2025 Specialized Stumpjumper 15 Alloy Bike

Built for riders who want one bike to handle everything, the Specialized Stumpjumper 15 Alloy (2025) blends a rugged M5 aluminum frame with a mullet wheel setup that pairs a 29-inch front and a 27.5-inch rear. Roughly 150mm of fork travel and 145mm out back let it plow through rough sections while staying nimble on tight, twisty singletrack. The payoff is a planted, confidence-building ride that still loves to be pushed.

Why we like it:

The mixed-wheel layout is the real trick here, giving you the rollover and grip of a big front wheel with a smaller rear that whips through corners and pops off features.

Who it's for:

Ideal for trail and all-mountain riders chasing a versatile rig that climbs efficiently and descends with composure, from mellow flow trails to chunky backcountry lines.

Highlights:

The frame is Specialized's M5 alloy in a mixed 29/27.5 wheel configuration. Suspension comes from a RockShox Psylo Silver fork with roughly 150mm of travel matched to an X-Fusion O2 Pro RL air shock delivering about 145mm at the rear. Shifting is handled by a Shimano Deore M6100 12-speed drivetrain with a wide 10-51 cassette for steep climbs, and Shimano MT420 four-piston hydraulic disc brakes with 180/203mm rotors supply the stopping power.

Things to consider:

This is a versatile mid-travel trail bike that climbs and descends confidently. It is not a dedicated downhill or long-travel enduro bike, so the most extreme, roughest terrain may call for more travel.