Specialized Stump Jumper 15 Alloy frame 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 thry 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 the 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.

Ride your way
The Stumpjumper 15 Alloy seamlessly integrates benchmark geo adjustability, making it the most personalizable trail bike ever. Six distinct geometry settings allow you to hone performance for any style, any terrain. The head angle and bottom bracket height can be fine-tuned for stability or clearance.

Wheel choice
With the aftermarket shock links, you can choose between big wheels front and rear or mix things up with a 27.5” rear for a more responsive and playful ride. No matter what you choose, geometry is unaffected.

Carry it all
SWAT on Stumpjumper 15 Alloy elevates downtube storage, an innovation thry pioneered.

More relentless than you
The full-suspension bikes are built to be relentless, designed to endure years of hard riding, and backed by the best support and policies to keep you on the trail. the unbeatable lifetime, no-questions-asked replacement suspension pivot bearings to the original owner is just one way they've got you covered.

Features

All-new M5 alloy frame with SWAT door integration
Ride Dynamics tuned FOX FLOAT Performance with Specialized GENIE patent-pending air spring technology provides maximum grip and traction found in a linear coil spring, bottom-out prevention found in a progressive air spring, and the ability to tune mid-stroke and end-stroke support independently. 2-position open and firm damper adjustments.
Lifetime replacement of suspension pivot bearings to the original owner

Tech Specs

Frameset

• 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
• SWAT: SWAT Internal Downtube Storage

Suspension

• 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

Weight

• Producer's weight: 4.31 kg (9 lb, 8.0 oz)
• Weight Size: S4

Producer's weight: Weights based on production painted frames as pictured. Actual weights will vary based on colorway, frame size, and component variation. Specifications are subject to change without notice.