In a world shifting toward electrification and hyper-efficiency, what does it mean for Harley-Davidson® to unveil its most powerful V-twin ever? The 2025 Harley-Davidson® CVO™ Road Glide® ST with the Milwaukee-Eight® 121 High Output engine isn’t just another iteration of Harley-Davidson®’s big
twin legacy—it’s a declaration. A statement that even as the industry leans into batteries and automation, there is still a place for raw, mechanical emotion. This is H-D®’s reaffirmation of its performance philosophy in the 21st century.
The Business of Power: A Strategic Move or a Passion Project?
Did the market demand the Milwaukee-Eight® 121 High Output, or is this H-D®’s way of planting a flag in the sand? The 2025 Harley-Davidson® CVO™ Road Glide® ST isn’t a bike designed for mass appeal. It’s a halo product—a machine that speaks directly to Harley-Davidson®’s core audience while
making sure the rest of the industry is paying attention. As emissions regulations tighten and investment shifts toward electric platforms, ICE innovation is slowing. Yet here, Harley-Davidson® is doubling down on high-performance touring V-twins. It’s a calculated move that reassures its
premium clientele while keeping the brand culturally relevant in the face of technological upheaval.
The Evolution of the Milwaukee-Eight®: Where Do You Go After Perfection?
H-D® has been refining the Milwaukee-Eight® since its debut, pushing from 107 to 114, 117, and now 121 cubic inches. But is this latest iteration an evolution, or is it the final crescendo of a legendary powerplant? The 121 High Output boasts a higher compression ratio, revised camshaft timing,
and an optimized intake for a more aggressive power delivery. These aren’t incremental tweaks; they represent Harley-Davidson® squeezing every ounce of performance out of the platform before the inevitable shift toward hybrid or electric solutions.
The Experience: How This Powertrain Interacts With the Rider
Numbers don’t tell the whole story. A seasoned rider is looking for horsepower and would want to know how it’s delivered. The increased bore and stroke enhance combustion efficiency, resulting in a more immediate throttle response. Precision oiling ensures the engine stays cool under sustained high-load conditions, vital for long-haul touring. Meanwhile, the SHOWA® suspension and revised chassis geometry work in harmony to translate all 115 horsepower into controlled, confident road manners. Harley-Davidson®’s engineers understand that sheer output means nothing without balance, and that’s exactly where the 121 High Output shines.
The 115-HP Question: Is It Enough, or Are We Reaching the Ceiling?
Harley-Davidson®’s decision to stop at 115 horsepower raises an important question: is that enough in today’s performance landscape? European rivals like the BMW K1600 and Ducati V4 GT easily surpass 150 hp, yet H-D® isn’t playing the numbers game. Instead, the focus is on usable power—the kind that matters on real-world roads, not just spec sheets. The torque-rich nature of the Milwaukee-Eight® remains the defining trait, offering instantaneous grunt without the need for extreme revs. This restraint is strategic; it’s about maintaining H-D®’s core rideability while ensuring reliability remains uncompromised.
The End of an Era or the Start of Something New?
Does the Milwaukee-Eight® 121 High Output represent the peak of H-D®’s combustion engine development, or is it just the beginning of a new performance wave? H-D® has already dipped into the electric market with the LiveWire, but is there space for both high-output V-twins and future electric advancements under the same brand? If this is the final evolution of H-D®’s iconic V-twin, it’s a hell of a way to go out. But if this is just a stepping stone, we could be looking at the dawn of a new breed of American muscle touring.
The 121 High Output – A Milestone or a Monument?
A decade from now, we may look back at the Milwaukee-Eight® 121 High Output as the peak of H-D®’s combustion legacy—the last great internal combustion V-twin before electrification took over. Or, we may see it as the first step toward an entirely new performance era, where H-D® finds a way to merge its traditional muscle with the demands of a modern world. Either way, the 2025 Harley-Davidson® CVO™ Road Glide® ST and its monstrous V-twin make one thing clear: H-D® isn’t done making statements just yet.
Ready to feel the Milwaukee-Eight® 121 High Output for yourself? Visit Orange County Harley-Davidson® in Irvine, CA, and schedule a test ride today. See firsthand what makes this engine a revolution in the saddle. Don’t just read about the future of Harley-Davidson® performance—ride it.
