hard the chassis encourages them to ride.