The Human Friendly Transmission is the marketing name of a proprietary continuously variable transmission (CVT) made by

Honda is a Japanese public multinational conglomerate manufacturer of automobiles, motorcycles, and power equipment, headquartered in Minato, Tokyo, Japan. Honda has been the world's largest motorcycle manufacturer since 1959, reaching a producti ...

for its motorcycles, including the Honda DN-01 and EVO6 concept motorcycle. The electronically controlled automatic transmission system is unlike more familiar belt-driven CVT systems used on scooters, nor does it have a

torque converter A torque converter is a type of fluid coupling that transfers rotating power from a prime mover, like an internal combustion engine, to a rotating driven load. In a vehicle with an automatic transmission, the torque converter connects the power ...

, typical of automotive applications. Instead it is a hydrostatic drive that employs a

variable displacement Variable displacement is an automobile engine technology that allows the engine displacement to change, usually by deactivating cylinders, for improved fuel economy. The technology is primarily used in large, multi-cylinder engines. Many automobil ...

axial piston pump with a variable-angle swashplate. Prior to the DN-01, this type of system had not been used in road-going consumer motor vehicles, though it is familiar in industrial applications and heavy equipment such as forklifts and the

US Air Force The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Sig ...

's MJ-1 bomb lift truck, in use since the 1950s. Honda has also dabbled in this technology since the 1950s. It appeared on their 2001 FourTrax Rubicon 4-wheel, off-road ATV. Honda DN-01 img 3225

The electronic controls allow the motorcycle to be operated in three modes: Drive, Sport and Manual. In Drive and Sport, it functions much like a CVT scooter, with infinitely variable gearing upshifted and downshifted automatically for what the system determines to be optimal performance. Unlike a scooter, engine braking is always available when decelerating. The difference between Drive and Sport modes is that Drive is optimized for economy while Sport is more responsive. In Manual mode, the transmission operates in one of six discrete gears chosen by the rider by pushing a plus/minus button on the left handlebar. It feels much like a normal motorcycle, including hitting the rev limiter at the top of each gear, but the

electronic control unit An electronic control unit (ECU), also known as an electronic control module (ECM), is an embedded system in automotive electronics that controls one or more of the electrical systems or subsystems in a car or other motor vehicle. Modern vehic ...

(ECU) prevents upshifting and downshifting too soon. In all modes, it automatically returns to the lowest gear when stopped. It is also possible to switch into neutral while stopped, unlike a scooter.

Notes

References

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External links

Motorcycle Picture Book , HFT (Human-Friendly Transmission)
Honda's animated visualizations of HFT operation (Adobe Flash). Motorcycle transmissions