Automatic and semi-automatic motorcycles are becoming increasingly popular, but outside of the scooter segment, most manufacturers rely on electronically controlled manual transmissions instead of continuously variable transmissions (CVT). CFMoto seems to want to change this: A newly filed patent shows a parallel-twin engine combined with a belt-driven CVT transmission.
While CVT transmissions are standard on scooters and ATVs, they have so far hardly become established on larger motorcycles. A well-known example of a motorcycle with this technology is the Aprilia Mana, a V2 model with CVT. Despite these approaches, the breakthrough into the mass market has failed to materialize. But with more and more riders wanting to do without a clutch and gearshift, this could change. Yamaha offers a semi-automatic solution with the Y-AMT, BMW has developed the ASA system and KTM also relies on automatic shifting with the AMT. In this environment, CFMoto’s approach with a CVT motorcycle could offer a new option.
How the CVT transmission works
The continuously variable transmission works with two pulleys, each consisting of two conical halves. One pulley is connected to the engine via a centrifugal clutch, while the other is connected to the drive output, in this case a cardan shaft, via a bevel gear. The two halves of the pulleys can move towards or away from each other, which changes their effective diameter. A V-shaped belt transmits the power between the pulleys. The transmission ratio changes depending on the position of the pulleys: If the front pulley becomes larger and the rear pulley smaller, the output speed increases. If the front pulley becomes smaller and the rear pulley larger, a lower gear is created, which reduces the speed but increases the torque.
New engine with variable valve timing?
The unit shown in the patent is a parallel twin with chain-driven, double overhead camshafts (DOHC). A component on the gearwheel of the intake camshaft that resembles a camshaft phasing unit is striking. This detail is not explained further in the patent, but its shape suggests that it is a variable control for the intake valves. This could ensure better power delivery, depending on engine speed and load.
Although it is not certain whether this engine is intended for a motorcycle or an ATV – the cardan shaft could indicate off-road use – the patent explicitly names a motorcycle as the intended use for the drive.
Comparable concepts from China
Even though CFMoto itself does not yet have a CVT motorcycle in its range, there is already a similar concept from another Chinese manufacturer. Lifeng, better known under the “Regal Raptor” brand, has presented a motorcycle with a CVT transmission that is equipped with a CFMoto engine. However, this is not the unit shown in the patent, but a 963 cc V2 engine from CFMoto’s CForce 1000 ATV, ZForce 950 side-by-side and UForce 1000 utility vehicle. This engine produces 71 hp (52 kW) and has a simpler SOHC valve control system.
However, the Regal Raptor motorcycle weighs in at a considerable 355 kg (783 lbs), so despite its power, it is unlikely to deliver outstanding dynamics.
Conclusion
It remains to be seen if and when CFMoto will bring a motorcycle with a CVT onto the market. However, the patent shows that the company is working on such a technology. In a market where semi-automatic transmissions are becoming increasingly important, a continuously variable automatic transmission could be an interesting alternative for riders who want to do without manual shifting.
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