Specialized Stumpjumper 15 Expert Mountain Bike 2025 - Trail Full Suspension MTB
The Genie Shock
It’s the new Fox Genie shock that allows the Stumpjumper 15 to feel like a lightweight trail bike while offering the confident abilities of an enduro rig. Developed with Fox the Genie is very supple off the top with good mid-range support and plenty of big hit ability.
Specialized claim, that compared to a regular air shock, the Genie offers 57% more traction along with massive bottom out resistance.
How The Genie Works
The Genie is a dual chamber shock that offers a two-stage spring rate. Through the first 70% of travel both chambers are open which offers a linear spring rate for a very supple, sensitive feel. When the shock reaches the last 30% of travel the outer chamber is shut off which reduces the air volume, so the spring rate ramps up dramatically offering incredible bottom out resistance.
Capability And Control
The Stumpjumper 15’s geometry is similar to the award winning Stumpjumper EVO which offers a confident riding position. You get big bike capability when you need it, a nimble feel in tight sections, and lively, efficient climbing manners. The generous cockpit centres you on the bike, optimizing traction and corner control. The low bottom bracket and slack head tube angle keep things stable in the rough.
Adjustable Geometry
The Stumpjumper now features 6-way adjustable geometry. You can easily adjust the head angle between 63° and 65.5° via a unique eccentric upper headset cup. You can also fine tune the bottom bracket height and chainstay length using the flip chip in the rear stays. This means that you can personalize the feel of the bike to your own preferences, or for particular trail conditions.
Size Specific Features
The Stumpjumper 15 uses Specialized’s S-Sizing system which allows you to select the size to suit your riding style. It’s nice to see that chainstay length is size specific too on this new bike.
*The four larger sizes come with 29” wheels front and rear while the smaller S1 and S2 sizes come with a 27.5” rear wheel and a 29” front wheel. There is one exception to this in that that there is one model with an Ohlins coil shock that comes with a 27.5” rear wheel in all sizes. An aftermarket shock link is available if you want to fit a 27.5” rear wheel on a full 29er.