What Our Gearhead(R) Experts Are Saying: "This frameset is a cheat code for modern trail builds-GENIE gives coil-like grip with big-hit support, the 145mm rear end pedals clean, and the six-way geo makes 29 or mixed-wheel setups easy. SWAT 4. 0 swallows tools and layers, threaded BB and UDH keep service simple, and the Di2-only compatibility cleans up the cockpit for a dead-quiet ride."We love how Specialized boiled big-bike confidence and trail bike pop into one chassis, and the Stumpjumper 15 EVO Frameset is the heart of that ride. Drop GENIE into the mix and we get the playful feel we want with the bottomless control we need-perfect for a custom build that lives on real-world trails. GENIE's two-phase air spring feels coil-calm through the bump zone, then ramps decisively to mute harsh bottom-outs. The result is 145mm of rear travel that rides bigger, with measurably better traction and control, while the six-way geometry adjustment and aftermarket links let us choose 29/29 or a mixed-wheel setup without warping the handling. SWAT 4. 0 storage, a threaded BB, internal routing, and UDH compatibility make it a builder's dream-and electronic-drivetrain-only keeps the cockpit clean and quiet for the long haul.