The Roehr 1250sc is the fastest and most powerful American made production sport bike. The specially developed supercharged version of the Harley-Davidson* Revolution* engine provides unmatched power. This power is combined with our innovative BiMetal composite beam frame, top quality cycle parts and sleek styling. The result is a motorcycle that redefines the American performance bike. Hand crafted, exclusive, fast and beautiful. A true modern American thoroughbred.
The Roehr Supercharging System (RSS)
The specially developed Roehr Supercharging System (RSS) provides the 1250sc with class leading power and torque outputs. But, just as important as outright power is the way the power is delivered. RSS provides smooth controllable power responding to the riders commands.
At the heart of RSS lies the patented Rotrex (C15-60) centrifugal supercharger unit. This supercharger provides the highest levels of efficiency and performance in a compact, light weight unit. This unit weights only 6.4 lbs. and is no larger than a typical small car alternator. Combined are a high efficiency, highly developed "Turbo" centrifugal compressor section, mated to a patented planetary roller drive mechanism. This drive mechanism provides an extremely high step-up ratio of 12.7/1 as well as very low noise output, low wear and excellent reliability.
RSS is designed to provide boost upon rider demand. A special bypass valve is employed to recirculate unneeded air back into the compressor during certain operating ranges such as idle, cruise and deceleration, this effectively disconnects and unloads the supercharger, thus reducing parasitic drag and increasing engine efficiency. In this mode, the engine operates as it's stock normally aspirated self.
Under acceleration the bypass valve closes allowing compressor air to pressurize the intake plenum. The Rotrex supercharger delivers air in proportion to it's driven speed. As engine speed increases the supercharger air output increases proportionally. This strategy is responsible for the extraordinarily smooth and linear power delivery. Power increases in proportion to engine RPM all the way to redline.
RSS enables efficient engine operation with stock emission output levels. Due to the relatively low boost levels of the RSS and low intake charge temperature increase relative to other supercharger types, an intake charge intercooler is eliminated, contributing to a lighter and more compact system.
The Engine (production version)
The heart and soul of a motorcycle is its engine. It determines the feeling and overall character of a motorcycle. Just as important as outright power is the way that power is delivered and the sound emitted from the exhaust, giving the motorcycle it's voice.
The Roehr 1250sc is powered by a 180hp, specially developed version of the Harley-Davidson* V-Rod* engine. The engine was designed by Harley Davidson in cooperation with Porsche AG. It is loosely based on the Harley-Davidson VR1000 superbike engine. The design goal was to create a new engine that was modern, powerful and reliable providing HD with an engine for the future.
The result was an 1130cc (now available in 1250cc) liquid cooled, DOHC, eight valve, 60 degree, V-Twin engine with a performance like large bore short stroke architecture. This engine was named the "revolution" engine.
The Revolution engine debuted in the 2002 Harley-Davidson V-rod power cruiser and was widely praised for its excellent power, near perfect power delivery and soul stirring exhaust note.
It is only fitting that the Roehr 1250sc would take this great American power plant back to its roots and unleash it's racing bloodline in a new American superbike.
Roehr Motorcycles has applied its Roehr Supercharging System (RSS) technology to enhance this engine's power output without changing the character of it's power delivery, resulting in a truly thrilling riding experience. The result is the most powerful American production motorcycle engine available.
