Last September, CFMoto surprised everyone by unveiling two camouflaged prototypes of its two new sports bikes. We talk about the CFMoto 675RR and 500SR. The first equipped with a 675 cc three-cylinder engine, while the second has a 500 cc four-cylinder engine. Recently, the Chinese company has filed patent applications related to the engine of the 500SRwhich offers us a first glimpse of its interior.
Although CFMoto continued to show the three-cylinder 675 cc engine in its CFMoto 675SR during the EICMA last November, confirming its design and making some vague claims about its performance, including power over 100 hp and a redline starting at 12,300 revolutions.
Until now, the 500SR remained an enigma. Although a prototype of our protagonist was seen carrying out dynamic tests on a track in China last year, along with the 675SR. Both bikes were heavily camouflaged to hide technical and design details, but apart from the recognizable sound of a 500 cc (half-displacement) four-cylinder engine, not much else was revealed.
CFMoto Engine Secrets
The new patent applications focus on technical aspects of the engine, such as a cooling system designed to quickly bring the engine up to operating temperature, likely to meet strict emissions standards that include cold-start testing. However, the documents also contain detailed diagrams of the engine, clearly showing its design and internal parts.
From the images it can be deduced that the engine is an original design from CFMoto, which is notable considering the scarcity of 500cc inline-four engines on the market today. It is a conventional, high-performance engine, with features such as chain-driven double overhead camshafts, four valves per cylinder with hub tappets, and coil-over-plug electronic ignition.
The engine includes a conventional six-speed transmission and an offset wet sump to accommodate the exhaust system. In terms of performance, it is expected that the 500SR is located below the 675SR in the hierarchy of CFMotooffering an approximate power of 80 hplocated between the 3-cylinder with more than 100 HP and the current twin-cylinder of 449 cc and 50 HP (sold as 450SR in Spain).
The CFMoto 500SR features a street sportbike design similar to that of the Kawasaki Ninja ZX-4RR, with handlebars higher than those of a pure supersport. The front end and tank are designed to allow a greater steering angle, with a particular focus on aerodynamics, including covers to channel air to the calipers, plus discs on the rear wheel to optimize airflow.
Of course, it also features radial-mount brakes, an inverted fork, a belly-mounted exhaust system, and a tall, compact rear end that might not be very comfortable for potential companions.
When it is presented later this year, the CFMoto 500SR It will represent another step in the unexpected resurgence of small-capacity four-cylinder engines. A class that seemed destined to disappear due to strict emissions standards and the trend towards parallel twin engines, which are much cheaper to manufacture. Good for CFMoto