Specialized Stumpjumper 15 Comp Alloy 29/27.5 2025

Stumpjumper 15 Alloy is here to obliterate every trade-off in the trail game. Devour bumps like a big bike? Check. Short-travel control, playfulness, and efficiency? Double check. How about a heaping helping of personalization to make it perfect for the only rider who really matters-you? Check, check, check.
BREAKTHROUGH CAPABILITY: GENIE Shock Technology combines a poppy, playful ride with a bottomless DH feel.
ULTIMATE CONTROL: Measurably better traction than 'Bike of the Year' Stumpjumper EVO.
UNMATCHED PERSONALIZATION: Six-way geometry adjustment, mixed wheel or 29', tunable spring curve, and more.
GENIE-The Magic Carpet Ride: The biggest innovation on the Stumpjumper 15 Alloy is GENIE. This patent-pending air spring technology we invented grants every trail rider three wishes: the maximum grip and traction of a coil spring feel, better bottom-out prevention than a standard air spring, and the ability to tune mid-stroke and end-stroke support independently.
ILLUMINATING GENIE: GENIE combines the control-enhancing linear spring rate of a coil spring through the 'bump zone' with the progressive spring rate of an air spring at the end of the stroke to avoid bottom-outs. Truly, it's the best of both worlds - coil and air - with extra tunability. Say goodbye to compromises and hello to the future of riding.
WHAT BUMP?: With 16.3% better bump force management than a traditional air-sprung shock, GENIE makes the Stumpjumper 15 Alloy ride like a bike with more travel. For example, the Stumpjumper 15 Alloy (with 145 mm rear wheel travel) and our Enduro (170 mm travel) both use 101 mm of travel to absorb a 1080 N bump force.
TRACTION GALORE: Extensive field testing proves that Stumpjumper 15 Alloy with GENIE delivers 57% better traction than a standard air-sprung shock because GENIE technology gives you supple, coil-like performance, which keeps the wheel in contact with the ground a greater percent of the time than a typical air spring would.
BYE, BYE, BOTTOM-OUTS: 39% fewer bottom-outs than a standard air spring. During big hit events, you benefit from the rising rate in the last 30% of the GENIE stroke. Because of this two-stage, pronounced rising rate, GENIE reduces the frequency and severity of bottom-outs.
HONED GEOMETRY: This bike's geometry delivers big bike capability when you need it, a nimble feel in tight sections, and lively, efficient climbing manners. The generous cockpit centers you on the bike, optimizing traction and corner control. The low bottom bracket, slack head tube angle, and optimized fork offset keep things stable in the rough.
Specifications
Drivetrain
Chain
Shimano SLX, M7100, 12-speed
Bottom Bracket
Shimano, BB-MT801, Threaded
Crankset
Shimano SLX, M7120, 32T ring, 55mm chainline, S1-S3:165mm, S4-S6: 170mm
Rear Derailleur
Shimano SLX, M7100, SGS, 12-speed
Cassette
Shimano SLX, CS-M7100, 12-speed, 10-51t
Shift Levers
Shimano SLX, M7100, 12spd
Frameset
SWAT
SWAT internal downtube storage
Frame
M5 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
Seat Binder
Alloy, 38.6mm
Suspension
Fork
FOX FLOAT 36 Rhythm, GRIP damper, two position Sweep adjustment, 15x110mm QR axle, 44mm offset, S1:140mm of travel, S2-S6:150mm of travel
Rear Shock
FOX FLOAT Performance with Specialized GENIE Shock Tech, Ride Dynamics Trail Tune, 2-position lever w/ LSR adjustment, S1:210x52.5mm, S2-S6:210x55mm
Brakes
Front Brake
TRP Trail EVO, 4-piston caliper, hydraulic dis