Motorcycle Active Clutch

The Kinitics Automation clutch actuator is a main component of the ShiftFX Electronic Shift Transmission (EST), a state-of-the-art transmission control system for OEM motorcycle applications. The system, manufactured by Biperformance Development Corporation (BDC), builds on existing gearbox design, adding a sleek, simple rider interface to provide push-button semi-automatic or fully automatic shifting.

The Active Clutch Actuator

The Active Clutch, a clutch actuator with isolation valve, 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 actuator 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:

The Kinitics Automation active clutch used in the BDC Electronic Shift Transmission.
  • 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.

Click to read more about the ShiftFX Electronic Shift Transmission and Active Clutch.