Biperformance Development Corporation (BDC) manufactures its state-of-the-art transmission control system for OEM motorcycle applications, the ShiftFX Electronic Shift Transmission (EST). The system builds on existing gearbox design, adding a sleek, simple rider interface to provide push-button semi-automatic or fully automatic shifting.
One of the main components of the ShiftFX EST is a state-of-the-art Active Clutch with isolation valve, which retains the standard clutch lever for operation by the rider at any time. Using a high-tech shape-memory alloy, the Active Clutch is an elegant and unique design that allows electrohydraulic control of the clutch in a unit weighing less than half a kilogram. This technology has seen very limited use in automotive applications, and the Active Clutch is the first commercial motorcycle application for shape-memory alloy. An added benefit of the Active Clutch is that it retains the standard clutch lever that has direct connection to the clutch slave cylinder. The ShiftFX EST relies on an auto-clutch for launching and anti-stall.
In the Active Clutch, an additional master cylinder, operated by a shape-memory-alloy actuator, is inserted into the clutch hydraulic system and can electronically control the clutch. An isolation valve is incorporated such that at any time, the manual clutch can be used to override the system. Customer feedback in this regard has been clear: the presence of a manual clutch override lever is essential. Instances where manual clutch override is preferred over automatic control include:
- Emergency stopping
- Starting aggressively from standstill
- Fail-safe backup
- Coasting over slippery terrain at speed
- Dislodging a rear tire stuck in mud, snow, gravel
- Rolling the bike in gear, with the engine off
- Bleeding the hydraulic circuit after servicing
The Active Clutch weighs less than half a kilogram and measures just 105 x 36 x 46mm. Its design retains the direct connection from hand lever to slave cylinder, preserving manual clutch action and feel. This feature is the basis for US patent 7,591,358.
Read more about the ShiftFX Electronic Shift Transmission and Active Clutch here: http://shiftfx.com/electronic-shift-transmission.