World’s First Automatic Sportbike
Honda Motor Co., Ltd. announced that it has developed a motorcycle Dual Clutch Transmission (*1), the world’s first (*2) fully automatic motorcycle dual clutch transmission for large-displacement sport bikes. The new transmission provides riders sporty riding enjoyment with easy operation, while its superior transmission efficiency delivers fuel economy equal to or better than a conventional manual transmission. A new VFR large-displacement sport bike equipped with the new transmission will be released in Europe and North America in 2010, with sales to commence in Japan at a later date.
This world’s first motorcycle dual clutch transmission features a light, compact design that allows it to be combined with existing engines without substantial layout modification. Further, the new transmission delivers the precise acceleration control riders require thanks to electronic control technology that helps ensure smooth, seamless gear changes.
In order to respond to rider demands in a broad range of situations, the transmission is equipped with three operating modes, two full-auto modes (D-mode for regular operation and S-mode for sporty riding); and a 6-speed manual mode, which delivers the same shift feel as a manual transmission. Honda intends to gradually expand the deployment of the new transmission to more and more of its large-displacement motorcycles, particularly sports models destined for use in developed countries.
The new transmission features a dual clutch transmission configuration in which independent clutches are employed for the odd gears (1st, 3rd, 5th) and the even gears (2nd, 4th, 6th), respectively. The two clutches operate alternately to effect gear changes. For example, when changing from 1st to 2nd gear, the computer detects the up-shift and engages 2nd gear, then releases the 1st-gear clutch while engaging the 2nd-gear clutch to achieve a seamless gear change.
While some dual-clutch transmissions tend to be bulky, the new system employs original technologies such as dual input shafts, exclusive in-line clutch design, and concentration of hydraulic circuitry beneath the engine cover to achieve a compact design. Compactness and lightness is further enhanced through the use of a simple shift mechanism design based on that of a conventional motorcycle shift drum. Optimized shift scheduling achieves fuel economy equal to or better than that of a fully manual transmission, enabling Dual Clutch Transmission to deliver both sporty riding and environmental performance combined.
Honda will continue to deliver motorcycles that match the needs of society and users’ lifestyles, spreading the joy of riding and mobility.
(*1) Patents pending: 100
(*2) According to Honda survey